Isachne R. Br.

Wetlands

Conservation Actions

Perennial. Culms slender to moderately robust, erect or decumbent and rooting at lower nodes, up to 80 cm tall, nodes glabrous, eglandular or with glandular ring. Leaf sheaths shorter than internodes, glabrous except for ciliate outer margin; leaf blades narrowly lanceolate, 3–10 × 0.4–0.8 cm, glabrous, scabrid, base rounded, apex acute; ligule 1–2 mm. Panicle open, ovate in outline, 4–11 cm, glandular, many-spiculate; branches and pedicels filiform, flexuose; pedicels variable in length, shorter or longer than spikelets. Spikelets elliptic-globose, 1.5–2(–2.2) mm, greenish or purplish brown; florets slightly to clearly dissimilar; lower floret male, upper floret female; glumes subequal, as long as or shorter than florets, broadly elliptic, 5–7(–9)-veined, usually glabrous, rarely hispidulous or scaberulous above middle, apex broadly rounded; lower lemma oblong, cartilaginous to subcrustaceous, shallowly convex, back sometimes sulcate, smooth, glabrous; anthers 0.8–1.3 mm; upper lemma crustaceous, shorter and more convex, slightly rough, back glabrous or puberulous, upper margins ciliate. Fl. and fr. summer to autumn. 2n = 60.

Annuals, Terrestrial, not aquatic, Stems trailing, spreading or prostrate, Stems nodes swollen or brittle, Stems terete, round in cross section, or polygonal, Stems branching above base or distally at nodes, Stem nodes bearded or hairy, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath and blade differentiated, Leaf blades disarticulating from sheath, deciduous at ligule, Leaf blades lanceolate, Leaf blade auriculate, Leaf blades 2-10 mm wide, Leaf blades 1-2 cm wide, Leaf blades mostly flat, Leaf blades more or less hairy, Leaf blades glaucous, blue-green, or grey, or with white glands, Ligule present, Ligule a fringed, ciliate, or lobed membrane, Ligule a fringe of hairs, Inflorescence terminal, Inflorescence an open panicle, openly paniculate, branches spreading, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence branches more than 10 to numerous, Flowers bisexual, Flowers unisexual, Spikelets pedicellate, Spikelets sessile or subsessile, Spikelets dorsally compressed or terete, Spikelet less than 3 mm wide, Spikelets with 2 florets, Spikelets solitary at rachis nodes, Spikelets bisexual, Spikelets disarticulating above the glumes, glumes persistent, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes equal or subequal, Glumes equal to or longer than adjacent lemma, Glum es 3 nerved, Glumes 4-7 nerved, Glumes 8-15 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma similar in texture to glumes, Lemma 5-7 nerved, Lemma glabrous, Lemma body or surface hairy, Lemma apex truncate, rounded, or obtuse, Lemma awnless, Lemma margins thin, lying flat, Lemma straight, Palea present, well developed, Palea membranous, hyaline, Palea longer than lemma, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis.