Hilaria

HABIT Annual (1), or perennial (9). Rhizomes absent (7), or short (2), or elongated (1). Stolons absent (4), or present (6). Culms erect (9), or geniculately ascending (1), or decumbent (1); slender (1/1); 5–35.5–100 cm long; rooting from lower nodes (1/1). Lateral branches ample (1/1). Ligule an eciliate membrane (9), or a ciliolate membrane (1). Leaf-blades herbaceous (9), or coriaceous (1); stiff (4), or firm (6). Leaf-blade apex muticous (9), or pungent (1).

INFLORESCENCE Inflorescence composed of racemes.

Racemes borne along a central axis; in a multilateral false spike; oblong (3), or cuneate (7); unilateral; bearing a triad of spikelets. Central inflorescence axis unspecialized (8), or flattened (2). Rhachis obsolete; deciduous from axis.

Spikelets in threes. Fertile spikelets sessile (9), or pedicelled (1); 1 in the cluster. Companion sterile spikelets sessile (9), or pedicelled (1); 2 in the cluster.

STERILE SPIKELETS Companion sterile spikelets well-developed; deciduous with the fertile. Companion sterile spikelet glumes muticous (5), or mucronate (1), or awned (4).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate (1), or oblong (9); laterally compressed; 3–6.3–12 mm long; falling entire; deciduous with accessory branch structures.

GLUMES Glumes free (3), or connate along margins below (7); shorter than spikelet; similar to fertile lemma in texture (5), or firmer than fertile lemma (5). Lower glume lanceolate (1), or oblong (8), or ovate (1); 0.5–0.6667–1 length of upper glume; membranous (2), or chartaceous (1), or coriaceous (7); 1-keeled; 3 -veined (1), or 7 -veined (9). Lower glume surface smooth (6), or scabrous (3), or tuberculate (1); without pits; glabrous (9), or pubescent (1). Lower glume apex lobed; 2 -fid (8), or 3 -fid (1), or 5 -fid (2); truncate (1/1), or obtuse (1/1); awned. Upper glume lanceolate (1), or oblong (8), or ovate (1); 0.6–0.7958–1 length of adjacent fertile lemma; membranous (2), or chartaceous (1), or coriaceous (7); with undifferentiated margins (9), or membranous margins (1); 1-keeled; 5 -veined (1), or 7 -veined (9). Upper glume primary vein eciliate (9), or ciliate (1). Upper glume surface smooth (6), or scabrous (3), or tuberculate (1); glabrous (9), or puberulous (1). Upper glume apex lobed; 2 -fid (8), or 3 -fid (1), or 5 -fid (2); truncate (1/1), or obtuse (1/1); awned; 1 -awned (7), or 2–3 -awned (2), or 7 -awned (2). Upper glume awn terminal (9), or dorsal (2).

FLORETS Fertile florets bisexual (4), or female (6). Fertile lemma lanceolate (3), or ovate (7); laterally compressed; membranous (1), or cartilaginous (9); keeled; wingless; 3 -veined. Lemma surface unwrinkled; without grooves. Lemma apex entire (7), or dentate (2), or lobed (1); 2 -fid (3/3); incised 0.25 of lemma length; obtuse (2), or acute (1), or caudate (7); muticous (7), or mucronate (1), or awned (3); 1 -awned (3/3). Principal lemma awn from a sinus (3/3).

FLOWER Lodicules 2 (3/3). Anthers 3.

FRUIT Embryo 1 length of caryopsis.

DISTRIBUTION North America, or South America (1).

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