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.

Imperata

HABIT Perennial. Rhizomes absent (3), or elongated (8). Culms erect (9/10), or geniculately ascending (2/10), or decumbent (1/10); 10–87.59–200 cm long. Lateral branches lacking (6/6). Leaf-sheath auricles absent (10), or erect (2). Ligule an eciliate membrane (3), or a ciliolate membrane (6), or a ciliate membrane (2). Leaf-blades linear, or lanceolate (1); herbaceous (10), or coriaceous (1); stiff (8), or firm (3). Leaf-blade midrib conspicuous (1/2), or widened (1/2).

INFLORESCENCE Inflorescence a panicle with branches tipped by a raceme; exserted (10), or embraced at base by subtending leaf (1).

Panicle contracted (2), or spiciform (10).

Racemes bearing few fertile spikelets. Rhachis subterete (10/10). Rhachis internodes filiform.

Spikelets in pairs. Fertile spikelets pedicelled; 2 in the cluster. Pedicels filiform (10), or clavate (1); tip widened (1/5), or discoid (4/5).

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate (6), or elliptic (5), or oblong (1); subterete; 1.5–3.339–6 mm long; falling entire. Spikelet callus bearded; base truncate.

GLUMES Glumes exceeding apex of florets; firmer than fertile lemma. Lower glume lanceolate (9), or oblong (2); membranous; without keels; 3 -veined (5/10), or 4 -veined (3/10), or 5 -veined (7/10), or 6–7 -veined (1/10). Lower glume lateral veins obscure (1), or distinct (10). Lower glume surface smooth, or asperulous (1); without pits; glabrous (1), or pilose (1), or villous (9). Lower glume apex obtuse (2/3), or acuminate (1/3). Upper glume lanceolate (9), or oblong (2); membranous; with undifferentiated margins (10), or hyaline margins (1); without keels; 3 -veined (5/10), or 5 -veined (4/10), or 6 -veined (3/10), or 7 -veined (4/10). Upper glume surface smooth, or scabrous (1); glabrous (1), or pilose (1), or villous (9). Upper glume apex obtuse (1/3), or acute (1/3), or acuminate (1/3).

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret linear (1), or oblong (10); hyaline; 0 -veined (9/10), or 1 -veined (1/10); obtuse (8/9), or acuminate (1/9). Fertile lemma linear (1), or ovate (10); hyaline; without keel; wingless; 0 -veined (10), or 1 -veined (1). Lemma surface unwrinkled; without grooves; glabrous (10), or puberulous (1). Lemma margins eciliate (10), or ciliate (1). Lemma apex entire (7), or erose (2), or dentate (2); 3 -fid (2/2); obtuse (1/5), or acute (4/5). Palea 0.5 length of lemma; hyaline (9), or membranous (2); 0 -veined (9/9); without keels (9), or 2-keeled (2).

FLOWER Lodicules absent (10), or 2 (1). Anthers 1 (7/10), or 2 (3/10). Stigmas 2.

FRUIT Caryopsis with adherent pericarp (2/2); obovoid (1/1).

DISTRIBUTION Europe (1), or Africa (1), or Temperate Asia (3), or Tropical Asia (2), or Australasia (2), or Pacific (2), or North America (4), or South America (6).

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