Diarrhena

HABIT Perennial. Rhizomes short (3), or elongated (2). Culms erect, or geniculately ascending (1); slender (1/1); 48–80.9–131 cm long. Lateral branches lacking (1/1). Ligule an eciliate membrane (4), or a ciliolate membrane (1). Leaf-blades linear (3), or lanceolate (4). Leaf-blade venation without cross veins (1), or with obscure cross veins (1), or with distinct cross veins (3).

INFLORESCENCE Inflorescence a panicle.

Panicle open (3), or contracted (2).

Spikelets solitary. Fertile spikelets pedicelled. Pedicels filiform (1/1).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets (2), or 2–3 fertile florets (4), or 4–5 fertile florets (2), or 6–7 fertile florets (1); without rhachilla extension (3), or with diminished florets at the apex (2). Spikelets oblong (2), or ovate (1), or obovate (3); laterally compressed; 3–8.2–18 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite; glabrous (4), or pubescent (1). Floret callus glabrous (1/1).

GLUMES Glumes persistent; shorter than spikelet. Lower glume lanceolate; 0.33–0.575–0.75 length of upper glume; membranous (3), or cartilaginous (2); 1-keeled; 1 -veined, or 2–3 -veined (1). Lower glume lateral veins absent, or distinct (1). Lower glume surface without pits. Lower glume apex acute. Upper glume lanceolate (4), or ovate (2); 0.3–0.542–0.7 length of adjacent fertile lemma; membranous (3), or cartilaginous (2); 1-keeled; 1 -veined (3), or 2 -veined (1), or 3 -veined (3), or 4–5 -veined (2). Upper glume apex acute.

FLORETS Fertile lemma lanceolate (2), or elliptic (2), or ovate (4); chartaceous (1), or herbaceous (1), or cartilaginous (3); of similar consistency on margins (3), or much thinner on margins (2); without keel; wingless; 3 -veined, or 4–5 -veined (1). Lemma lateral veins with distinct primaries but obscure intermediates (1/2), or prominent (1/2). Lemma surface smooth (4), or scabrous (1); unwrinkled; without grooves. Lemma apex obtuse (2), or acute (1), or cuspidate (2); muticous (4), or awned (1); 1 -awned (1/1). Principal lemma awn pungent (1/1). Palea 2 -veined. Palea keels smooth (4), or scabrous (1); eciliate (4), or ciliolate (1). Palea apex dentate (1/1). Apical sterile florets resembling fertile though underdeveloped (2/2).

FLOWER Lodicules 2; membranous. Anthers 2 (1/4), or 3 (4/4).

FRUIT Caryopsis with tardily free pericarp; ellipsoid, or obovoid (4); apex umbonate.

DISTRIBUTION Temperate Asia (3), or North America (2).

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.