Variation in sexual reproduction in orchids and its evolutionary consequences: a spasmodic journey to diversification

Biological Journal of the Linnean Society - Tập 84 Số 1 - Trang 1-54
Raymond L. Tremblay1, James D. Ackerman2, Jess K. Zimmerman3, Ricardo N. Calvo4
1Department of Biology, 100 carr. 908, University of Puerto Rico-Humacao, Humacao, Puerto Rico 00971–4300
2Department of Biology, PO Box 23360, University of Puerto Rico-Rio Piedras, San Juan, Puerto Rico 00931–3360
3Institute for Tropical Ecosystem Studies, University of Puerto Rico, PO Box 21910, San Juan, Puerto Rico 00931–1910
4Department of Biology, University of Miami, Coral Gables, FL 33124 USA

Tóm tắt

Từ khóa


Tài liệu tham khảo

Aagaard, 1999, Genetic variation among populations of the rare clustered lady-slipper orchid (Cypripedium fasciculatum) from Washington State, USA, Natural Areas Journal, 19, 234

Ackerman, 1975, Reproductive biology of Goodyera oblongifolia (Orchidaceae), Madroño, 23, 191

Ackerman, 1981, Pollination biology of Calypso bulbosa var. occidentalis (Orchidaceae): a food-deception system, Madroño, 28, 101

Ackerman, 1983, Euglossine bee pollination of the orchid, Cochleanthes lipscombiae: a food source mimic, American Journal of Botany, 70, 830, 10.1002/j.1537-2197.1983.tb06420.x

Ackerman JD 1985 Pollination of tropical and temperate orchids Tan KW Proceedings of the eleventh world orchid conference. 98 101

Ackerman, 1986a, Mechanisms and evolution of food-deceptive pollination systems in orchids, Lindleyana, 1, 108

Ackerman, 1986b, Coping with the epiphytic existence: pollination strategies, Selbyana, 9, 52

Ackerman, 1989, Limitations to sexual reproduction in Encyclia krugii (Orchidaceae), Systematic Botany, 14, 101, 10.2307/2419054

Ackerman JD 1995 An orchid flora of Puerto Rico and the Virgin islands Memoirs of the New York Botanical Gardens

Ackerman, 1991, Patterns and maintenance of extraordinary variation in the Caribbean orchid Tolumnia (Oncidium) variegata, Systematic Botany, 16, 182, 10.2307/2418982

Ackerman, 1997, Variation in pollinator abundance and selection on fragrance phenotypes in an epiphytic orchid, American Journal of Botany, 84, 1383, 10.2307/2446136

Ackerman, 1979, Pollination biology of Listera cordata (Orchidaceae), American Journal of Botany, 66, 820, 10.1002/j.1537-2197.1979.tb06288.x

Ackerman, 1985, Longevity of euglossine bees, Biotropica, 26, 44, 10.2307/2389109

Ackerman, 1990, Short and long term limitations to fruit production in a tropical orchid, Ecology, 71, 263, 10.2307/1940265

Ackerman, 1985, Reproductive biology of Oncidium variegatum: moon phases, pollination and fruit set, American Orchid Society Bulletin, 54, 326

Ackerman, 1996, Hurricane aftermath: resiliency of an orchid-pollinator interaction in Puerto Rico, Caribbean Journal of Science, 32, 369

Ackerman, 1994, A meager nectar offering by an epiphytic orchid is better than nothing, Biotropica, 26, 44, 10.2307/2389109

Ackerman, 1996, Seedling establishment in an epiphytic orchid: an experimental study of seed limitation, Oecologia, 106, 192, 10.1007/BF00328598

Ackerman, 1999, Genetic variation in a widespread epiphytic orchid: where is the evolutionary potential?, Systematic Botany, 24, 282, 10.2307/2419553

Adelson, 2001, From aardvarks to apples and orchids to ostriches: The simple evolutionary roots of a world of biological complexity and biodiversity, Scandinavian Journal of Clinical and Laboratory Investigation, 61, 13, 10.1080/003655101317095365

Agnew, 1986, Self-compatibility/incompatibility in some orchids of the subfamily Vandoideae, Plant Breeding, 97, 183, 10.1111/j.1439-0523.1986.tb01049.x

Alcock, 2000, Interactions between the sexually deceptive orchid Spiculaea ciliata and its wasp pollinator Thynnotuineria sp. (Hymenoptera: Thynninae), Journal of Natural History, 34, 629, 10.1080/002229300299480

Alexandersson, 1996, Population size, pollinator visitation and fruit production in the deceptive orchid Calypso bulbosa, Oecologia, 107, 533, 10.1007/BF00333945

Alexandersson, 2000, Genetic structure of the nonrewarding bumblebee pollinated Calypso bulbosa, Heredity, 85, 401, 10.1046/j.1365-2540.2000.00777.x

Aragón, 2001, Density effects on the reproductive success and herbivory of Malaxis massonii, Lindleyana, 16, 3

Aragón, 2004, Does flower color variation matter in deception pollinated Psychilis monensis (Orchidaceae)?, Oecologia, 138, 405, 10.1007/s00442-003-1443-9

Arditti, 1976, Post-pollinations phenomena in orchid flowers, a pictorial view, Orchid Review, 84, 261

Arditti, 2000, Tansley review, 110. Numerical and physical properties of orchid seeds and their biological implications, New Phytologist, 145, 367, 10.1046/j.1469-8137.2000.00587.x

Arduino, 1996, Genetic variation and natural hybridization between Orchis laxiflora and Orchis palustris (Orchidaceae), Plant Systematics and Evolution, 202, 87, 10.1007/BF00985819

Arft, 1998, Allopolyploid origin and population genetics of the rare orchid Spiranthes diluvialis, American Journal of Botany, 85, 110, 10.2307/2446560

Atwood, 1985, Pollination of Paphiopedilum rothschildianum: brood-site deception, National Geographic Research, 1, 247

Ayasse, 2000, Evolution of reproductive strategies in the sexually deceptive orchid Ophrys sphegodes: how does flower-specific variation of odor signals influence reproductive success?, Evolution, 54, 1995, 10.1111/j.0014-3820.2000.tb01243.x

Bänziger, 1996, The mesmerizing wart: the pollination strategy of epiphytic lady slipper orchid. Paphiopedilum villosum (Lindl.) Stein (Orchidaceae), Botanical Journal of the Linnean Society, 121, 59

Barkman, 2001, Evolution of vegetative morphology in Mount Kinabal high-elevation endemics: Insights from the Orchid genus Dendrochilum, Sabah Parks Nature Journal, 4, 9

Barkman, 2002, Hybrid origin and parentage of Dendrochilum acuiferum (Orchidaceae). Inferred in a phylogenetic context using nuclear and plastid DNA sequence data, Systematic Botany, 27, 209

Barnett, 1984, The initial effects of fire on orchids in a Stringybark-Box forest, Victorian Naturalist, 101, 188

Barraclough, 2001, Evolutionary rates and species diversity in flowering plants, Evolution, 55, 677, 10.1554/0014-3820(2001)055[0677:ERASDI]2.0.CO;2

Barrowclough, 1993, Variance of lifetime reproductive success: estimation based on demographic data, American Naturalist, 141, 281, 10.1086/285473

Bartareau, 1994, The reproductive ecology of Dendrobium toressae (Bailey) Dockr., a geographically restricted species in north-east Queensland, Orchadian, 11, 106

Bartareau, 1995, Pollination limitation, cost of reproduction and capsule-to-flower ratio in Dendrobium monophyllum F. Muell (Orchidaceae), Australian Journal of Ecology, 20, 257, 10.1111/j.1442-9993.1995.tb00537.x

Bateman, 1948, Intrasexual selection in Drosophila, Heredity, 2, 349, 10.1038/hdy.1948.21

Batty, 2001, Constraints to symbiotic germination of terrestrial orchid seed in a Mediterranean bushland, New Phytologist, 152, 511, 10.1046/j.0028-646X.2001.00277.x

Bawa, 1981, Evolution of sexual systems in flowering plants, Annals of the Missouri Botanical Garden, 68, 254, 10.2307/2398798

Bawa, 1984, Flower, fruit and seed abortion in tropical forest trees: implications for the evolution of paternal and maternal reproductive patterns, American Journal of Botany, 71, 736, 10.1002/j.1537-2197.1984.tb14181.x

Beardsell, 1986, Pollination of Diuris maculata R. Br. (Orchidaceae) by floral mimicry of the native legumes Daviesa spp. and Pultenaea scabra R. Br, Australian Journal of Botany, 34, 165, 10.1071/BT9860165

Bell, 1985, On the function of flowers, Proceedings of the Royal Society of London B, 224, 223, 10.1098/rspb.1985.0031

Benzing, 1987, Orchid biology, Vol. IV, 34

Bergström, 1992, Floral fragrance disparity between three taxa of Lady's Slipper Cypripedium calceolus (Orchidaceae), Phytochemistry, 31, 2315, 10.1016/0031-9422(92)83271-Y

Bernhardt, 1986, Observations of the floral biology of Prasophylum odoratum (Orchidaceae, Spiranthoideae), Plant Systematics and Evolution, 153, 65, 10.1007/BF00989418

Berry, 1991, Pollinator limitation and position-dependent fruit set in the high Andean orchid Myrosmodes  cochleare, Plant  Systematics  and  Evolution, 174, 93, 10.1007/BF00937697

Best, 1982, Pollinator foraging on foxglove (Digitalis purpurea): a test for a new model, Evolution, 36, 70

