Flora of New Zealand Series

Isolepis cartilaginea R.Br. Prodr.  1810,  222.

Scirpus cartilagineus (R.Br.) Spreng. Syst. Veg.  1,  1825,  208.

Type locality: S. African. Also recorded from Australia and S. America.

Annual, in dense, rigid tufts. Culms (0.5)–2–7 cm. × c. 0.5 mm., erect. Lvs 1–3, much < to almost = culms, rigid and coriac.; sheaths very pale brown, tinged red at the mouth or entirely red-brown. Infl. apparently lateral, of 1–4 spikelets; subtending bract > spikelets, up to 1.5 cm. long, rigid. Spikelets 2.5–4 × 1.5–2 mm., elliptical or ovoid, dark markings conspicuous. Glumes 1.5–2 mm. long, rigid, boat-shaped, incurved, broadly ovate, yellow with a large red-brown patch on each side towards the tip, marked with deeply incised curved lines, strongly keeled, keel green towards the ± excurrent tip, margins entire. Hypog. bristles 0. Stamens 3. Style-branches 3. Nut c. 1 mm. long, slightly > 0.5 mm. wide, elliptic-obovoid, trigonous with subacute angles, minutely apiculate, occ. with a black tip, broadly stipitate, bright yellow to yellow-brown, very minutely punctulate and appearing smooth.

DIST.: N. Scattered localities, more common in Wellington Province. S. Nelson, Marlborough, Canterbury; local.

Both in dry places in sandy or stony ground and in poor depleted pasture, or in damper pakihi grassland.

Isolepis cartilaginea R.Br. Type locality: Australian.

A portion of a plant from Collingwood was grown for a year in Mr Pott's garden at Opotiki. When collected the plant was 4 cm. high (CHR 68762, L. B. Moore, 5/1/1947) but in cultivation the culms were up to 20 cm. long and spikelets up to 5 mm. long (CHR 61805 A & B). The red marks on the glumes were not as distinct in cultivation as in the wild.

Cook (T.R.S.N.Z. 81, 1953, 161) and Edgar (N.Z. J. Bot. 4, 1966, 198) used the name S. cartilagineus for the N.Z. plants and stated that S. antarcticus was not found in N.Z. They followed Levyns (J. S. Afr. Bot. 10, 1944, 28) who noted that two entities were included within the South African S. antarcticus L., the larger and less common plant being the one to which the name S. antarcticus was originally applied, the smaller, more widespread plant being S. cartilagineus. In view of further evidence on the variation in size of plant, number of spikelets and size of glumes in specimens throughout the range of the sp. it seems better to treat S. cartilagineus as conspecific (see Blake, Contrib. Qd Herb. no. 8, 1969, 17).

The glumes are distinct from those of all other N.Z. spp., being boat-shaped with deeply incised marks on each side.