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.

Rostraria

HABIT Annual. Culms erect, or geniculately ascending (9), or decumbent (1); 2.5–22.85–70 cm long. Lateral branches lacking (2/2), or sparse (1/2). Ligule an eciliate membrane. Leaf-blades linear, or lanceolate (1); firm (6), or flaccid (6).

INFLORESCENCE Inflorescence a panicle; exserted (11), or embraced at base by subtending leaf (1).

Panicle contracted (1), or spiciform (11).

Spikelets solitary. Fertile spikelets pedicelled. Pedicels oblong (9/9).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets (1), or 2 fertile florets (3), or 3 fertile florets (9), or 4 fertile florets (10), or 5 fertile florets (6), or 6 fertile florets (3), or 7–8 fertile florets (2); with a barren rhachilla extension (4), or with diminished florets at the apex (8). Spikelets oblong (10), or obovate (3), or cuneate (1); laterally compressed; 2.5–4.645–9 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite (11/11); glabrous (4/11), or pubescent (6/11), or pilose (1/11). Floret callus glabrous (1/2), or pubescent (1/2).

GLUMES Glumes persistent; shorter than spikelet (6), or reaching apex of florets (6), or exceeding apex of florets (2); gaping. Lower glume linear (1), or lanceolate (8), or elliptic (3); 0.25–0.7342–1 length of upper glume; membranous; without keels (6), or 1-keeled (6); 1 -veined (10), or 2 -veined (2), or 3 -veined (3). Lower glume lateral veins absent (10), or distinct (3). Lower glume surface without pits; glabrous (9), or puberulous (1), or pubescent (2), or pilose (1), or villous (1). Lower glume apex acute (5), or acuminate (5), or attenuate (2). Upper glume lanceolate (2), or elliptic (7), or oblong (1), or ovate (2); 0.75–0.9667–1.3 length of adjacent fertile lemma; membranous; with undifferentiated margins (11), or hyaline margins (1); without keels (4), or 1-keeled (8); 1 -veined (1), or 3 -veined (10), or 5 -veined (1). Upper glume primary vein eciliate (10), or ciliolate (3). Upper glume lateral veins without ribs (10/11), or ribbed (1/11). Upper glume surface glabrous (11), or puberulous (2), or pubescent (1), or pilose (1), or villous (1). Upper glume apex acute (9), or acuminate (2), or attenuate (1); muticous, or mucronate (1).

FLORETS Fertile lemma linear (1), or lanceolate (1), or elliptic (4), or oblong (4), or ovate (2), or obovate (1); oblong in profile (1/1); membranous; of similar consistency on margins (3), or much thinner on margins (9); without keel (1), or keeled (11); wingless; 3 -veined (3), or 4 -veined (1), or 5 -veined (10). Lemma midvein without distinctive roughness (10), or scaberulous (1), or scabrous (1); eciliate (11), or ciliate (1). Lemma lateral veins obscure (1/1); without ribs (10), or ribbed (2). Lemma surface smooth (11), or asperulous (1), or papillose (1), or tuberculate (1); unwrinkled; without grooves; glabrous (7), or pubescent (5), or pilose (1), or setose (1); with simple hairs (6/7), or tubercle-based hairs (1/7). Lemma apex entire (3), or dentate (9); 2 -fid (9/9); emarginate (1/11), or truncate (1/11), or obtuse (2/11), or acute (7/11), or setaceously attenuate (1/11); muticous (1), or mucronate (2), or awned (11); 1 -awned (11/11). Principal lemma awn apical (2), or subapical (6), or from a sinus (1), or dorsal (4); straight (11), or curved (1), or geniculate (1); 0.9–1–1.1 length of lemma. Palea gaping; 0.5–0.751–1 length of lemma; hyaline (9), or membranous (3). Palea keels smooth (3), or scaberulous (9). Palea apex dentate (1/1); muticous (10), or awned (2). Apical sterile florets resembling fertile though underdeveloped (8/8).

FLOWER Lodicules 2 (3/3); membranous (3/3). Anthers 3. Ovary glabrous.

FRUIT Caryopsis with adherent pericarp (2/2). Hilum punctiform (1/1).

DISTRIBUTION Europe (5), or Africa (8), or Temperate Asia (6), or Tropical Asia (3), or Australasia (3), or North America (1), or South America (2).

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