Bierzychudek, 1981a, Pollinator limitation of plant reproductive effort, American Naturalist, 117, 838, 10.1086/283773

Bierzychudek, 1981b, Asclepias, Lantana and Epidendrum: a floral mimicry complex?, Biotropica, 13, 54, 10.2307/2388070

Bino, 1982, The pollination ecology of Orchis galilaea (Bornm. et Schulze) Schltr. (Orchidaceae), New Phytologist, 90, 315, 10.1111/j.1469-8137.1982.tb03263.x

Blivona, 2002, A northernmost population of Cypripedium calceolus L. (Orchidaceae): demography, flowering, and pollination, Selbyana, 23, 111

Bohomak, 1999, Dispersal, gene flow, and population structure, Quarterly Review of Biology, 74, 21, 10.1086/392950

Boland, 1991, Ecological aspects of Arethusa bulbosa, Calopogon tuberosus, and Pogonia ophioglossoides (Orchidaceae) in eastern Newfoundland. I. Flowering and fruiting patterns, Rhodora, 93, 248

Bookman, 1984, Evidence for selective fruit production in Asclepias, Evolution, 38, 72, 10.1111/j.1558-5646.1984.tb00261.x

Borba, 2001, Fly-pollinated Pleurothallis (Orchidaceae) species have high genetic variability: evidence from isozyme markers, American Journal of Botany, 88, 419, 10.2307/2657106

Borba, 1998, Wind-assisted fly pollination in three Bulbophyllum (Orchidaceae) species occurring in Brazilian campos rupestres, Lindleyana, 13, 203

Borba, 1999a, Temporal variation in pollinarium size after its removal in species of Bulbophyllum: a different mechanism preventing self-pollination in Orchidaceae, Plant Systematics and Evolution, 217, 197, 10.1007/BF00984365

Borba, 1999b, Reproductive systems and crossing potential in three species of Bulbophyllum (Orchidaceae) occurring in Brazilian ‘campo rupestre’ vegetation, Plant Systematics and Evolution, 217, 205, 10.1007/BF00984366

Borba, 2001, Pollinator specificity and convergence in fly-pollinated Pleurothallis (Orchidaceae) species: a multiple population approach, Annals of Botany, 88, 75, 10.1006/anbo.2001.1434

Borba, 2001, Self-incompatibility, inbreeding depression and crossing potential in five Brazilian Pleurothallis (Orchidaceae) species, Annals of Botany, 88, 89, 10.1006/anbo.2001.1435

Borba, 1999, Reproductive systems and crossing potential in three species of Bulbophyllum (Orchidaceae) occurring in Brazilian ‘campo rupestre’ vegetation, Plant Systematics and Evolution, 217, 205, 10.1007/BF00984366

Borg-Karlson, 1987, Chemical basis for the relationship between Ophrys orchids and their pollinators, Chemica Scripta, 27, 303

Boyden, 1982, The pollination biology of Calypso bulbosa var. americana (Orchidaceae): initial deception of bumblebee visitors, Oecologia, 55, 178, 10.1007/BF00384485

Braem, 1988, The chromosome numbers of the taxa usually referred to as ‘variegata oncidiums’ (genera Braasiella, Hispaniella, Olgasis and Tolumnia) with a review of the chromosome numbers of the Orchidaceae and special reference to the Oncidiinae, Schlechteriana, 1, 23

Braga, 1977, Aspectos biológicos das Orchidaceae de uma campina de Amazonica Central, Acta Amazonica, 2, 1

Brzosko, 2002, Allozyme differentiation and genetic structure of the Lady's slipper (Cypripedium calceolus) island populations in north-east Poland, Botanical Journal of the Linnean Society, 138, 433, 10.1046/j.1095-8339.2002.00036.x

Brzosko, 2002, Spatial genetic structure and clonal diversity of island populations of lady's slipper (Cypripedium calceolus) from the Biebrza National Park (northeast Poland), Molecular Ecology, 11, 2449, 10.1046/j.1365-294X.2002.01630.x

Brzosko, 2003, Genetic variation and clonal diversity in island Cephalanthera rubra populations from Biebrza National Park, Poland, Botanical Journal of the Linnean Society, 143, 99, 10.1046/j.1095-8339.2003.00201.x

Bullini, 2001, Molecular evidence for allopolyploid speciation and a single origin of the western Mediterranean orchid Dactylorhiza insularis (Orchidaceae), Biological Journal of the Linnean Society, 72, 193, 10.1111/j.1095-8312.2001.tb01311.x

Burd, 1994, Bateman's Principle and plant reproduction: The role of pollen limitation in fruit and seed set, Botanical Review, 60, 63, 10.1007/BF02856594

Burdon, 1987., Diseases and plant population biology

Bush, 1999, RAPD variation in temperate populations of epiphytic orchid Epiendrum conopseum and the epiphytic fern Pleopelti polypodioides, Selbyana, 20, 120

Calder, 1982, Pollination ’82, 184

Calvo, 1990a, Four-year growth and reproduction of Cyclopogon cranichoides (Orchidaceae) in South Florida, American Journal of Botany, 77, 736, 10.1002/j.1537-2197.1990.tb14463.x

Calvo, 1990b, Inflorescence size and fruit distribution among individuals of three orchid species, American Journal of Botany, 77, 1378, 10.1002/j.1537-2197.1990.tb11389.x

Calvo, 1993, Evolutionary demography of orchids: intensity and frequency of pollination and the cost of fruiting, Ecology, 74, 1033, 10.2307/1940473

Calvo, 1990, Pollinator limitation, cost of reproduction, and fitness in plants: a transition matrix demographic approach, American Naturalist, 136, 499, 10.1086/285110

Campbell, 1989, Inflorescence size: test of the male function hypothesis, American Journal of Botany, 76, 730, 10.1002/j.1537-2197.1989.tb11367.x

Campbell, 1997, Analyzing pollinator-mediated selection in plant hybrid zone: hummingbird visitation patterns on three spatial scales, American Naturalist, 149, 295, 10.1086/285991

Carey, 1998, Modelling the spread of Himantoglossum hircinum (L.) Spreng. at a site in the north of England, Botanical Journal of the Linnean Society, 126, 159

Carroll, 1984, Status of 4 orchid species at Silver Lake Fen complex, Proceedings of the Iowa Academy of Science, 91, 132

Carson, 1990, Increased genetic variance after a population bottleneck, Trends in Ecology and Evolution, 5, 228, 10.1016/0169-5347(90)90137-3

Carvalho, 2002, Pollination of Catasetum macrocarpum (Orchidaceae) by Eulaema bombiformis (Euglossini), Lindleyana, 17, 85

Case, 1993, High levels of allozyme variation within Cypripedium calceolus (Orchidaceae) and low levels of divergence among its varieties, Systematic Botany, 18, 663, 10.2307/2419540

Case, 1994, Extensive variation in the levels of genetic diversity and degree of relatedness among five species of Cypripedium (Orchidaceae), American Journal of Botany, 81, 175, 10.1002/j.1537-2197.1994.tb15427.x

Case MA 2002 Evolutionary patterns in Cypripedium : Inferences from allozyme analyses Proceedings of the 16th World Orchid Conference, April 1999 . 192 202

Case, 1998, Conservation genetics and taxonomic status of the rare Kentucky Lady's slipper: Cypripedium kentuckiense (Orchidaceae), American Journal of Botany, 85, 1779, 10.2307/2446512

Catling, 1980, Rain-assisted autogamy in Liparis loeselii (L.) L. C. Rich (Orchidaceae), Bulletin of the Torrey Botanical Club, 107, 55, 10.2307/2484083

Catling, 1982, Breeding systems of northeastern North American Spiranthes (Orchidaceae), Canadian Journal of Botany, 60, 3017, 10.1139/b82-358

Catling, 1983a, Pollination of northeastern North American Spiranthes (Orchidaceae), Canadian Journal of Botany, 61, 1080, 10.1139/b83-116

Catling, 1983b, Autogamy in eastern Canadian Orchidaceae: a review of current knowledge and some new observations, Naturaliste Canadien, 110, 37

Catling, 1987, Notes on the breeding systems of Sacoila lanceolata (Aublet) Garay, Annals of the Missouri Botanical Gardens, 74, 58, 10.2307/2399262

Catling, 1990, Orchid biology: reviews and perspectives, 121

Charlesworth, 1979, The evolutionary genetics of sexual systems in flowering plants, Proceedings of the Royal Society of London B, 205, 511, 10.1098/rspb.1979.0082

Charlesworth, 1987, Inbreeding depression and its evolutionary consequences, Annual Review of Ecology and Systematics, 18, 237, 10.1146/annurev.es.18.110187.001321

Charnov, 1979, Simultaneous hermaphroditism and sexual selection, Proceedings of the National Academy of Sciences, USA, 76, 2480, 10.1073/pnas.76.5.2480

Charnov, 1982., The theory of sex allocation

Chase, 1986, Pollination ecology of two sympatric, synchronously flowering species of Leochilus in Costa Rica, Lindleyana, 1, 141

Chase, 1997, Molecular evolution and adaptive radiation, 331

Christensen, 1992, Notes on the reproductive biology of Stelis argentata Lindl. (Orchidaceae: Pleurothallidinae) in Eastern Ecuador, Lindleyana, 7, 28

Chung, 1999, Allozyme diversity and population structure in Korean populations of Cymbidium goeringii (Orchidaceae), Journal of Plant Research, 112, 139, 10.1007/PL00013868

Chung, 2003, The breeding systems of Cremastra appendiculata and Cymbidium goeringii: high levels of annual fruit failure in two self-compatible orchids, Annales Botanici Fennici, 40, 81

Chung, 2004, Spatial genetic structure in populations of the terrestrial orchid Cephalanthera longibracteata (Orchidaceae), American Journal of Botany, 91, 52, 10.3732/ajb.91.1.52

Van Der Cingel, 1995., An atlas of orchid pollinations: European orchids.

