GrassBase - The Online World Grass Flora

Descriptions

W.D. Clayton, M. Vorontsova, K.T. Harman & H. Williamson

© Copyright The Board of Trustees, Royal Botanic Gardens, Kew.

Astrebla

HABIT Perennial. Rhizomes absent (1), or short (3). Culms erect, or geniculately ascending (1), or decumbent (1); 20–78.75–150 cm long. Ligule a ciliolate membrane (1), or a fringe of hairs (3).

INFLORESCENCE Inflorescence composed of racemes; exserted (2), or embraced at base by subtending leaf (2).

Racemes single, or paired (1); unilateral. Rhachis flattened. Spikelet packing broadside to rhachis; crowded (1), or contiguous (1), or lax (2); 2 -rowed.

Spikelets appressed (1/2), or pectinate (1/2); solitary. Fertile spikelets sessile (2), or pedicelled (3). Pedicels oblong (3/3).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets (1), or 2 fertile florets (3), or 3 fertile florets (2), or 4 fertile florets (3), or 5–6 fertile florets (1); with diminished florets at the apex. Spikelets elliptic (1), or oblong (2), or ovate (1); laterally compressed (3), or subterete (1); 7–12–20 mm long; breaking up at maturity; disarticulating above glumes but not between florets. Rhachilla internodes definite. Floret callus pubescent (1/2), or pilose (1/2).

GLUMES Glumes persistent; shorter than spikelet (3), or reaching apex of florets (1); thinner than fertile lemma. Lower glume linear (1), or lanceolate, or ovate (1); 0.5–0.765–1 length of upper glume; membranous (1), or chartaceous (2), or scarious (1); without keels (1), or 1-keeled (3); 1 -veined (3), or 2–4 -veined (2), or 5 -veined (3), or 6–9 -veined (1). Lower glume lateral veins absent (1), or distinct (3). Lower glume surface without pits. Lower glume apex acute (1), or acuminate (3); muticous (3), or mucronate (1). Upper glume lanceolate (2), or elliptic (1), or ovate (2); 0.66–0.9763–1.2 length of adjacent fertile lemma; membranous (1), or chartaceous (2), or scarious (1); with undifferentiated margins (3), or membranous margins (1); without keels; 7–8 -veined (3), or 9–11 -veined, or 12–13 -veined (2), or 14–16 -veined (1). Upper glume apex acute (1), or acuminate (3); muticous (3), or mucronate (1).

FLORETS Fertile lemma lanceolate (1), or oblong (3); coriaceous; much thinner above; without keel; wingless; 3 -veined. Lemma surface unwrinkled; without grooves; pubescent (2), or villous (2). Lemma apex lobed; 3 -fid; incised 0.25–0.5188–0.8 of lemma length; awned; 1 -awned (3), or 3 -awned (1). Principal lemma awn straight (3), or hooked (1). Lateral lemma awns shorter than principal (1/1). Palea 0.6–0.65–0.7 length of lemma. Palea keels pubescent (1), or ciliate (3). Palea apex lobed (1/1). Apical sterile florets resembling fertile though underdeveloped.

FLOWER Lodicules 2 (3/3); fleshy (3/3); truncate (3/3). Anthers 3.

FRUIT Caryopsis with adherent pericarp (3/3); ellipsoid (1/2), or oblong (1/2); dorsally compressed (1/1).

DISTRIBUTION Australasia.

Please cite this publication as detailed in How to Cite Version: 27th January 2014.