Perennial herb up to 10 cm tall; stems and rootstock slender. Radical leaves 7– 20 mm long, simple, densely covered with stellate hairs on petiole, lamina, and margin when young, becoming ± glabrous with age; early radical leaves often simple with few serrations, later leave s pinnatifid or pinnatisect, lobes in 2–4 opposite or subopposite pairs; lamina 4–9 × 1 .5–5 mm; petioles 3–14 × 0 .2–0.5 mm, channelled. Cauline leaves 1– 4, lower leaves similar to radical leaves, uppe r cauline leaves c. 3 × c. 0 .5 mm, linear, often with minute serrations. Inflorescences 4–10 cm long, with 3–10 flowers, peduncle at base c. 0.5 mm diam., racemose, glabrous or with sparse stellate hairs. Pedicels 8–12 × 0 .4–0.5 mm, glabrous. Peduncle, pedicels, and siliques with slight glaucous bloom. Sepals 1 .8–2.4 × 1 .0–1 .1 mm, ascending, oblong to elliptic, with sparse stellate hairs, green with pale margins, subacute. Petals 3 .0–5.0 × 0 .3–1 .0 mm, white, weakly obovate to obovate-spathulate, subacute, claw ± distinct; limb spreading. Stamens 4–6, of unequal lengths; filaments 1 .5–2.5 × c. 0.2 mm, linear; anthers 0 .4–0.7 mm long, yellow. Ovary at anthesis 2 .0–4 .0 × 0 .3–0.5 mm, terete, light brown or green-brown, glabrous; style 0.1–0.2 mm long, green; stigma c. 0.3 mm diam.; ovules 40–62. Siliques 15–25 × 0.7–1.0 mm, terete, often curved, glabrous; valves green in lower part, brown-green or light brown in the upper part. Seeds 0.6–0.9 mm long, short-oblong, pale brown, numerous and in one row in each locule. FL Oct–Nov; FT Oct Dec. Chromosome number 2n = 20 (M. I. Dawson pers. comm.; CHR 510585). Endemic .

Differt ab I. novae-zelandiae habitu exil i parvoque, folius, inflorescentiis, floribusqu e minoribus, etiam ovario tereti.

Small, greyish green or dull green, sometimes purple-tinged, short-lived perennial, forming slender tufts to c. 22 cm tall, branching extravaginally and occasionally intravaginally above; leaf-blades shorter than culms, wiry, persistent. Leaf-sheath pale brown to purplish, membranous, distinctly nerved, almost smooth abaxially with a few minute prickle-teeth just below ligule especially near the margins. Ligule 1-1.5 mm, ± lacerate with at least one deep cleft, abaxially minutely scabrous, tip dentate, ciliate. Leaf blade to 6 cm × 1 mm, folded, abaxially with sparse minute prickle-teeth on midnerve, elsewhere smooth, adaxially with minute stiff hairs, margins ± inrolled, with very minute prickle-teeth. Culms to 15 cm tall, very slender, purplish, smooth, with 1-2 cauline leaves spreading at right angles. Panicle 2-6 cm long, open, sparingly branched; rachis smooth, branches capillary, sometimes flexuous, smooth, with a few minute prickle-teeth above, and with 1 - 2 spikelets at tips. Spikelets 2 .2-3 mm, 2-3-flowered, silvery purplish green. Glumes subequal, 2-2.5 mm, with wide, hyaline margins, midnerve with sparse prickle-teeth near tip; lower narrower, elliptic-lanceolate, acute to acuminate, 1-3-nerved, upper ovate, obtuse, 3-nerved, sometimes with minute prickle-teeth on margins and on lateral nerves above. Lemma 2-2 .4 mm, 5-nerved, ovate, obtuse, covered for ¾ length with appressed, silky hairs c. 0.1 mm, and with sparse minute prickle-teeth near membranous tip. Palea c. 2 mm, with minute appressed hairs on keels and interkeels in lower ¾, with minute prickle-teeth on keels above. Callus with minute fine hairs. Rachilla to 0.5 mm with scattered long hairs or almost glabrous. Lodicules c. 0.4 mm. Anthers 0.7-1.1 mm, sometimes reddish. Gynoecium: ovary c. 0.5 mm; stigma-styles 1 - 1.4 mm. Caryopsis c. 1.5 × 0.7 mm. FL Nov-Jan, FT Dec-Mar. Chromosome number not determined. Chasmogamous. Endemic .

Gramen breviter perenne, parvum, griseo - viride, paniculis gracilibus folia involuta superantibus, lemmatibusque praeter in quarta parte superiore pilosis; Poam lindsayi multo simulans differt autem innovationibus praecipue extravaginalibus, ligul a longiore, ± lacerata non truncata, abaxialiter scabra, glumis, lemmatibus antherisque longioribus.