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.

Piptatherum

HABIT Perennial. Rhizomes absent (32), or short (2). Culms erect (18/22), or geniculately ascending (5/22), or decumbent (1/22); 8–56–150 cm long. Lateral branches lacking (1/1). Ligule an eciliate membrane. Leaf-blades filiform (3), or linear (31); herbaceous (30), or coriaceous (4); stiff (5), or firm (29).

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

Panicle open (26), or contracted (9). Primary panicle branches not whorled (33), or whorled at most nodes (1).

Spikelets solitary. Fertile spikelets pedicelled. Pedicels tip widened (2/2).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets; without rhachilla extension. Spikelets lanceolate (17), or elliptic (6), or oblong (2), or ovate (13); dorsally compressed; 2.49–6.476–12 mm long; breaking up at maturity; disarticulating below each fertile floret. Floret callus glabrous (16/16).

GLUMES Glumes persistent; shorter than spikelet (1), or reaching apex of florets (1), or exceeding apex of florets (32); thinner than fertile lemma. Lower glume lanceolate (2), or elliptic (15), or oblong (1), or ovate (16); 1–1.007–1.2 length of upper glume; hyaline (1), or membranous (32), or herbaceous (1); without keels; 1–6–9 -veined. Lower glume lateral veins absent (1), or obscure (1), or distinct (32). Lower glume surface smooth (30), or asperulous (2), or scabrous (2); without pits. Lower glume apex entire (33), or dentate (1); 2 -fid (1/1); obtuse (2/33), or acute (17/33), or acuminate (16/33). Upper glume lanceolate (2), or elliptic (15), or oblong (1), or ovate (16); 0.9–1.483–2 length of adjacent fertile lemma; hyaline (2), or membranous (31), or herbaceous (1); with undifferentiated margins (32), or hyaline margins (2); without keels; 1 -veined (2/24), or 2 -veined (1/24), or 3 -veined (9/24), or 4 -veined (3/24), or 5 -veined (15/24), or 6–7 -veined (7/24), or 8–9 -veined (2/24). Upper glume surface smooth (30), or asperulous (2), or scabrous (2). Upper glume apex obtuse (2), or acute (18), or acuminate (16).

FLORETS Fertile lemma linear (4), or lanceolate (11), or elliptic (12), or oblong (3), or ovate (11), or obovate (1); dorsally compressed; coriaceous (33), or indurate (1); without keel; wingless; 3 -veined (3/5), or 5 -veined (2/5). Lemma surface unwrinkled; without grooves; glabrous (8), or puberulous (2), or pubescent (19), or pilose (4), or villous (1); without hair tufts (32), or with basal hair tufts near margin (2), or with conspicuous apical hairs (1). Lemma margins involute; exposing palea (33), or covering most of palea (1). Lemma apex entire (31), or dentate (3); 2 -fid (3/3); obtuse (21/29), or acute (7/29), or rostrate (1/29); without ornament, or pubescent (1); muticous (1), or awned (33); 1 -awned (33/33). Principal lemma awn apical (31/33), or subapical (2/33); straight (24/33), or curved (5/33), or flexuous (4/33), or bigeniculate (1/33). Palea 1 length of lemma; membranous (1), or coriaceous (32), or indurate (1); 2 -veined (33/33); without keels (33), or 2-keeled (1).

FLOWER Lodicules 2 (1/18), or 3 (17/18). Anthers 3 (27/27).

FRUIT Caryopsis with adherent pericarp (27/27); fusiform (1/15), or ellipsoid (10/15), or oblong (2/15), or ovoid (1/15), or obovoid (2/15); isodiametric (1/1). Embryo 0.25–0.3167–0.5 length of caryopsis. Hilum linear (14/14); 0.8–0.8938–0.9 length of caryopsis.

DISTRIBUTION Europe (5), or Africa (4), or Temperate Asia (29), or Tropical Asia (7), or Australasia (1), or Pacific (1), or North America (4), or South America (1).

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