Cole, 1984, The floral ecology of Platanthera blephariglottis, American Journal of Botany, 71, 700, 10.1002/j.1537-2197.1984.tb14177.x

Coleman, 1995., The wild orchids of California

Corrias, 1991, Orchis longicornu Poiret in Sardinia: genetic, morphological and chronological data, Webbia, 45, 71, 10.1080/00837792.1991.10670491

Coyne, 1997, Perspectives: a critique of Sewall Wright's shifting balance theory of evolution, Evolution, 51, 643, 10.1111/j.1558-5646.1997.tb03650.x

Cropper, 1990, The floral biology of Thelymitra epipactoides (Orchidaceae), and the implications of pollination by deceit on the survival of this rare orchid, Plant Systematics and Evolution, 170, 11, 10.1007/BF00937846

Cropper, 1989, Thelymitra epipactoides F. Muell. (Orchidaceae), the morphology, biology and conservation of an endangered species, Proceedings of the Royal Society of Victoria, 101, 89

Crow, 1990, Phase three of Wright's shifting-balance theory, Evolution, 44, 233, 10.1111/j.1558-5646.1990.tb05194.x

Curtis, 1954, Annual fluctuations in rate of flower production by native Cypripedium during two decades, Bulletin of the Torrey Botanical Club, 81, 340, 10.2307/2997149

Dafni, 1983, Pollination of Orchis caspia -a nectarless plant which deceives the pollinators of nectariferous species from other plant families, Journal of Ecology, 71, 467, 10.2307/2259728

Dafni, 1984, Mimicry and deception in pollination, Annual Review of Ecology and Systematics, 15, 259, 10.1146/annurev.es.15.110184.001355

Dafni, 1987, Orchid biology: reviews and perspectives, 79

Dafni, 1987, Pollination by deceit and floral mimesis in Thelymitra antennifera (Orchidaceae), Plant Systematics and Evolution, 158, 11, 10.1007/BF00936140

Dafni, 1979, Pollination ecology of, and hybridization between, Orchis coriophora L. and O. collina Sol. ex Russ (Orchidaceae) in Israel, New Phytologist, 83, 181, 10.1111/j.1469-8137.1979.tb00740.x

Dafni, 1981a, Floral mimicry between Orchis israelitica Baumann and Dafni (Orchidaceae) and Bellevalia flexuosa Boiss. (Liliaceae), Oecologia, 49, 229, 10.1007/BF00349193

Dafni, 1981b, The flower biology of Cephalanthera longifolia (Orchidaceae) - Pollen imitation and facultative floral mimicry, Plant Systematics and Evolution, 137, 229, 10.1007/BF00982788

Dafni, 1981, Pollination of Serapias vomeracea Briq. (Orchidaceae) by imitation of holes for sleeping solitary male bees (Hymenoptera), Acta Botanica Neerlandica, 30, 69, 10.1111/j.1438-8677.1981.tb00388.x

Dafni, 1986, Stigmatic exudate and the pollination of Dactylorhiza fuchsii (Druce) Soo, Flora, 178, 343, 10.1016/S0367-2530(17)31521-9

Darwin, 1859., The origin of species by means of natural selection or the preservation of favoured races in the struggle for life

Darwin, 1871., The descent of man and selection in relation to sex

Darwin, 1877., The various contrivances by which orchids are fertilized by insects

Davies, 2000, Pseudopollen: its structure and development in Maxillaria (Orchidaceae), Annals of Botany, 85, 887, 10.1006/anbo.2000.1154

Davis, 1986, The pollination biology of Cypripedium acaule (Orchidaceae), Rhodora, 88, 445

Dieringer, 1982, The pollination ecology of Orchis spectabilis L. (Orchidaceae), Ohio Journal of Science, 82, 218

Dijk, 1997, Nutrient responses as a key factor to the ecology of orchid species, Acta Botanica Neerlandica, 46, 339, 10.1111/plb.1997.46.4.339

Dodson, 1962, The importance of pollination in the evolution of the orchids of tropical America, American Orchid Society Bulletin, 31, 525

Dodson, 1965, Studies in orchid pollination. The genus Coryanthes, American Orchid Society Bulletin, 34, 680

Dodson, 1969, Biologically active compounds in orchid fragrances, Science, 164, 1243, 10.1126/science.164.3885.1243

Dodson, 1961, Natural pollination of orchids, Missouri Botanical Gardens Bulletin, 49, 133

Donaldson, 2002, Effects of habitat fragmentation on pollinator activity and plant reproductive success in renosterveld shrublands of South Africa, Conservation Biology, 16, 1267, 10.1046/j.1523-1739.2002.99515.x

Dondon, 2002, A química das recompensas florais de Maxillarieae (Orchidaceae), 25a Reunião Anual da Sociedade Brasileira de Química

Dressler, 1968, Observations on orchids and euglossine bees in Panama and Costa Rica, Revista de Biologia Tropical, 15, 143

Dressler, 1981., The orchids: their natural history and classification

Dressler, 1982, Biology of the orchid bees (Euglossini), Annual Review of Ecology and Systematics, 13, 373, 10.1146/annurev.es.13.110182.002105

Dudash, 1990, Relative fitness of selfed and outcross progeny in a self-compatible, protandrous species, Sabatia angularis L. (Gentianaceae). A comparison in three environments, Evolution, 44, 1129, 10.1111/j.1558-5646.1990.tb05220.x

Duncan, 1943, Growth of fruits in Cattleya and allied genera in the Orchidaceae, Bulletin of the Torrey Botanical Club, 70, 104, 10.2307/2481362

East, 1940, The distribution of self-fertility in flowering plants, Proceedings of the American Philosophical Society, 82, 449

Ellis, 1999, Do pollinators determine hybridization patterns in sympatric Satyrium (Orchidaceae) species?, Plant Systematics and Evolution, 219, 137, 10.1007/BF00985575

Eltz, 1999, Fragrance collection, storage, and accumulation by individual male orchid bees, Journal of Chemical Ecology, 25, 157, 10.1023/A:1020897302355

Endler, 1986., Natural selection in the wild

Farrell, 1985, Orchis militaris L. (Biological Flora of the British Isles, 160), Journal of Ecology, 73, 1041, 10.2307/2260166

Firmage, 1988, Reproductive success and inflorescence size of Calopogon tuberosus (Orchidaceae), American Journal of Botany, 75, 1371, 10.1002/j.1537-2197.1988.tb14198.x

Fisher, 1992, Facultative ant association benefits a Neotropical orchid, Journal of Tropical Ecology, 8, 109, 10.1017/S0266467400006179

Folsom, 1994, Pollination of a fragrant orchid, Orchid Digest, 58, 83

Freudenstein, 1997, Sectile pollinia and relationships in Orchidaceae, Plant Systematics and Evolution, 205, 125, 10.1007/BF01464400

Fritz, 1990, Deceit pollination of Orchis spitzelii (Orchidaceae) on the island of Gotland in the Baltic: a suboptimal system, Nordic Journal of Botany, 9, 577, 10.1111/j.1756-1051.1990.tb00548.x

Fritz, 1994, How pollinator-mediated mating varies with population size in plants, Oecologia, 100, 451, 10.1007/BF00317867

Garwood, 1985, Factors limiting fruit and seed production of a temperate shrub, Staphylea trifolia L. (Staphyleaceae), American Journal of Botany, 72, 453, 10.1002/j.1537-2197.1985.tb05369.x

Gaut, 1996, Substitution rate comparisons between grasses and palms: synonymous rate differences at the nuclear gene Adh parallel rate differences at the plastid gene rbcL, Proceedings of the National Academy of Sciences, USA, 93, 10274, 10.1073/pnas.93.19.10274

Gigord, 2001, Negative frequency-dependent selection maintains a dramatic flower color polymorphism in the rewardless orchid Dactylorhiza sambicina (L.) Soò, Proceedings of the National Academy of Sciences, USA, 98, 6253, 10.1073/pnas.111162598

Gill, 1989, Speciation and its consequences, 458

Gill DE 1996 The natural population ecology of temperate terrestrials: Pink Lady's Slipper, Cypripedium acaule Allen C North American native terrestrial orchids: propagation and production. 91 106

Gillman, 2000, Detection of delayed density dependence in an orchid population, Journal of Ecology, 88, 204, 10.1046/j.1365-2745.2000.00440.x

González-Díaz, 1988, Pollination, fruit set, and seed production in the orchid, Oeceoclades maculata, Lindleyana, 3, 150

Goss, 1977, The reproductive biology of the epiphytic orchids of Florida. 6. Polystachya flavescens (Lindley), American Orchid Society Bulletin, 46, 990

Gregg, 1983, Variation in floral fragrances and morphology: incipient speciation in Cycnoches?, Botanical Gazette, 144, 566, 10.1086/337412

Gregg, 1989, Reproductive biology of the orchid Cleistes divaricata (L.) Ames var. bifaria Fernald growing in a West Virginia meadow, Castanea, 54, 57

Gregg, 1990, North American native terrestrial orchid propagation and production

Gregg, 1991a, Reproductive strategy of Cleistes divaricata (Orchidaceae), American Journal of Botany, 78, 350, 10.1002/j.1537-2197.1991.tb15197.x

