Characeae of New Zealand

Abstract

In this floristic study of the Characeae of New Zealand, 15 species are treated in accordance with Wood's revised classification; a key, brief descriptions, figures, distribution maps, and lists of specimens cited are given. Four genera are represented: Chara, Lamprothamnium, Nitella, and Tolypella. Two species are added to the flora: N. cristata and N. flexilis (with some doubt). The results tn general support the senior author's earlier revision, but newly recovered type material (MEL, BM) necessitates certain nomenclatural changes. There are two new varieties — C. braunii var. divergens R.D.W. var. nov. and N. hookeri var. masonae R.D.W. var. nov., and three new combmations — N. pseudoflabellata var. conformis (Nordst.) R.D.W. stat. et comb. nov., N. hookeri var. tricellularis (Nordst.) R.D.W. comb. nov., and N. cristata var. microcephala (Nordst.) R.D.W. comb. nov. The greatest remaining difficulties concern Nitella pseudoflabellata and the species pair complex of N. hookeri and N. cristata. As the Kerguelen type of N. hookeri is still not available, judgments arc based on the New Zealand lectotype, Colenso (not Taylor) 417 (BM). The New Zealand population is interpreted as a variable population of intergrading forms among which are two common extremes, a lax form (var. hookeri) and a capitate form (var. tricellularis), and also a newly recognised form with spicate heads (var. masonae). Previously published varieties are assigned to other species or to vars hookeri or tricellularis. N. hookeri appears to be the monoecious morphological equivalent or the dioecious N. cristata, a common Australian species sparse in New Zealand. The commonest species in decreasing order of frequency are Nitella hookeri. N. pseudoflabellata, N. hyalina, Chara corallina, and C. fibrosa. Species rare in New Zealand but common throughout most of the world are C. braunii, Tolypella nidifica, and C. vulgaris. No species are endemic. although one, N. hookeri, is abundant throughout but known elsewhere only as rare in Australia and Kerguelen Island. All New Zealand species are held in common with Australia and comparisons of the mode of occurrence of the species common to both countries suggest that all New Zealand charophytes may have been derived from Australia.