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.

Danthonia

HABIT Perennial. Rhizomes absent (18), or short (7), or elongated (1). Culms erect (16/18), or geniculately ascending (4/18), or decumbent (2/18); slender (1/1); 4–38.79–100 cm long. Lateral branches lacking (3/3). Ligule a fringe of hairs. Leaf-blades persistent (24), or deciduous at the ligule (1); filiform (9), or linear (17); stiff (1), or firm (24).

INFLORESCENCE Inflorescence a panicle (22), or comprising only a few spikelets (6).

Panicle open (18/22), or contracted (6/22).

Spikelets appressed (2/3), or ascending (1/3), or spreading (1/3), or deflexed (1/3); solitary, or in pairs (1). Fertile spikelets pedicelled.

FERTILE SPIKELETS Spikelets comprising 2–5–10 fertile florets; with diminished florets at the apex. Spikelets lanceolate (1), or elliptic (22), or oblong (1), or cuneate (2); laterally compressed; 6.5–15.72–30 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite. Floret callus brief (2), or evident (23); pubescent (11), or pilose (14), or bearded (3); truncate (1), or obtuse.

GLUMES Glumes persistent; shorter than spikelet (2), or reaching apex of florets (6), or exceeding apex of florets (19); thinner than fertile lemma; parallel to lemmas (24), or gaping (1). Lower glume linear (4), or lanceolate (22), or ovate (1); 0.8–1–1.2 length of upper glume; membranous; without keels (24), or 1-keeled (1); 3 -veined (20), or 4 -veined (11), or 5 -veined (16), or 6–7 -veined (6). Lower glume lateral veins obscure (2), or distinct (23). Lower glume surface smooth, or asperulous (1); without pits. Lower glume apex obtuse (1), or acute (6), or acuminate (19), or attenuate (1). Upper glume linear (4), or lanceolate (22), or ovate (1); 0.75–2.179–7 length of adjacent fertile lemma; membranous; with undifferentiated margins (22), or hyaline margins (3); without keels (24), or 1-keeled (1); 3 -veined (16), or 4 -veined (8), or 5 -veined (15), or 6 -veined (4), or 7 -veined (6). Upper glume lateral veins with cross-veins (1/1). Upper glume surface smooth, or asperulous (1). Upper glume apex obtuse (1), or acute (6), or acuminate (19), or attenuate (1).

FLORETS Fertile lemma elliptic (22), or oblong (2), or ovate (3); chartaceous (19), or coriaceous (6); of similar consistency on margins (23), or much thinner on margins (2); without keel; wingless; 5 -veined (13/21), or 7 -veined (4/21), or 8 -veined (3/21), or 9 -veined (7/21), or 10–11 -veined (1/21). Lemma midvein eciliate (24), or ciliate (1). Lemma surface unwrinkled; without grooves; glabrous (10), or pubescent (4), or pilose (11); without hair tufts (23), or with marginal hair tufts (2). Lemma margins eciliate (7), or ciliolate (4), or ciliate (14), or pubescent (1). Lemma apex dentate (1), or lobed (24); 2 -fid; incised 0.25–0.4233–0.66 of lemma length; acute (1/2), or acuminate (1/2); mucronate (1), or awned (24); 1 -awned (4/24), or 3 -awned (20/24). Principal lemma awn from a sinus; straight (1), or curved (1), or geniculate (23). Lateral lemma awns shorter than principal (18/18). Palea 0.5–0.8333–1 length of lemma; 2 -veined (24/24). Palea keels wingless (22), or winged (3); smooth (23), or scaberulous (1), or scabrous (1); eciliate (9), or ciliolate (16). Palea surface glabrous (20), or pubescent (1), or pilose (4). Apical sterile florets resembling fertile though underdeveloped (24), or distinct from fertile (1); 1 in number (1/1); barren (1/1); rudimentary (1/1).

FLOWER Lodicules 2; fleshy; glabrous (23), or ciliate (5); truncate (1/1). Anthers 3.

FRUIT Caryopsis with adherent pericarp; ellipsoid (6/8), or ovoid (1/8), or obovoid (1/8). Embryo 0.33–0.4263–0.5 length of caryopsis. Hilum elliptic (2/24), or linear (22/24); 0.2–0.2883–0.33 length of caryopsis.

CLEISTOGENES AND VIVIPARY Cleistogenes absent (6), or present (19); in upper sheaths (2/19), or in lower sheaths (18/19).

DISTRIBUTION Europe (2), or Africa (1), or Temperate Asia (3), or Australasia (1), or North America (10), or South America (16).

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