Gregg, 1991b, Population ecology of terrestrial orchids, 139

Gregg, 1991c, Defrauding the deceitful orchid: pollen collection by pollinators of Cleites divericata and C. bifaria, Lindleyana, 6, 214

Gumbert, 2001, Colour similarity to rewarding model plants affects pollination in a food deceptive orchid, Orchid boryi, Biological Journal of the Linnean Society, 72, 419, 10.1111/j.1095-8312.2001.tb01328.x

Gustafsson, 2000, Patterns of genetic variation in Gymnadenia conopsea, the fragrant orchid, Molecular Ecology, 9, 1863, 10.1046/j.1365-294x.2000.01086.x

Gustafsson, 2002, Genetic diversity in the rare orchid, Gymnadenia odoratissima and a comparison with the more common congener, G. conopsea, Conservation Genetics, 3, 225, 10.1023/A:1019969014333

Hagerup, 1952, Bud autogamy in some northern orchids, Phytomorphology, 2, 51

Hainsworth, 1985, Pollen limitation in a monocarpic species, Ipomopsis aggregata, Journal of Ecology, 73, 263, 10.2307/2259782

Handel, 1993, Thynnine wasps discriminate among heights when seeking mates: tests with a sexually deceptive orchid, Oecologia, 95, 241, 10.1007/BF00323496

Harper, 1977., Population biology of plants

Harris, 1997, Isozyme analysis of the reported origin of a new hybrid orchid species, Epipactis youngiana (Young's helleborine), in the British Isles, Heredity, 79, 402, 10.1038/hdy.1997.174

Hartl, 1989., Principles of population genetics

Hedrén, 1996, Genetic differentiation, polyploidization and hybridization in northern European Dactylorhiza (Orchidaceae): evidence from allozyme markers, Plant Systematics and Evolution, 201, 31, 10.1007/BF00989050

Hedrén, 2000, Evolution of polyploids in the European orchid genus Nigritella: Evidence from allozyme data, Phyton, 40, 239

Heinrich, 1975, Bee flowers: a hypothesis on flower variety and blooming times, Evolution, 29, 325, 10.1111/j.1558-5646.1975.tb00212.x

Hernández-Apolinar M 1992. Laelia speciosa Tesis Titalode Biologo, Universidad Nacional Autonoma de México, México.

Hessing, 1988, Geitonogamous pollination and its consequences in Geranium caespitosum, American Journal of Botany, 75, 1324, 10.1002/j.1537-2197.1988.tb14193.x

Hills, 1972, Floral fragrances and isolating mechanisms in the genus Catasetum (Orchidaceae), Biotropica, 4, 61, 10.2307/2989728

Hogan, 1983, The pollination biology and breeding system of Aplectrum hyemale (Orchidaceae), Canadian Journal of Botany, 61, 1906, 10.1139/b83-202

Hollingsworth, 1997, Genetic variation in rural and urban populations of Epipactis helleborine (L.) Crantz. (Orchidaceae) in Britain, Botanical Journal of the Linnean Society, 123, 321

Holsinger, 1988, The evolution of self-fertilization in plants: lessons from population genetics, Acta Oecologica: Serie Oecologica Plantarum, 9, 95

Iannotti, 1987, O sistema reproductivo de Epidendrum rigidum Jacq. (Orchidaceae), Ciencia y Cultura, 39, 641

Iman, 1974, A power study of a rank transform for the two-way classification model when interaction may be present, Canadian Journal of Statistics, 2, 227, 10.2307/3314695

Inoue, 1985, Reproductive biology of two platantherans (Orchidaceae) in the island of Hachijo, Japanese Journal of Ecology, 35, 77

Inoue, 1986a, Different effects of sphingid and noctuid moths on the fecundity of Platanthera metabifolia (Orchidaceae) in Hokkaido, Ecological Research, 1, 25, 10.1007/BF02361202

Inoue, 1986b, Experimental studies on male and female reproductive success: effects of variation in spur length and pollinator activity on Platanthera mandarinorum ssp. Hachijoensis (Orchidaceae), Plant Species Biology, 1, 207, 10.1111/j.1442-1984.1986.tb00028.x

Ivri, 1977, The pollination ecology of Epipactis consimilis Don (Orchidaceae) in Israel, New Phytologist, 79, 173, 10.1111/j.1469-8137.1977.tb02193.x

Jain, 1976, The evolution of inbreeding in plants, Annual Review of Ecology and Systematics, 7, 469, 10.1146/annurev.es.07.110176.002345

Janzen, 1971, Euglossine bees as long-distance pollinators of tropical plants, Science, 171, 1440, 10.1126/science.171.3967.203

Janzen, 1977, A note on optimal mate selection by plants, American Naturalist, 111, 365, 10.1086/283166

Janzen, 1980, Self- and cross- pollination of Encyclia cordigera (Orchidaceae) in Santa Rosa National Park, Costa Rica, Biotropica, 12, 72, 10.2307/2387776

Johansen, 1990, Incompatibility in Dendrobium (Orchidaceae), Botanical Journal of the Linnean Society, 103, 165, 10.1111/j.1095-8339.1990.tb00183.x

Johnson, 1993, Carpenter bee pollination of Herschelianthe graminifolia (Orchidaceae) on the Cape Peninsula, Flora, 188, 383, 10.1016/S0367-2530(17)32288-0

Johnson, 1994, Evidence for Batesian mimicry in a butterfly-pollinated orchid, Biological Journal of the Linnean Society, 53, 91, 10.1111/j.1095-8312.1994.tb01003.x

Johnson, 1995, Moth pollination of the cryptic Cape orchid Monadenia ophrydea, Flora, 190, 105, 10.1016/S0367-2530(17)30638-2

Johnson, 1992, Habitat dependent pollination success in a Cape Orchid, Oecologia, 91, 455, 10.1007/BF00317637

Johnson, 2000, The structure and function of orchid pollinaria, Plant Systematics and Evolution, 222, 243, 10.1007/BF00984105

Johnson, 1998, Phylogeny and radiation of pollination systems in Disa (Orchidaceae), American Journal of Botany, 85, 402, 10.2307/2446333

Johnson, 1999, Pollen carryover, geitonogamy, and the evolution of deceptive pollination systems in orchids, Ecology, 80, 2607, 10.1890/0012-9658(1999)080[2607:PCGATE]2.0.CO;2

Johnson, 1994, Pollination by megachilid bees and determinants of fruit-set in the Cape orchid Disa tenuifolia, Nordic Journal of Botany, 14, 481, 10.1111/j.1756-1051.1994.tb00637.x

Johnson, 1994, Auto-pollination in Disa species (Orchidaceae) of the Cape mountain cloud zone, Lindleyana, 9, 3

Johnson, 1998, Pollination ecology and maintenance of species integrity in co-occurring Disa racemosa L. f. and Disa venosa Sw. (Orchidaceae) in South Africa, Annals of the Missouri Botanical Garden, 85, 231, 10.2307/2992007

Kallunki, 1976, Population studies in Goodyera (Orchidaceae) with emphasis on the hybrid origin of G. tesselata, Brittonia, 28, 53, 10.2307/2805559

Kallunki, 1981, Reproductive biology of mixed-species populations of Goodyera (Orchidaceae) in northern Michigan, Brittonia, 33, 137, 10.2307/2806308

Kimsey, 1982., Systematics of the bees of the genus Eufriesia (Hymenoptera, Apidae)

Kimura, 1965, Attainment of quasi-linkage equilibrium when gene frequencies are changing by natural selection, Genetics, 52, 875, 10.1093/genetics/52.5.875

Kimura, 1963, The measurement of effective population number, Evolution, 17, 279, 10.1111/j.1558-5646.1963.tb03281.x

Kindlmann, 2001, Irregular flowering patterns in terrestrial orchids: theories vs empirical data, Web Ecology, 2, 75, 10.5194/we-2-75-2001

Kipping JL 1971. Pollination studies of native orchids MA Thesis.

Kirchner, 1922a, Uber Selbstbestaubung bei den Orchidaceen, Flora, 115, 103

Kirchner, 1922b, Zur Selbstbestaubung der Orchidaceen, Berichte der Deutschen Botanischen Gesellschaft, 40, 317, 10.1111/j.1438-8677.1922.tb07986.x

Kisseleva, 2001, Orchis militaris in south-west Mordovia, Botanicheskii Zhurnal St-Petersburg, 86, 72

Kjellsson, 1985, Pollination of Dendrobium infundibulum, Cymbidium insigne (Orchidaceae), and Rhododendron lyi (Ericaceae) by Bombus eximius (Apidae) in Thailand: a possible case of floral mimicry, Journal of Tropical Ecology, 1, 289, 10.1017/S0266467400000389

Klinkhamer, 1993, Attractiveness to pollinators: a plant's dilemma, Oikos, 66, 180, 10.2307/3545212

Kocyan, 2001, Floral structure and development of Apostasia and Neuwiedia (Apostasioideae) and their relationships to other Orchidaceae, International Journal of Plant Science, 162, 847, 10.1086/320781

Koivisto, 2002, Pollination and reproductive success of two colour variants of a deceptive orchid, Dactylorhiza maculata (Orchidaceae), Nordic Journal of Botany, 22, 53, 10.1111/j.1756-1051.2002.tb01621.x

Koopowitz, 1998, Postpollination nectar reabsorption in the African epiphyte Aerangis verdickii (Orchidaceae), American Journal of Botany, 85, 508, 10.2307/2446434

