Flora of New Zealand Series

Dioec. Infl. a terminal panicle on a lfless simple peduncle; spathes large and foliaceous, each us. subtending a simple raceme; racemes few, often ± uniform in size, and well-spaced; bracteoles membr., us. small; fls small, us. ∞, crowded, ♂ much larger than ♀. Per. membr., tube deeply campanulate to urceolate, lobes narrow, strongly reflexed. Stamens in ♂ conspicuous; anther linear-hastate, dorsifixed, immobile; in ♀ minute with flat, empty anthers. Ovary superior, 3-locular; placentae on the septa; ovules few to many, smaller in ♂ but us. identifiable, ± embedded in mucilaginous funicular hairs; style short and thick; stigmatic surfaces 3, ± confluent, long-papillose; nectaries 3, slit-like. Fr. a berry. Seeds black, the surface us. dull and ridged and ± coated with funicular hairs. Tufted herbs, primarily epiphytic or rupestral, characterised by peculiar indumentum of scales. Stem short, us. hidden. Lvs 3-ranked but sts appearing distichous, linear-ensiform, expanding below into broad, closed, often blackish sheathing base; midrib stout, sunken above, prominent below; nerves ∞, us. one costa on each side of midrib strongly incrassate, especially adaxially; transverse veinlets distinct, especially in sheath. Four spp., one in Samoa, one in Fiji and 2 endemic in N.Z.

Skottsberg (K. svenska Vet. Akad. Handl. 14, 1934. 72), in segregating Collospermum from Astelia, indicated no type sp. and C. hastatum (Col.) Skottsb. is here designated lectotype. N.Z. spp. are discussed by Wheeler (N.Z. J. Bot. 4, 1966, 95–113. cytotaxonomy) and by Moore (N.Z. J. Bot. 4, 1966, 201–240.)

Maori names listed for Collospermum are Kahakaha, Kokaha, Takahakaha.

Though of similar habit to the larger spp. of Astelia  Collospermum spp. can be recognised by several features. The lf-sheath is us, but not always blackish; it is not keeled or constricted where it merges into the lamina and so forms an open, funnel-shaped receptacle where water and debris collect. Scales on the abaxial lf-surface are ± peltate and dark-centred. The deep per.-tube distinguishes the fls from those of A. solandri, A. trinervia and A. banksii, and the whole per. remains membr. instead of becoming fleshy as in Astelia spp. of the subgenus Tricella. Seeds of C. hastatum are quite distinctive, but those of C. microspermum resemble Astelia seeds rather closely.

Fig. 9. COLLOSPERMUM. C. microspermum : male flower; female flower; fruit; seed; ovule with short funicle-hairs; T.S. ovary showing large median mucilage duct in wall of each locule. C. hastatum : ovule and seed with long mucilaginous funicle-hairs; T. S. ovary. © All rights reserved. [Image: 4X37]