Dioecy hotspots in Southeast Florida (U.S.A.), especially Saw Palmetto (Serenoa repens, Arecaceae) thickets


  • George K. Rogers Palm Beach State College




Breeding systems, dioecy rates, hummocks, seedling recruitment, shade, Florida wetland ecology


A survey of woody marshland hummocks, of Saw Palmetto (Serenoa repens, Arecaceae) thickets, and of additional Southeast Florida habitats revealed multiple sites with dioecy rates of 50–100%, especially in the Saw Palmetto thickets. These rates exceeded any encountered for woody species in a literature review globally or for Florida. A particularly notable feature of the thicket sites is extreme thick low-elevation palm frond canopy coverage, consistent with the historical perspective that a benefit of dioecy is sexual selection for seed quality where harsh ecological filters limit establishment.


ADAM, P. & G. WILLIAMS. 2001. Dioecy, self-compatibility and vegetative reproduction in Australian subtropical rainforest trees and shrubs. Cunninghamia 7:89–100.

ARMENTANO, T., D. JONES, M. ROSS, & B. GAMBLE. 2002. Vegetation pattern and process in tree islands of the southern Everglades and adjacent areas. In: F. Sklar & A. van der Velk, eds. Tree islands of the Everglades. iv + 541 p. Kluwer Academic Publishers, Dordrecht, Boston and London, U.K. Pp. 225–281.

BALESTRI, F. 2015. Horticultural potential of Nyssa biflora Walt. (swamp tupelo). Masters Thesis. Iowa State University. 81 p.

BARRETT, H. 1957. Vitis cinerea as a source of desirable characters in grape breeding. Proc. Amer. Soc. Hort. Sci. 70:165–168.

BARRETT S. & J. HOUGH. 2013, Sexual dimorphism in flowering plants. J. Exp. Bot. 64:67–82.

BAWA, K. 1980. Evolution of dioecy in flowering plants. Annual Rev. Ecol. Syst. 11:15–39.

BAWA, K. 1994. Pollinators of tropical dioecious angiosperms: a reassessment? No, not yet. Amer. J. Bot. 81:456–460.

BAWA, K. & P. OPLER. 1975. Dioecism in tropical forest trees. Evolution 29:167–179.

BRIZICKY, G. 1962. The genera of Anacardiaceae in the southeastern United States. J. Arnold Arbor. 43: 359–375.

BRUIJNING, M., M. VISSER, H. MULLER-LANDAU, S. WRIGHT, L. COMITA, S. HUBBELL, HANS DE KROON, & E. JONGEJANS. 2017. Surviving in a cosexual world: A cost-benefit analysis of dioecy in tropical trees. Amer. Naturalist 189:297–314.

BUCKLEY, N. & G. AVILA-SAKAR. 2013. Reproduction, growth, and defense trade-offs vary with gender and reproductive allocation in Ilex glabra (Aquifoliaceae). Amer. J. Bot. 100:357–364.

BULLOCK, S. 1985. Breeding systems in the flora of a tropical deciduous forest in Mexico. Biotropica 17:287–301.

CARLQUIST, S. 1965. Island life: A natural history of the islands of the World. Natural History Press, Garden City, New Jersey, U.S.A.

CARLQUIST, S. 1974. Island biology. xii + 660 pp. Columbia University Press, New York, U.S.A.

CARR, D. 1991. Sexual dimorphism and fruit production in a dioecious understory tree, Ilex opaca Ait. Oecologia 85:381–388.

CHARLESWORTH, D. 1999. Theories of the evolution of dioecy. In: M. Geber, T. Dawson, and L. Delph, eds. Gender and sexual dimorphism in flowering plants. Springer, Berlin, & Heidelberg. Pp. 33–60. https://doi.org/10.1007/978-3-662-03908-3_2

CHEN, X.-S. & Q.-J. LI. 2008. Sexual systems and ecological correlates in an azonal tropical forest, SW China. Biotropica 40:160–167.

COMEAU, P. 2000. Measuring light in the forest. British Columbia Minist. Forests Extens. Note 42:1–7.

CORRELL, D. & H. CORRELL. 1982 [reprinted 1996]. Flora of the Bahama Archipelago. Gantner, Vaduz, Germany.

Croat, T. 1979. The sexuality of the Barro Colorado Island flora (Panama)). Phytologia 42:319–348.

DARWIN, C. 1877. The different forms of flowers on plants of the same species. John Murray, London, UK.

FERRUFINO-ACOSTA, L., 2010. Taxonomic revision of the genus Smilax (Smilacaceae) in Central America and the Caribbean Islands. Willdenowia 40:227–280.

FLORES, S. & D. SCHEMSKE. 1984. Dioecy and monoecy in the flora of Puerto Rico and the Virgin Islands: ecological correlates. Biotropica 16:132–139.