Koryan, 2001, Floral structure and development of Apostasia and Neuwiedia (Apostasioideae) and their relationships to other Orchidaceae, International Journal of Plant Science, 162, 847, 10.1086/320781

Kull, 1998, Fruit-set and recruitment in populations of Cypripedium calceolus L. in Estonia, Botanical Journal of the Linnean Society, 126, 27

Kull, 1991, Population ecology of terrestrial orchids, 69

Kunze, 2001, The combined effect of color and odor on flower choice behavior of bumble bees in flower mimicry systems, Behavioral Ecology, 12, 447, 10.1093/beheco/12.4.447

Lammi, 1995, Deceptive pollination of Dactylorhiza incarnata: an experimental test of the magnet species hypothesis, Oecologia, 101, 500, 10.1007/BF00329430

Lande, 1975, The maintenance of genetic variability by mutation in a polygenic character with linked loci, Genetical Research, 26, 221, 10.1017/S0016672300016037

Lande, 1979, Quantitative genetic analysis of multivariate evolution, applied to brain-body size allometry, Evolution, 33, 402

Lande, 1983, The measurement of selection on correlated characters, Evolution, 37, 1210, 10.1111/j.1558-5646.1983.tb00236.x

Lande, 1985, The evolution of self-fertilization and inbreeding depression in plants I. Genetic models, Evolution, 39, 24, 10.1111/j.1558-5646.1985.tb04077.x

Larson, 1987, Observations on the pollination biology of Spiranthes romanzoffiana, Lindleyana, 2, 176

Lee, 1988, Plant reproductive ecology, 179

Lee, 1982, Regulation of fruit and seed production in an annual legume, Cassia fasciculata, Ecology, 63, 1363, 10.2307/1938864

Leeson, 1991, Population ecology of terrestrial orchids, 125

Lehnebach, 2003, Pollination biology of the Chilean endemic orchid Chloraea lamellata, Biodiversity and Conservation, 12, 1741, 10.1023/A:1023666800948

Li, 2002, A preliminary study on conservation genetics of an endangered orchid (Paphiopedilum micranthum) from Southwestern China, Biochemical Genetics, 40, 195, 10.1023/A:1015888226416

Lipow, 2002, Comparative rates of pollination and fruit set in widely separated populations of a rare orchid (Cypripedium fasciculatum), International Journal of Plant Science, 163, 775, 10.1086/342083

Lloyd, 1980, Sexual strategies in plants. I. A hypothesis of serial adjustment of maternal investment during one reproductive session, New Phytologist, 86, 81, 10.1111/j.1469-8137.1980.tb00781.x

Luyt, 2001, Hawkmoth pollination of the African epiphytic orchid Mystacicium venosum, with reference to flower and pollen longevity, Plant Systematics and Evolution, 228, 49, 10.1007/s006060170036

Luyt, 2002, Postpollination nectar reabsorption and its implications for fruit quality in an epiphytic orchid, Biotropica, 34, 442, 10.1111/j.1744-7429.2002.tb00558.x

Maad, 2000, Phenotypic selection in hawkmoth-pollinated Platanthera bifolia: targets and fitness surfaces, Evolution, 54, 112

Malo, 2001, Population fragmentation, floviry, and the effects of flower morphology alterations on the pollination success of Myrmecophila tibicinis (Orchidaceae), Biotropica, 33, 529, 10.1111/j.1744-7429.2001.tb00207.x

Mant, 2002, A phylogenetic study of pollinator conservatism among sexually deceptive orchids, Evolution, 56, 888, 10.1111/j.0014-3820.2002.tb01402.x

Marshall, 1986, Sexual selection in Raphanus sativus: experimental data on nonrandom fertilization, maternal choice, and consequences of multiple paternity, American Naturalist, 127, 446, 10.1086/284494

Matsui, 2001, Pollination limitation in a deceptive orchid, Pogonia japonica, on a floating peat mat, Plant Species Biology, 16, 231, 10.1046/j.1442-1984.2001.00067.x

Mattila, 2000, The effects of water stress and pollen availability on reproductive success of Platanthers bifolia (Orchidaceae), Avhandlinger Utgitt av det Norske Videnskaps-Akademi i Oslo i Matematisk-Naturvidenskapelig Klasse, 39, 83

Mattila, 2000, Nutrient versus pollination limitation in Platanthera bifolia and Dactylorhiza incarnata (Orchidaceae), Oikos, 89, 360, 10.1034/j.1600-0706.2000.890217.x

McKendrick, 2002, Symbiotic germination and development of the myco-heterotrophic orchid Neottia nidus-avis in nature and its requirement for locally distributed Sebacina spp, New Phytologist, 154, 233, 10.1046/j.1469-8137.2002.00372.x

Mehrhoff, 1983, Pollination in the genus Isotria (Orchidaceae), American Journal of Botany, 70, 1444, 10.1002/j.1537-2197.1983.tb10847.x

Meléndez, 1993, The effects of a rust infection on fitness components in a natural population of Tolumnia variegata (Orchidaceae), Oecologia, 94, 361, 10.1007/BF00317110

Meléndez-Ackerman, 2001, Density-dependent variation in reproductive success in a terrestrial orchid, Plant Systematics and Evolution, 227, 27, 10.1007/s006060170054

Meléndez-Ackerman, 2000, Reproduction in an orchid is resource limited over its lifetime, Biotropica, 32, 282, 10.1111/j.1744-7429.2000.tb00471.x

Merrell, 1981., Ecological genetics

Montalvo, 1992, Relative success and outcross pollen comparing mixed and single-donor pollinations in Aquilegia caerulea, Evolution, 46, 1181

Montalvo, 1987, Limitations to fruit production in Ionopsis utricularioides, Biotropica, 19, 24, 10.2307/2388456

Moya, 1993, Variation in the floral fragrance of Epidendrum ciliare (Orchidaceae), Nordic Journal of Botany, 13, 41, 10.1111/j.1756-1051.1993.tb00009.x

Murren, 2002, Effects of habitat fragmentation on pollination: pollinators, pollinia viability and reproductive success, Journal of Ecology, 90, 100, 10.1046/j.0022-0477.2001.00638.x

Murren, 1996, Effects of habitat, plant size, and floral display on male and female reproductive success of the neotropical orchid Brassavola nodosa, Biotropica, 28, 30, 10.2307/2388769

Murren, 1998, Seed dispersal characteristics of Brassavola nodosa (Orchidaceae), American Journal of Botany, 85, 675, 10.2307/2446537

Nazarov CJ 1995. Reproductive biology of Crimean orchids PhD Thesis.

Nazarov, 1997, The potential seed productivity of orchid flowers and peculiarities of their pollination systems, Lindleyana, 12, 188

Neiland, 1998, Fruit set, nectar reward, and rarity in the Orchidaceae, American Journal of Botany, 85, 1657, 10.2307/2446499

Nielsen, 2000, Interspecific differentiation and hybridization in Vanilla species (Orchidaceae), Heredity, 83, 560, 10.1038/sj.hdy.6885880

Nilsson, 1978a, Pollination ecology of Epipactis palustris (Orchidaceae), Botaniska Notiser, 131, 355

Nilsson, 1978b, Pollination ecology and adaptation in Platanthera chlorantha (Orchidaceae), Botaniska Notiser, 131, 35

Nilsson, 1979a, The pollination ecology of Herminiun monorchis (Orchidaceae), Botaniska Notiser, 132, 537

Nilsson, 1979b, Anthecological studies on the lady's slipper, Cypripedium calceolus (Orchidaceae), Botaniska Notiser, 132, 329

Nilsson, 1980, The pollination ecology of Dactylorhiza sambucina (Orchidaceae), Botaniska Notiser, 133, 367

Nilsson, 1981, The pollination ecology of Listera ovata (Orchidaceae), Nordic Journal of Botany, 1, 461, 10.1111/j.1756-1051.1981.tb00711.x

Nilsson, 1983a, Processes of isolation and introgressive interplay between Platanthera bifolia (L.) Rich and P. chlorantha (Custer) Reichb. (Orchidaceae), Botanical Journal of the Linnean Society, 87, 325, 10.1111/j.1095-8339.1983.tb00997.x

Nilsson, 1983b, Anthecology of Orchis mascula (Orchidaceae), Nordic Journal of Botany, 3, 157, 10.1111/j.1756-1051.1983.tb01059.x

Nilsson, 1983c, Mimesis of bellflower (Campanula) by the red helleborine orchid Cephalanthera rubra, Nature, 305, 799, 10.1038/305799a0

Nilsson, 1984, Anthecology of Orchis morio (Orchidaceae) at its outpost in the north, Nova Acta Regiae Societatia Scientiarum Upsaliensia, 3, 167

Nilsson, 1985, Monophyly and pollination mechanisms in Angraecum arachnites Schltr. (Orchidaceae) in a guild of long-tongued hawk-moths (Sphingidae) in Madagascar, Biological Journal of the Linnean Society, 26, 1, 10.1111/j.1095-8312.1985.tb01549.x

Nilsson, 1988, The evolution of flowers with deep corolla tubes, Nature, 334, 147, 10.1038/334147a0

Nilsson, 1992, Orchid pollination biology, Trends in Ecology and Evolution, 7, 255, 10.1016/0169-5347(92)90170-G

Nilsson, 1985, Monophyly and pollination mechanism in Angraecum arachnites Schltr. (Orchidaceae) in a guild of long-tongued hawk-moths (Sphingidae) in Madagascar, Biological Journal of the Linnean Society, 26, 1, 10.1111/j.1095-8312.1985.tb01549.x

