IX.—A Cytotaxonomic Survey of the Pteridophytes of Jamaica

Abstract

SynopsisResults are presented of a cytological survey of the Pteridophyte flora of Jamaica. Approximately 270 species or cytotypes were investigated, only a few of which have previously been investigated from other parts of the world. Several genera have been cytologically examined for the first time and their phylogeny has been discussed in the light of these findings. A number of species complexes and interspecific hybrids have been revealed. The overall statistics of the survey are compared with those compiled from an investigation of the Pteridophyte flora of Ceylon, by Manton and Sledge (1954). Finally, endemic species are discussed in the light of the cytological results and the time known to have been available for their establishment in Jamaica.

Cariologia de algumas espécies de Pteridófitas ocorrentes no nordeste do Brasil

“…10). Não foi encontrada nenhuma análise mitótica prévia dessa espécie, entretanto, diversos autores (Manton & Sledge 1954;Fabri 1963;Walker 1966;Smith & Mickel 1977;Moore 1974;Walker 1985;Goldblatt & Johnson 1990;1991) descreveram seu número meiótico, n=30, e o número básico do gênero, x=30.…”

“…Posteriormente, diversas floras pteridofíticas começaram a ser estudadas citotaxonomicamente, como a do Sri Lanka (Manton & Sledge 1954), Jamaica (Walker 1966) e Trinidad (Walker 1985). O avanço da investigação citológica da flora pteridofítica contribuiu para o entendimento dos mecanismos de evolução do grupo.…”

A Unified Approach to Taxonomic Delimitation in the Fern Genus <I>Pentagramma</I> (Pteridaceae)

“…Ferns are well known for their high levels of polyploidy (e.g. Walker 1966Walker , 1984Manton and Vida 1968;Löve et al 1977) and frequently limited suite of morphological characteristics. We believe that our approach, although here restricted in sample size and sequencing breadth, represents a workable solution for understanding the evolutionary history of this important group of plants.…”

Studies on the cytology of South Indian Aspidiaceae.

“…Manton (1950,1953,1959), Manton and Sledge (1954), Mehra (1961), Abraham et al (1962), Walker (1966) and Kuriachan (1973) have shown that polyploidy is of common occurrence among leptosporangiate ferns. Out of the 46 taxa investigated in the present study, 23 are polyploids.…”

“…Previous cytological studies on homosporous ferns have revealed the existence of several hybrids among them (Manton 1950, 1953, 1959, Manton and Sledge 1954, Mehra 1961, Walker 1966, Hirabayashi 1967and Kurita 1967. Abra ham et al (1962) have shown that 8 out of the one hundred ferns studied by them were hybrids.…”