Brittonia

, Volume 53, Issue 2, pp 352–369

Significance of gametophyte form in long-distance colonization by tropical, epiphytic ferns

  • Cynthia L. Dassler
  • Donald R. Farrar
Articles

DOI: 10.1007/BF02812705

Cite this article as:
Dassler, C.L. & Farrar, D.R. Brittonia (2001) 53: 352. doi:10.1007/BF02812705

Abstract

Gametophyte morphology of tropical epiphytic ferns may confer an advantage for establishment on islands. Most tropical, epiphytic ferns belong to five families: Hymenophyllaceae, Grammitidaceae, Vittariaceae, Polypodiaceae, and Elaphoglossaceae. Gametophytes of these families are long-lived and clone-forming. In addition, most Hymenophyllaceae, Grammitidaceae, and Vittariaceae produce dispersible gemmae. Each of these characteristics increases opportunity for outbreeding, and when island floras are statistically compared with floras of adjacent mainlands, island floras are found to be rich in epiphytic species possessing gemmae (Hymenophyllaceae, Grammitidaceae, and Vittariaceae), and depauperate in epiphytic species lacking gemmae (Polypodiaceae and Elaphoglossaceae). We propose that gametophytic gemmae significantly aid long-distance colonization of outbreeding species because gemmae 1) allow gametophytes to exploit available niches through dispersal of gemmae, and through clonal expansion and persistence of the resulting gametophyte, and 2) facilitate sexual reproduction by providing the opportunity for sperm and antheridiogen transfer when gametophytes are distant, and by providing a new source of tissue for antheridia formation.

Key words

epiphytefernsgametophytegemmaelong-distance colonization

Copyright information

© The New York Botanical Garden Press 2001

Authors and Affiliations

  • Cynthia L. Dassler
    • 1
  • Donald R. Farrar
    • 1
  1. 1.Department of BotanyIowa State UniversityAmesU.S.A.