Nilsson, 1986, The pollination of Cymbidiella flabellata (Orchidaceae) in Madagascar: a system operated by sphecid wasps, Nordic Journal of Botany, 6, 411, 10.1111/j.1756-1051.1986.tb00897.x

Nilsson, 1987, Angrecoids and hawkmoths in Central Madagascar: specialized pollination systems and generalist foragers, Biotropica, 19, 310, 10.2307/2388628

Nilsson, 1988, Hawk-moth scale analysis and pollination specialization in the epilithic Malagasy endemic Aerangis ellisii (Reichenb. fil.) Schltr. (Orchidaceae), Botanical Journal of the Linnean Society, 97, 49, 10.1111/j.1095-8339.1988.tb01686.x

Nilsson, 1992, Exact tracking of pollen transfer and mating in plants, Nature, 360, 666, 10.1038/360666a0

Nilsson, 1992, Long pollinia on eyes: hawk-moth pollination of Cynorkis uniflora Lindley (Orchidaceae) in Madagascar, Botanical Journal of the Linnean Society, 109, 145, 10.1111/j.1095-8339.1992.tb00263.x

Nunney, 1993, The influence of mating system and overlapping generations on effective population size, Evolution, 47, 1329, 10.1111/j.1558-5646.1993.tb02158.x

Nunney, 2000, The limits to knowledge in conservation genetics: The value of effective population size, Evolutionary Biology, 32, 179, 10.1007/978-1-4615-4135-6_9

O'Connell, 1998, Male and female pollination success in a deceptive orchid, a selection study, Ecology, 79, 1246, 10.2307/176740

Oh, 2001, Contrasting breeding systems: Liparis kumokiri and L. makinoama (Orchidaceae), Annales Zoologici Fennici, 38, 281

Orive, 1993, Effective population size in organisms with complex life-histories, Theoretical Population Biology, 44, 316, 10.1006/tpbi.1993.1031

Ortiz-Barney, 1999, The cost of selfing in Encyclia cochleata (Orchidaceae), Plant Systematics and Evolution, 219, 55, 10.1007/BF01090299

Pacini, 2002, Types of pollen dispersal units in orchids, and their consequences for germination and fertilization, Annals of Botany, 89, 653, 10.1093/aob/mcf138

Parra-Tabla, 2000, Female and male pollination success of Oncidium ascendens Lind[1]ey sic. (Orchidaceae) in two contrasting habitat patches: forest vs. agricultural field, Biological Conservation, 94, 335, 10.1016/S0006-3207(99)00187-1

Patt, 1989, Pollination biology of Platanthera stricta (Orchidaceae) in Olympic National Park, Washington, American Journal of Botany, 76, 1097, 10.1002/j.1537-2197.1989.tb15093.x

Patt, 1988, Analysis of the floral fragrance of Plathanthera stricta, Phytochemistry, 27, 91, 10.1016/0031-9422(88)80596-X

Peakall, 1989a, The unique pollination of Leporella fimbriata (Orchidaceae): pollination by pseudocopulating male ants (Myrmecia urens, Formicidae), Plant Systematics and Evolution, 167, 137, 10.1007/BF00936402

Peakall, 1989b, A new technique for monitoring pollen flow in orchids, Oecologia, 79, 361, 10.1007/BF00384315

Peakall, 1990, Responses of male Zaspilothynnus trilobatus Turner wasps to females and the sexually deceptive orchid it pollinates, Functional Ecology, 4, 159, 10.2307/2389335

Peakall, 1989, Pollination of the orchid Microtis parviflora R. Br. by flightless worker ants, Functional Ecology, 3, 515, 10.2307/2389565

Peakall, 1996, Ecological and genetic consequences of pollination by sexual deception in the orchid Caladenia tentaculata, Ecology, 50, 2207

Peakall, 1987, Pseudocopulation of an orchid by male ants: a test of two hypotheses accounting for the rarity of ant pollination, Oecologia, 73, 522, 10.1007/BF00379410

Peakall, 1989, Outcrossing in an ant pollinated clonal orchid, Heredity, 62, 161, 10.1038/hdy.1989.24

Pedersen, 1995, Anthecological observations on Dendrochilum longibracteatum- a species pollinated by facultatively anthophilous insects, Lindleyana, 10, 19

Pettersson, 1989, Pollination in the African species of Nervilia (Orchidaceae), Lindleyana, 1, 33

Pettersson, 1983, Pollinationsekollogin hos Adam och Eva på Stora Karlsö, Svensk Botanisk Tidskrift, 77, 123

Pintaúdi, 1990, Polinizações naturais e artificiais de Xylobium squalens Lindl. (Orchidaceae), Naturalia, 15, 67

Piper, 1988, The gender role of flowers of broad leaved helleborine, Epipactis helleborine (L.) Crantz (Orchidaceae), Functional Ecology, 2, 35, 10.2307/2389457

Plepys, 2002, Volatiles from flowers of Platanthera bifolia (Orchidaceae) attractive to the silver Y moth, Autographa gamma (Lepidoptera: Noctuidae), Oikos, 99, 69, 10.1034/j.1600-0706.2002.990107.x

Pridgeon, 1999., Genera Orchidacearum, 1, 10.1093/oso/9780198505136.001.0001

Primack, 1990, Cost of reproduction in the pink lady's slipper orchid: a four year experimental study, American Naturalist, 136, 638, 10.1086/285120

Primack, 1994, Costs of reproduction in the pink lady's slipper orchid (Cypripedium acaule): defoliation, increased fruit production and fire, American Journal of Botany, 81, 1083, 10.1002/j.1537-2197.1994.tb15601.x

Proctor, 1998, Effect of pollen age on fruit set, fruit weight, and seed set in three orchid species, Canadian Journal of Botany, 76, 420, 10.1139/b98-010

Proctor, 1994, Pollen load, capsule weight, and seed production in three orchid species, Canadian Journal of Botany, 72, 249, 10.1139/b94-033

Proctor, 1995, Effect of pollination on floral longevity in the orchid Calypso bulbosa (Orchidaceae), American Journal of Botany, 82, 1131, 10.1002/j.1537-2197.1995.tb11584.x

Queller, 1985, Proximate and ultimate causes of low fruit production in Asclepias exaltata, Oikos, 44, 373, 10.2307/3565777

Quesnel, 1982, Life history of Cyrtopodium broadwayi, Trinidad Naturalist, 4, 34

Rasmussen, 2002, Phenology of roots and mycorrhiza in orchid species differing in phototrophic strategy, New Phytologist, 154, 797, 10.1046/j.1469-8137.2002.00422.x

Rico-Gray, 1989, An unusual animal-plant interaction: feeding of Schomburgkia tibicinis (Orchidaceae) by ants, American Journal of Botany, 76, 603, 10.1002/j.1537-2197.1989.tb11352.x

Rico-Gray, 1987, Some aspects of the reproductive biology of Schomburgkia tibicinis Batem. (Orchidaceae) in Yucatan, Mexico, Brenesia, 28, 13

Robertson, 1990, Evidence for pollination ecotypes in the yellow-fringed orchid, Platanthera ciliaris, Evolution, 44, 121, 10.1111/j.1558-5646.1990.tb04283.x

Rodríguez-Robles, 1992, Effects of display size, flowering phenology, and nectar availability on effective visitation frequencies in Comparettia falcata (Orchidaceae), American Journal of Botany, 79, 1009, 10.1002/j.1537-2197.1992.tb13690.x

Rossi, 1992, Gene variation and gene flow in Orchis morio (Orchidaceae) from Italy, Plant Systematics and Evolution, 179, 43, 10.1007/BF00938018

Roubik, 1987, Long-term ecology of euglossine orchid-bees (Apidae: Euglossini) in Panama, Oecologia, 73, 321, 10.1007/BF00385247

Roughgarden, 1996., Theory of population genetics and evolutionary ecology: an introduction

Sabat, 1996, Fruit set in a deceptive orchid: The effect of flowering phenology, display size, and local floral abundance, American Journal of Botany, 83, 1181, 10.1002/j.1537-2197.1996.tb13899.x

Salguero-Faría, 1999, A nectar reward: is more better?, Biotropica, 31, 303, 10.1111/j.1744-7429.1999.tb00142.x

Sazima, 1978, Polinização por moscas em Bulbophyllum warmingianum Cogn. (Orchidaceae), na Serra do Cipó, Minas Gerais, Brazil, Revista Brasileira de Botanica, 1, 133

Scacchi, 1989, Isoenzyme polymorphisms in Gymnaedenia[sic]conopsea and its inferences for systematics within this species, Biochemical Systematics and Ecology, 17, 25, 10.1016/0305-1978(89)90038-0

Scacchi, 1991, Effect of the breeding system on the genetic structure in Cephalanthera spp. (Orchidaceae), Plant Systematics and Evolution, 176, 53, 10.1007/BF00937945

Scacchi, 1990, Allozyme variation among and within eleven Orchis species (fam. Orchidaceae), with special reference to hybridizing aptitude, Genetica, 81, 143, 10.1007/BF00226453

Scacchi, 1987, Study of electrophoretic  variability  in  Epipactis  heleborine (L.)  Crantz, E. palustris (L.) Crantz and E. microphylla (Ehrh.) Swartz (fam. Orchidaceae), Genetica, 72, 217, 10.1007/BF00116226

Schemske, 1980, Evolution of floral display in the orchid Brassavola nodosa, Evolution, 34, 489, 10.1111/j.1558-5646.1980.tb04838.x

