A cytotaxonomic survey of the Pteridophyta of Australia

Abstract

All enquiries and manuscripts should be directed to:An international journal devoted t o t h e t a x o n o my, b i o g e o g r a p hy and evolution of all plant groups a u s t r a l i a n s y s t e m a t i c b o t a n yAbstract. A cytotaxonomic survey of the ferns and fern allies of Australia (including Lord Howe Island) is presented. Five-hundred-and-twenty-six chromosome counts of 268 Australian species, subspecies, varieties, variants and hybrids are recorded, only a small number having been previously investigated by other botanists on Australian material. Diploids represent c. 62% of the counts on species and c. 38% on polyploids, the latter ranging principally from triploids to a single decaploid and dodecaploid (but no heptaploids). More than one ploidy level has been reported in 19 taxa (almost 8% of taxa). Counts of 10x for Asplenium aethiopicum and 12x for A. flabellifolium are the highest definite ploidy levels for the Australian pteridophyte flora. Chromosome counts for 29 families and 89 genera are cited. Only diploids were reported for Osmundaceae and Cyatheaceae, but only polyploids for the Psilotaceae, Vittariaceae and Ophioglossaceae. An analysis is given of the levels of ploidy in 248 taxa, excluding the Lycopodiaceae and Hymenophyllaceae. The percentages of diploids and polyploids in Australian species are compared with those of nearby countries. Many species reported on here have never been cytologically investigated before, while others have not been studied previously on Australian material. The following genera have been examined cytologically for the first time: Coveniella Tindale, n = 41; Paraceterach (F.Muell.) Copel., n = 29; 'Oenotrichia Copel.', 2n = 82 (2x); Revwattsia (Watts) D.L.Jones, 2n = c. 328 (8x); and Pteridoblechnum Hennipman (2n = 54). The phylogeny of the genera is discussed in the light of these findings. Certain families such as the Adiantaceae, Cyatheaceae, Hymenophyllaceae, Lindsaeaceae and Marsileaceae were given special attention by collecting as much living material as possible. A number of species-complexes has been found and further chromosome counts added to intercontinental species complexes. The Döpp-Manton and Braithwaite forms of reproductive apomixis have been reported amongst some genera. Endemism, hybridity and apogamy amongst Australian pteridophytes are discussed, as well as homosporous and heterosporous species. The new combination Phymatosorus membranifolius (R.Br.) Tindale is made. S B 0 0 0 3 4 C y t o t a x o n o mi c s u r v e y o f t h e P t e r i d o p h y t a o f A u s t r a l i a

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).…”

A conspectus of the Native and Naturalized Species of Nephrolepis (Nephrolepidaceae) in the World

“…Basic chromosome number is 41 for all species investigated so far, and most species appear to contain diploids only, with additional tetraploids reported in two species (Löve et al, 1977;tindale & roy, 2002): in N. hirsutula in south india (probably this record refers to N. brownii) and in N. pectinata in Jamaica. Hybridization under natural circumstances occurs occasionally (Nauman, 1979b), but is probably far less common than sometimes supposed; the rampant hybridity suggested by some authors can probably for a large part be explained by an incomplete understanding of the natural species.…”

Lastreopsis kermadecensis, a new fern species from Raoul Island in the Kermadec Islands, New Zealand, with notes onL. pacifica

“…The spores of all three species are normally formed. No chromosome counts have been made for L. calantha but, with spore size often being a good predictor of ploidy (Perrie et al 2003), it is probably diploid like L. smithiana (Tindale & Roy 2002 Lastreopsis kermadecensis is morphologically most similar to L. smithiana, an Australian endemic with a markedly disjunct distribution, occurring around the eastern part of the New South Wales/Queensland border and again near Mackay (Jones 1998). Lastreopsis smithiana and L. kermadecensis both have rhizomes that are erect or short-creeping with fronds clustered at the apex (occasionally with the fronds distant in L. smithiana); indumentum of ctenitoid hairs of similar kind, size and distribution (Fig.…”

“…Perrie et al 2010b) in the genus, being otherwise known only in the New Zealand endemics, L. glabella and L. microsora subsp. pentangularis (Colenso) Tindale, which are also both tetraploids (Tindale & Roy 2002). An allo-tetraploid origin of L. kermadecensis would reinforce the taxonomic rank used here (Perrie et al 2003;Perrie et al 2010a); allopolyploidy can easily be overlooked using morphological consideration alone (Shepherd et al 2008).…”

“…About 36 species of Lastreopsis are currently recognised (Jones 1998;Tindale & Roy 2002;Mickel & Smith 2004), with rainforest being the usual habitat. Australia, including its territories, has the greatest diversity with 17 species (Green 1994;Jones 1998), but the genus also occurs in tropical America, tropical Africa, Madagascar, southern and eastern Asia, New Zealand, and the western and central Pacific (Tindale 1965).…”