FOX J. 1985. Incidence of dioecy in relation to growth form, pollination and dispersal. Oecologia. 67:244–249.

FREEMAN, D., J. DOUST, A. EL-KEBLAWY, K. MIGLIA, & E. MCARTHUR. 1997. Sexual specialization and inbreeding avoidance in the evolution of dioecy. Bot. Rev. (Lancaster) 63:65–92.

GANN G., C. ABBOTT C., K. HINES, & COLLABORATORS. 2005–2023. Natives for your neighborhood. The Institute for Regional Conservation. Delray Beach, Florida. Website https://www.regionalconservation.org/beta/nfyn/default.asp [accessed 1/22/2024].

GIBSON, D. & E. MENGES. 1994. Population structure and spatial pattern in the dioecious shrub Ceratiola ericoides. J. Veg. Sci. 5:337–346.

GILLESPIE, T. 2008. Sexual systems and fruit types in native dry forest trees in South Florida. Florida. Sci. 71:370–382.

GILLIS, W. 1971. The systematics and ecology of poison-ivy and the poison-oaks (Toxicodendron, Anacardiaceae). Rhodora 73:72–159 (with subsequent installments).

GILLIS, W. & G. PROCTOR. 1974. Caesalpinia subgenus Guilandina in the Bahamas. J. Arnold Arbor. 55:425–430.

GIVNISH, T. 1982. Outcrossing versus ecological constraints in the evolution of dioecy. Amer. Naturalist 119:849–865.

GODFREY, R. & J. WOOTEN. 1981. Aquatic and wetland plants of Southeastern United States. Dicotyledons. Univ. Georgia Press, Athens, Georgia, U.S.A.

HELD, B. 2017. Ecological correlates with dioecy in the flora of a tropical premontane wet forest in Costa Rica. Undergraduate Distinction Papers. 53.

HOGG, B., K. STOKES, M. RAYAMAJHI, J. GEIGER, & P. PRATT. 2020. Foliar lifespan, phenology and seasonal dynamics of the invasive shrub Schinus terebinthifolia. Weed Res. 60:212–220.

KEVAN, P., D. BLADES, U. POZLUSZNY, & J. AMBROSE. 1988. Pollen dimorphism and dioecy in Vitis aestivalis. Vitis 27:143–146.

LIN, H.-Y., Y.-H. TSENG, C.-F., HSIEH, & J.-M. HU. 2019. Geographical distribution of dioecy and its ecological correlates based on fine-scaled species distribution data from a subtropical island. Ecol. Res. (Tokyo) 35:170–181.

LIU, M., H. KORPELAINEN, & C. LI. 2021. Sexual differences and sex ratios of dioecious plants under stressful environments. J. Pl. Ecol. 14:920–933.

LONG, R. & O. LAKELA. 1971. A flora of Tropical Florida. Univ. Miami Press, Coral Gables, Florida, U.S.A.

MADRIZ, R. & N. RAMÍREZ. 1996, 1997. Biología reproductiva de Coccoloba uvifera (Polygonaceae) una especie poligamo-dioica. Rev. Biol. Trop. 44:105–115.

MAGUIRE, L., D. BARRIOS, E. DÍAZ, B. ZUMWALDE, W. TESTO, & V. NEGRÓN-ORTÍZ. 2021. Pleistocene aridification underlies the evolutionary history of the Caribbean endemic, insular, giant Consolea (Opuntioideae). Amer. J. Bot. 108:1–16.

MATALLANA, G., T. WENDT, D ARAUJO, & F. SCARANO. 2005. High abundance of dioecious plants in a tropical coastal vegetation. Amer. J. Bot. 92:1513–1519.

NESOM, G. 2010. Taxonomy of the water ashes: Fraxinus caroliniana, F. cubensis, and F. pauciflora (Oleaceae). Phytoneuron 2010-39:1–13.

OLIVEIRA, P. 1996. Dioecy in the cerrado vegetation of Central Brazil. Flora 191:235–243.

PORTER, D. 1976. Zanthoxylum (Rutaceae) in North America North of Mexico. Brittonia 28:443–447.

PRIMACK R. & C. MCCALL. 1986. Gender variation in a Red Maple population (Acer rubrum; Aceraceae): a seven-year study of a "polygamodioecious" species. Amer. J. Bot. 73:1239–1248.

QUEENBOROUGH, S., S. MAZER, S. VAMOSI, N. GARWOOD, R. VALENCIA, & R. FRECKLETON. 2009. Seed mass, abundance and breeding system among tropical forest species: do dioecious species exhibit compensatory reproduction or abundances? J. Ecol. 97:555–566.

R CORE TEAM. 2024. R: A language and environment for statistical computing. R Foundation for Statistical Computing, Vienna, Austria. https://www.R-project.org/.

RÉJOU-MÉCHAIN, M. & P. CHEPTOU. 2015. High incidence of dioecy in young successional tropical forests. J. Ecol. 103:725–732.

