Colobanthus affinis (Hook.) Hook.f.
Spergula affinis Hook. Ic. Pl. 3, 1840, t. 266.
Type locality: Tasmania. Type: K, "Hampshire Hills, Van Diemen's Land, R. Gunn, n. 967, Feb. 1837."
Clumps several cm. across formed of one or more plants. Branches many, mostly short, occ. 3, rarely 5 cm. long, clothed with old lf-bases. Lvs soft, ± grassy; sheath short, broad; blade 5-15-35 mm. long, linear, ending in short but definite apiculate tip. Peduncles about = lvs or longer. Fls very broad; sepals 5, ± 3 mm. long, much broader than lvs, ovate, obtuse or at most subacute, often purple-bordered; capsule valves up to ⅓ longer than sepals when fully open; seeds with very low rounded papillae only.
DIST.: N. Mt. Egmont, Maungapohatu, Ruahine Range, Tararua Range. S. Nelson, Kelly's Hill, Upper Arahura Valley, Huxley Valley, Clinton Valley, MacKinnon Pass, Caswell Sound area. Herbfield or fellfield, 1050-1500 m. altitude.
FL. 12-1. FT. 12-4.
The type specimens at Kew have peduncles reaching 30 mm. long in the fruiting state, a length attained in N.Z. plants in sheltered habitats. Otherwise specimens compared agree with the type. Tasmanian plants from Port Davy (F. H. Long, Feb. 1929) match N.Z. plants closely.
In the broad subacute sepals, not exceeding capsule length, C. affinis differs from all other spp. of similar habit in N.Z. and resembles C. crassifolius (D'Urv.) Hook. f. from Falkland Is. D'Urville's description of Sagina crassifolia (Mem. Soc. linn. Paris 4, 1826, 617) gives the lvs as linear, mucronate at the tip, sepals 4, lanceolate, subequal to the capsule. Plants determined as C. crassifolius and lent for study by the Botanical Department of the State Muscum of Natural History, Stockholm, include many plants with 5-merous fls, amongst them a sheet from "Killy's Range [Kelly's Hill], in alpibus ins. austr. Novae Zelandiae. Febr. 1874. S. Berggren." Of the specimens from the type locality, Falkland Is, even those most like the N.Z. specimens here attributed to C. affinis show several points of difference. Characteristic of the N.Z. plants are the constantly present small colourless apicula to the If which is itself narrower and less fleshy, the almost invariably 5-merous fls (4- and 5-merous fls occur frequently in the same clump from Falkland Is, though occ. a uniformly 4- or 5-merous plant is seen), and the sepals generally very much shorter than the mature capsule. Lf tip and sepal features have been found to be more reliable than If shape and size which in many spp. of Colobanthus can be altered greatly in one plant in cultivation.
Plants of this kind were apparently not known to T. Kirk who states under C. billardieri (Stud. Fl. 1899, 60) "Colobanthus affinis Hook., figured in Ic. Pl. t. 266, differs from any form of C. Billardieri found in New Zealand in the broadly ovate sepals, which are only half the length of the capsule, and in the broad disc."
