Observations on the cytology and taxonomy of the pteridophyte flora of Ceylon

Abstract

Cytological observations have been made on 155 entities (excluding sterile hybrids) referable provisionally to ca. 140 existing taxa in the fern flora of Ceylon. These have been supplemented by observations on 69 entities (involving 46 additional species) from wild material of ferns from other countries, chiefly Malaya, and on 15 additional species of unknown wild origin growing at Kew. The cytological findings are assembled in relation to the taxonomic system of Copeland (1947) which is discussed in a preliminary way together with the relevant portions of the alternative system of Holttum (1947).

A review of the genus <i>Stenochlaena</i> (Blechnaceae, subfamily Stenochlaenoideae)

“…1) bilateral, ellipsoid, somewhat hyaline, colourless to pale yellow, papillose with distant tubercles tending to be in parallel rows and with an exceptionally thin, closely adhering perispore. Mehra & Bir (1958) reported the distinct chromosome number of n = 73 for Stenochlaena and concluded, on the basis of investigation of a number of morphological characters of Stenochlaena palustris, that a phylogenetic relationship exists between Stenochlaena and the members of the family Blechnaceae.This report of n = 73 (or 74) is further supported by Tindale & Roy (2002) with 2n = c.146 for material collected from Iron Range in North Queensland, Australia, and by the earlier report of x = 37; 4n = 148 by Manton & Sledge (1954).…”

“…Chromosome number: x = 74 (base number may be 37; Kramer & Green (1990), a number occasionally also reported for Blechnum). Mehra & Bir (1958) illustrate a spore mother cell at meiosis with 73 bivalents, while Manton (1954) and Manton & Sledge (1954) have suggested that n = 70-80 and most probably n = 74 and 2n = c. 148. (Fig.…”

Ornamental pteridophytes: an underexploited opportunity for the Sri Lankan floriculture industry

“…Among Asian countries, Sri Lanka is second only to Taiwan in terms of the number of pteridophyte species per 10,000 square kilometres (Ranil et al, 2008a (Manton & Sledge, 1954;Sledge, 1982). Recently, various Sri Lankan researchers have published work on peteridophytes, culminating in the publication of A Revised Handbook to the Flora of Ceylon, volume XV: Fern and Fern-Allies (Shaffer-Fehre, 2006).…”

A plastid phylogeny and character evolution of the Old World fern genus Pyrrosia (Polypodiaceae) with the description of a new genus: Hovenkampia (Polypodiaceae)

“…A large number of potential hybridization and polyploidization have been proposed based chromosome numbers (e.g., Manton and Sledge, 1954;Abraham et al, 1962;Patnaik and Panigrahi, 1963;Hovenkamp, 1986), morphology (e.g., Serizawa, 1970;Beppu and Serizawa, 1982), and most recently molecular data (Choi and Park, 2016) in Pyrrosia. Notably, previous studies suggest that hybridization and polyploidization are mainly found in the Neoniphopsis clade.…”