Studies in Schizaea fistulosa Labill (1966)
AuthorsLash, Ianshow all
The Schizaeaceae is one of the most primitive families in the Filicales and one of the oldest surviving fern families (Arnold, 1947). It is divided into four genera: Schizaea, Lygodium, Anemia and Ivlohria. These four genera include approximately 175 species, of which Schizaea was first described by Smith in 1793. Since then there have been attempts to divide it into more genera, but it is now divided into sections and sub-sections which as listed below are from Selling (1944). Section I. Euschizaea, Hook. Sub. section 1. Pectinatae, Prantl. Sub. section 2. Bifidae, Prantl. Section II. Actinostachys, Wall. (Synonym. Section I. Digitatae, Prantl). Section III. Lophidium, Rich, Sub. section 1. Dichotomae, Prantl. Sub. section 2. Elegantes, Prantl. All the species, except one, which are mentioned in this thesis are in Section I, Sub. section 1, the exception being Schizaea. bifida Sw. which is in the same section but in Sub. section 2. The systematic classification of Schizaea fistulosa sens. lat. has been far from clear since the original description by de Labillardiere in 1806. The object of this thesis is to endeavour to clarify this situation and to either confirm or disprove the valldity of the grouping into S. Fistulosa Labill. (Plate No.1) and S. fistulosa var. australis Hook. f. (Plate No.2). To carry out the study on S. fistulosa sense lat. four lines of observation have been followed:- 1. General external morphology. 2. Spore morphology. 3. Development of gametophytes. 4. Chromosome numbers. The first two of these have been carried out on all available material from the total geographic range of the species, while for the latter two live material collected in New Zealand has been used. To all material, live and herbarium, I have given a number of my own for convenience when quoting in the text. A list with corresponding Herbaria numbers appears in the appendix at the end.