Flora of New Zealand Series

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

S. inundatus (R.Br.) Spreng. var. major Cheesem. Man. N.Z. Fl. 1906, 775.

Type: Australian. Also recorded from Malaysia, S. America and Norfolk Id.

Culms 6–30–(50) cm. × (0.4)–0.7–1.2–(1.8) mm., tufted, ∞, erect, often rather rigid, terete, bright green. Lvs 1, or rarely 2–3 at the base of the culm, < 1 mm. wide; frequently reduced to a single, mucronate, red basal bract, mucro us. short. Infl. an apparently lateral, solitary head of (1)–3–6–(10) crowded spikelets, often proliferous with 1–3 slender branchlets each terminated by a smaller head of spikelets, subtending bract us. slightly > spikelets. Spikelets (2)–3–4–(5) × 1.5–2.5–(3) mm., ovate or oblong-ovate, often dark red-purple. Glumes 1.5–2 mm. long, oblong-obovate, obtuse or ± acute, with a large dark red to black patch on either side of the pale green keel, with ∞ distinct, light brown nerves, margins entire, white and membr., flattened at the tip beside the keel. Hypog. bristles 0. Stamens 1, very rarely 2. Style-branches 3, or rarely 2–3. Nut c. 1 × 0.5 mm., slightly > ½ length of glume, conspicuously trigonous or occ. biconvex, distinctly mucronate, pale strawcoloured, almost white, occ. grey-brown, surface distinctly reticulate.

DIST.: N. Throughout. S. Nelson, Westland, rather rare elsewhere. Ch.

Damp ground, sea level to 600 m. altitude.

Cheeseman (loc. cit.) described plants of S. inundatus as var. major to distinguish them from Isolepis reticularis Col. which he treated as S. inundatus var. gracillimus. AK 2123, Kaitaia, T. F. Cheeseman, Jan., 1896, is labelled S. inundatus var. major in Cheeseman's hand.

Distinguished from S. prolifer by the shorter, broader spikelets and 1–(2) stamens instead of 3. Plants of S. inundatus often have true lvs but S. prolifer is invariably leafless.

Small plants are occ. difficult to distinguish from S. reticularis but the glumes in S. inundatus are obtuse and flattened towards the tip while in S. reticularis they are acute and pinched in at the tip.