RENNER, S. 2014. The relative and absolute frequencies of angiosperm sexual systems: dioecy, monoecy, gynodioecy, and an updated online database. Amer. J. Bot. 101:1588–1596.

RENNER, S. & J. FEIL. 1993. Pollinators of tropical dioecious angiosperms. Amer. J. Bot. 80:1100–1107.

RENNER, S. & R. RICKLEFS. 1995. Dioecy and its correlates in the flowering plants. Amer. J. Bot. 82:596–606.

RENNER, S., L. BEENKEN, G. GRIMM, A. KOCYAN, & R. RICKLEFS. 2007. The evolution of dioecy, heterodichogamy, and labile sex expression in Acer. Evolution 61:2701–2719.

ROGERS, G. 2024. “Data for dioecy hotspots in southeast Florida, especially Saw Palmetto (Serenoa repens) thickets .” Mendeley Data, V1, doi: 10.17632/jt9frcrgfm.1

ROHWER, J. 1986. Some aspects of dioecy in Ocotea (Lauraceae). Pl. Syst. Evol. 152:47–48.

SACANDE, M. & H. VAUTIER. 2006. Ximenia americana L. Univ. Copenhagen Seed Leafl. 112.

SAKAI, A., W. WAGNER, D. FERGUSON & D. HERBST. 1995. Origins of dioecy in the Hawaiian flora. Ecology 76:2517–2529.

SOBREVILA, C. & M. ARROYO. 1982. Breeding systems in a montane tropical cloud forest in Venezuela. Pl. Syst. Evol. 140:19–37.

SPELLENBERG, R. 2003. In: Flora of North America Editorial Committee, eds. 1993+. Flora of North America North of Mexico [Online]. 22+ vols. New York, U.S.A and Oxford, UK. Vol. 4. http://floranorthamerica.org/Nyctaginaceae [accessed 6/7 2023].

STRITTMATTER, L., R. HICKEY, & V. NEGRÓN-ORTIZ. 2008. Heterochrony and its role in sex determination of cryptically dioecious Consolea (Cac-taceae) staminate flowers. Bot. J. Linn. Soc. 156:305–326.

TOMLINSON, P. 1974. Breeding mechanisms in trees native to tropical Florida—a morphological assessment. J. Arnold Arbor. 55:269–290.

TONNABEL, J., P. DAVID, & J. PANNELL. 2017. Sex-specific strategies of resource allocation in response to competition for light in a dioecious plant. Oecologia 185:675–686.

VAMOSI, J., S. OTTO, & S. BARRETT. 2003. Phylogenetic analysis of the ecological correlates of dioecy in angiosperms. J. Evol. Biol. 16:1006–1018.

VAMOSI, S. 2006. A reconsideration of the reproductive biology of the Atlantic forest in the Volta Velha reserve. Biodivers. & Conservation 15:1417–1424.

VAMOSI, S. & S. QUEENBOROUGH. 2010. Breeding systems and phylogenetic diversity of seed plants along a large-scale elevational gradient. J. Biogeogr. 37:465–476.

VAMOSI, S., S. MAZER, & F. CORNEJO. 2008. Breeding systems and seed size in a Neotropical flora: testing evolutionary hypotheses. Ecology 89:2461–2472.

VANOZZI, A., F. PALUMBO, M. LUCCHIN, & G. BARCACCIA. 2022. Dioecy in flowering plants: From the first observations of Prospero Alpini in the XVI Century to the most recent advances in the Genomics Era. Agriculture 12:https://doi.org/10.3390/agriculture12030364.

WAN, Y., H. SCHWANINGER, A. BALDO, J. LABATE, G.-Y. ZHONG, & C. SIMON. 2013. A phylogenetic analysis of the grape genus (Vitis L.) reveals broad reticulation and concurrent diversification during Neogene and Quaternary climate change. Evol. Biol. 13:141. https://doi.org/10.1186/1471-2148-13-141.

WUNDERLIN, R., B. HANSEN, A. FRANCK, & F. ESSIG. 2024. Atlas of Florida plants (http://florida.plantatlas.usf.edu/). [S.M. Landry and K.N. Campbell (application development), USF Water Institute.] Inst. Syst. Bot., Univ. South Florida, Tampa, U.S.A.

WUNDERLIN, R. & J. POPPLETON. 1977. The Florida species of Ilex (Aquifoliaceae). Florida Sci. 40:7–21.

ZONA, S. 1997. The genera of Palmae (Arecaceae) in the southeastern United States. Harvard Pap. Bot. 2:71–107.




How to Cite

Rogers, G. K. (2024). Dioecy hotspots in Southeast Florida (U.S.A.), especially Saw Palmetto (Serenoa repens, Arecaceae) thickets. Journal of the Botanical Research Institute of Texas, 18(1), 149–162. https://doi.org/10.17348/jbrit.v18.i1.1345