Schemske, 1988, Plant-animal interactions and fruit production in a neotropical herb: a path analysis, Ecology, 69, 1128, 10.2307/1941267

Schiestl, 2001, Post-pollination emission of a repellent compound in a sexually deceptive orchid: a new mechanism for maximizing reproductive success, Oecologia, 126, 531, 10.1007/s004420000552

Selosse, 2002, Communities and populations of sebacinoid basidiomycetes associated with achlorophyllous Neottia nidus-avis (L.) L.C.M. Rich. and neighbouring tree Ectomycorrhizae, Molecular Ecology, 11, 1831, 10.1046/j.1365-294X.2002.01553.x

Sharma, 2000, Observations of high genetic variability in the endangered Australian terrestrial orchid Pterostylis gibbossa R. Br. (Orchidaceae), Biochemical Systematics and Ecology, 28, 651, 10.1016/S0305-1978(99)00107-6

Sharma, 2003, Unusually high genetic variability revealed through allozymic polymorphism of an endemic and endangered Australian orchid, Pterostylis aff. picta, Biochemical Systematics and Ecology, 31, 513, 10.1016/S0305-1978(02)00186-2

Sharma, 2001, Genetic diversity and phylogenetic relatedness among six endemic Pterostylis species (Orchidaceae; Series Grandiflorae) of Western Australia, as revealed by allozyme polymorphisms, Biochemical Systematics and Ecology, 29, 697, 10.1016/S0305-1978(00)00112-5

Shiau, 2002, Conservation of Anoectochilus formosanus Hayata by artificial cross-pollination and in vitro culture of seeds, Botanical Bulletin of the Academia Sinica Taipei, 43, 123

Singer, 2001, Pollination biology of Habenaria parviflora (Orchidaceae: Habenariinae) in southeastern Brazil, Darwiniana, 39, 201

Singer, 2002, The pollination biology of Sauroglossum elatum Lindl. (Orchidaceae: Spiranthinae): moth-pollination and protandry in neotropical Spiranthinae, Botanical Journal of the Linnean Society, 138, 9, 10.1046/j.1095-8339.2002.00003.x

Singer, 1997a, Pollination of Pteroglossaspis ruwenzoriensis (Rendle) Rolfe (Orchidaceae) by beetles in Argentina, Botanica Acta, 110, 338, 10.1111/j.1438-8677.1997.tb00649.x

Singer, 1997b, Eye attached hemipollinaria in the hawkmoth and settling moth pollination of Habenaria (Orchidaceae). A study on functional morphology in five species from subtropical South America, Botanica Acta, 110, 328, 10.1111/j.1438-8677.1997.tb00648.x

Singer, 2002, Notes on the pollination biology of Notylia nemorosa (Orchidaceae): do pollinators necessarily promote cross pollination?, Journal of Plant Research, 116, 19, 10.1007/s10265-002-0064-4

Singer, 1999, The pollination mechanism in the ‘Pelexia alliance’ (Orchidaceae: Spiranthinae), Botanical Journal of the Linnean Society, 131, 249

Singer, 2000, The pollination of Stenorrhynchos lanceolatus (Aublet) L. C. Rich. (Orchidaceae: Spiranthinae) by hummingbirds in southeastern Brazil, Plant Systematics and Evolution, 223, 221, 10.1007/BF00985281

Singer, 2001a, The pollination mechanism of three sympatric Prescottia (Orchidaceae: Prescottinae) species in southeastern Brazil, Annals of Botany, 88, 999, 10.1006/anbo.2001.1535

Singer, 2001b, Flower morphology and pollination mechanism in three sympatric Goodyerinae orchids from southeastern Brazil, Annals of Botany, 88, 989, 10.1006/anbo.2001.1534

Slatkin, 1989, A comparison of three indirect methods for estimating average levels of gene flow, Evolution, 43, 1349, 10.1111/j.1558-5646.1989.tb02587.x

Smith, 2002, Genetic variation in the terrestrial orchid Tipularia discolor, Southeastern Naturalist, 1, 17, 10.1656/1528-7092(2002)001[0017:GVITTO]2.0.CO;2

Smith, 1976, Pollination ecology of Platanthera (Habenaria) ciliaris and P. blephariglottis (Orchidaceae), Botanical Gazette, 137, 133, 10.1086/336852

Smithson, 2001, Cognitive ecology of pollination: animal behavior and floral evolution, 237, 10.1017/CBO9780511542268.013

Smithson, 2002, The consequences of rewardlessness in orchids: Reward-supplementation experiments with Anacamptis morio (Orchidaceae), American Journal of Botany, 89, 1579, 10.3732/ajb.89.10.1579

Smithson, 2001, Are there fitness advantages in being a rewardless orchid? Reward supplementation experiments with Barlia robertiana, Proceedings of the Royal Society of London B, 268, 1435, 10.1098/rspb.2001.1705

Snow, 1989, Cost of flower and fruit production in Tipularia discolor, Ecology, 70, 1286, 10.2307/1938188

Soliva, 1999, Genetic and floral divergence among sympatric populations of Gymnadenia conopsea s.l. (Orchidaceae) with different flowering phenology, International Journal of Plant Science, 160, 897, 10.1086/314192

Sosa, 2000, Pollination and natural history of Mormodes tuxtlensis (Catasetinae: Orchidaceae), Lindleyana, 15, 53

Southwick, 1984, Photosynthate allocation to floral nectar: a neglected energy investment, Ecology, 65, 1775, 10.2307/1937773

Squirrell, 2001, Partitioning and diversity of nuclear and organelle markers in native and introduced populations of Epipactis helleborine (Orchidaceae), American Journal of Botany, 88, 1409, 10.2307/3558447

Stanton, 1986, Floral evolution: attractiveness to pollinators increases male fitness, Science, 232, 1625, 10.1126/science.232.4758.1625

Stebbins, 1959, The role of hybridization in evolution, Proceedings of the American Philosophical Society, 103, 231

Steiner, 1989, The pollination of Disperis (Orchidaceae) by oil-collecting bees in southern Africa, Lindleyana, 4, 164

Steiner, 1998, The evolution of beetle pollination in a South African orchid, American Journal of Botany, 85, 1180, 10.2307/2446351

Steiner, 1994, Floral and pollinator divergence in two sexually deceptive South Africa orchids, American Journal of Botany, 81, 185, 10.1002/j.1537-2197.1994.tb15428.x

Stephenson, 1980, Fruit set, herbivory, fruit reduction and the fruiting strategy of Catalpa speciosa (Bignoniaceae), Ecology, 61, 57, 10.2307/1937155

Stephenson, 1981, Flower and fruit abortion: proximate causes and ultimate functions, Annual Review of Ecology and Systematics, 12, 253, 10.1146/annurev.es.12.110181.001345

Stephenson, 1983, Pollination biology, 109, 10.1016/B978-0-12-583980-8.50013-2

Stephenson, 1986, Lotus corniculatus regulates offspring quality through selective fruit abortion, Evolution, 40, 453, 10.1111/j.1558-5646.1986.tb00498.x

Stern, 1988, The long-distance dispersal of Oeceoclades maculata, American Orchid Society Bulletin, 57, 960

Stort, 1973, Natural pollination in Cattleya loddigesii Lindl, American Orchid Society Bulletin, 42, 606

Stort, 1984, Self- and cross-pollination in some species of the genus Laelia Lindl. (Orchidaceae), Revista Brasileira de Genetica, VII, 671

Stort, 1986, Crossing systems in Epidendrum nocturnum Jacq. (Orchidaceae), Revista Biologia Tropical, 34, 59

Stort, 1980, Autopolinização e polinização cruzada em algumas espécies do género Cattleya (Orchidaceae), Ciencia y Cultura, 32, 1080

Sugiura, 1995, The pollination of Bletilla striata (Orchidaceae), Ecological Research (Tokyo), 10, 171, 10.1007/BF02347939

Sugiura, 1996a, Pollination biology of Cremastra appendiculata var. variabilis (Orchidaceae), Plant Species Biology, 11, 185, 10.1111/j.1442-1984.1996.tb00144.x

Sugiura, 1996b, Pollination of the orchid Epipactis thumbergi by syrphid flies (Diptera: Syrphidae), Ecological Research (Tokyo), 11, 249, 10.1007/BF02347782

Sugiura, 2001, Flowering phenology, pollination, and fruit set of Cypripedium macranthos var. rebunense, a threatened lady's slipper (Orchidaceae), Journal of Plant Research, 114, 171, 10.1007/PL00013980

Sugiura, 1997, A note on the pollination of Oreorchis patens (Orchidaceae), Annals of the Tsukuba Botanical Gardens, 16, 69

Sugiura, 1997, Pollination of Goodyera foliosa var. maximowicziana (Orchidaceae) by the bumblebee Bombus diversus diversus, Plant Species Biology, 12, 9, 10.1111/j.1442-1984.1997.tb00151.x

Sun, 1996, Effects of population size, mating system, and evolution origin on genetic diversity in Spiranthes sinensis and S. hongkongensis, Conservation Biology, 10, 785, 10.1046/j.1523-1739.1996.10030785.x

Sun, 2001, Genetic structure of three orchid species with contrasting breeding system using RAPD and allozyme markers, American Journal of Botany, 88, 2180, 10.2307/3558379

Sydes, 1993, Comparative reproductive biology of two sun-orchids; the vulnerable Thelymitra circumsepta and the widespread T. ixioides (Orchidaceae), Australian Journal of Botany, 41, 577, 10.1071/BT9930577

