n = 9. Figs. 19-21, 61m, n.
Hypnodendron marginatum is a New Zealand endemic occurring on both the North and South Islands. It is a tall (13 cm) dendroid species bearing many sporophytes, to 38 per frond, growing only under very wet conditions, sometimes almost submerged. Adaptation to the aquatic habitat has resulted in rather diflferent leaves compared with the other taxa in secrion % . nodendron (Touw, 1971). No previous chromosome records are available for H. marginatum. The chromosome number n = 9 (Figs. 19 & 21) was the same as that for other members of this section. Results were obtained from three populations (Table I, Appendix I). The nine bivalents consisted of four larger, three intennediate and two smaller ones (Figs. 19-21). A rodshaped bivalent was noted in some cells (Fig, 6In) and one bivalent was observed to disjoin early in some ceUs (Fig. 61m). The alignment of the bivalents (Fig. 20) confirms this species as having a complement which is morphologically comparable to the two other species examined in this section, H. spininervium and H. vitiense, but with its own characteristics.