Tanaka, 1984, Orchid biology: reviews and perspectives, 323

Thien, 1972, The floral biology of Arethusa bulbosa, Calopogon tuberosus and Pogonia ophioglossoides (Orchidaceae), Canadian Journal of Botany, 50, 2319, 10.1139/b72-300

Thien, 1970, The mode of pollination in Habenaria obtusata (Orchidaceae), American Journal of Botany, 57, 1031, 10.1002/j.1537-2197.1970.tb09905.x

Tollsten, 1989, Variation and post-pollination changes in floral odours released by Platanthera bifolia (Orchidaceae), Nordic Journal of Botany, 9, 359, 10.1111/j.1756-1051.1989.tb01011.x

Tollsten, 1993, Fragrance chemotypes of Platanthera (Orchidaceae) − the result of adaptation to pollinating moths?, Nordic Journal of Botany, 13, 607, 10.1111/j.1756-1051.1993.tb00105.x

Tremblay, 1992, Trends in pollination biology of the Orchidaceae. Evolution and systematics, Canadian Journal of Botany, 70, 642, 10.1139/b92-083

Tremblay, 1994, Frequency and consequences of multi-parental pollinations in a population of Cypripedium calceolus L. var. pubescens (Orchidaceae), Lindleyana, 9, 161

Tremblay RL 1996. Sex in small populations and evolutionary processes PhD Thesis

Tremblay, 1997a, Morphological variance among populations of three tropical orchids with restricted gene flow, Plant Species Biology, 12, 85, 10.1111/j.1442-1984.1997.tb00160.x

Tremblay, 1997b, Lepanthes caritensis, an endangered orchid: no sex, no future?, Selbyana, 18, 160

Tremblay, 1997c, Distribution and dispersion patterns of individuals in nine species of Lepanthes (Orchidaceae), Biotropica, 29, 38, 10.1111/j.1744-7429.1997.tb00004.x

Tremblay, 2001, Gene flow and effective population size in Lepanthes (Orchidaceae): a case for genetic drift, Biological Journal of the Linnean Society, 72, 47, 10.1111/j.1095-8312.2001.tb01300.x

Tremblay, 1998, Ecological correlates of rarity in the epiphytic orchid Lepanthes caritensis (Orchidaceae), Biological Conservation, 85, 297, 10.1016/S0006-3207(97)00163-8

Ushimaru, 2001, Evolution of flower allometry and its significance for pollination success in the deceptive orchid Pogonia japonica, International Journal of Plant Science, 162, 1307, 10.1086/322944

Vallius, 2000, Position-dependent reproductive success of flowers in Dactylorhiza maculata (Orchidaceae), Functional Ecology, 14, 573, 10.1046/j.1365-2435.2000.t01-1-00450.x

Vallius, 2001, Factors affecting fruit and seed production in Dactylorhiza maculata (Orchidaceae), Botanical Journal of the Linnean Society, 135, 89, 10.1111/j.1095-8339.2001.tb01083.x

Vallius, 2000., Effects of defoliation on male and female reproductive traits of a perennial orchid, Dactylorhiza maculata, Functional Ecology, 14, 668, 10.1046/j.1365-2435.2000.00467.x

Van Der Pilj, 1966., Orchid flowers: their pollination and evolution.

Vaughton, 1991, Variation between years in pollen and nutrient limitation of fruit set in Banksia spinulosa, Journal of Ecology, 79, 389, 10.2307/2260721

Vitt, 1997, Reproductive biology of Isotria medeoloides (Orchidaceae), Rhodora, 99, 56

Vogel, 1972, Pollination von Orchis papilionacea L. in den Schwarmbahnen von Eucera tuberculata, Jahresberichte des Naturwissenschaftlichen Vereins in Wuppertal, 25, 67

Vogel, 1974, Ölblumen und ölsammelnde Bienen, Tropische und Subtropische Pflanzenwelt, 7, 285

Vogel, 1981, Bestäubungs Konzepte der monokotylen und ihre Ausdruck im System, Berichte der Deutschen Botanischen Gesesllschaft, 94, 667

Vöth, 1982, Die ‘augeborgten’ Bestäuber von Orchis pallens L, Die Orchidee, 33, 196

Wade, 1991, Genetic variance for rate of population increase in natural populations of flour beetles, Trilobium spp, Evolution, 45, 1574, 10.1111/j.1558-5646.1991.tb02664.x

Waite, 1991, Population ecology of terrestrial orchids., 103

Wallace, 1858, On the tendency of varieties to depart indefinitely from the original type, Journal of the Proceedings of the Linnean Society, Zoology, vol

Wallace, 1974, The pollination of Liparis reflexa (R. Br.) Lindl, The Orchadian, 4, 106

Wallace, 2002, Examining the effects of fragmentation on genetic variation in Platanthera leucophaea (Orchidaceae): Inferences from allozyme and random amplified polymorphic DNA markers, Plant Species Biology, 17, 37, 10.1046/j.1442-1984.2002.00072.x

Wallace, 2000, Contrasting diversity between Northern and Southern populations of Cypripedium parviflorum (Orchidaceae): Implications for Pleistocene refugia and taxonomic boundaries, Systematic Botany, 25, 281, 10.2307/2666643

Waples, 1989, A generalized approach for estimating effective population size from temporal changes in allele frequency, Genetics, 121, 379, 10.1093/genetics/121.2.379

Waples, 1991, Genetic methods for estimating the effective size of cetacean populations, Report of the International Whaling Commission (special issue), 13, 279

Waser, 1991, Outcrossing distance and fecundity in Delphinium nelsonii: pollen load, pollen tube number, and seed set, Ecology, 72, 171, 10.2307/1938912

Weiner, 1984, The meaning and measurement of size hierarchies in plant populations, Oecologia (Berlin), 61, 1237, 10.1007/BF00379630

Whigham, 1990, The effect of experimental defoliation on the growth and reproduction of a woodland orchid, Tipularia discolor, Canadian Journal of Botany, 68, 1812, 10.1139/b90-234

Whigham, 1980, Studies on the pollination ecology of Tipularia discolor (Orchidaceae), American Journal of Botany, 67, 550, 10.1002/j.1537-2197.1980.tb07683.x

Whigham, 1988., Plant form and vegetation structure, 243

Whigham, 1991, Population ecology of terrestrial orchids., 89

Willems, 1997, Impact of pollination and resource limitation on seed production in a border population of Spiranthes spiralis (Orchidaceae), Acta Botanica Neerlandica, 46, 365, 10.1111/plb.1997.46.4.365

Williams, 1972, Selective attraction of male euglossine bees to orchid floral fragrances and its importance in long distance pollen flow, Evolution, 26, 84, 10.1111/j.1558-5646.1972.tb00176.x

Williams, 1983, Orchid floral fragrances and male euglossine bees: methods and advances in the last sesquidecade, Biological Bulletin of the Marine Biological Laboratory, Woods Hole, 164, 355, 10.2307/1541248

Williams, 1999, Molecular phylogeny and floral fragrances of male euglossine bee-pollinated orchids: A study of Stanhopea (Orchidaceae), Plant Species Biology, 14, 129, 10.1046/j.1442-1984.1999.00016.x

Williams, 1994, Observations on reproduction in Triphora trianthophora (Orchidaceae), Rhodora, 96, 30

Willson, 1979, Sexual selection in plants, American Naturalist, 113, 777, 10.1086/283437

Willson, 1983., Mate choice in plants: tactics, mechanisms and consequences.

Willson, 1977, The evolution of inflorescence size in Asclepias (Asclepiadaceae), Evolution, 31, 495, 10.1111/j.1558-5646.1977.tb01040.x

Willson, 1974, Adaptive design of the floral display in Asclepias syriaca L, American Midland Naturalist, 92, 47, 10.2307/2424201

Wirth, 1959, The orchids: a scientific survey., 155

Withner, 1976., First symposium on the scientific aspects of orchids., 34

Wong, 1999, Reproductive biology and conservation genetics of Goodyera procera (Orchidaceae), American Journal of Botany, 86, 1406, 10.2307/2656923

Wright, 1939., Statistical genetics in relation to evolution., 5

Wright, 1968., Evolution and the genetics of populations

Wright, 1969., Evolution and the genetics of populations

Wright, 1977., Evolution and the genetics of populations

Wright, 1978., Evolution and the genetics of populations

Wyatt, 1982, Inflorescence architecture: how flower number, arrangement, and phenology affect pollination and fruit-set, American Journal of Botany, 69, 585, 10.1002/j.1537-2197.1982.tb13295.x

Zar, 1996., Biostatistical analysis

Zettler, 1990, The status of Platanthera integrilabia, an endangered terrestrial orchid, Lindleyana, 5, 212

Zimmerman, 1991, Ecological correlates of labile sex expression in the orchid Catasetum viridiflavum, Ecology, 72, 597, 10.2307/2937200

Zimmerman, 1989, Patterns of fruit production in a neotropical orchid: pollinator vs. resource limitation, American Journal of Botany, 76, 67, 10.1002/j.1537-2197.1989.tb11286.x

Zimmerman, 1989, Asynchronous phenologies of a neotropical orchid and its euglossine bee pollinators, Ecology, 70, 1192, 10.2307/1941389

Zimmerman, 1992, Ecological functions of carbohydrates stored in corms of Tipularia discolor (Orchidaceae), Functional Ecology, 6, 575, 10.2307/2390055

Zimmerman, 1988., Reproduction in Polemonium: assessing the factors limiting seed set, American Naturalist, 131, 723, 10.1086/284815