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.

Psathyrostachys

HABIT Perennial. Rhizomes absent (7), or short (3), or elongated (1). Culms 15–49.45–110 cm long. Leaf-sheath auricles absent (6), or falcate (6). Ligule an eciliate membrane.

INFLORESCENCE Inflorescence composed of racemes.

Racemes single; linear (10), or oblong (3); bilateral. Rhachis fragile at the nodes. Spikelet packing broadside to rhachis (10/10). Rhachis internodes indefinite (1), or linear (2), or cuneate (8); falling with spikelet above (10/10).

Spikelets ascending (1/1); in pairs (4), or in threes. Fertile spikelets sessile; 2 in the cluster (4), or 3 in the cluster; subequal (5/7), or the central smaller (2/7).

FERTILE SPIKELETS Spikelets comprising 1 fertile florets, or 2 fertile florets (6), or 3 fertile florets (2); without rhachilla extension (1), or with a barren rhachilla extension (9), or with diminished florets at the apex (1). Spikelets lanceolate (10), or elliptic (1); dorsally compressed; 5.5–12.18–28 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pubescent (1/1). Rhachilla internodes brief up to lowest fertile floret (10), or elongated below proximal fertile floret (1); definite (6/6).

GLUMES Glumes collateral; reaching apex of florets (1), or exceeding apex of florets (10); gaping. Lower glume subulate; 1 length of upper glume. Lower glume surface smooth (5), or scabrous (6); without pits; glabrous (5), or puberulous (1), or pubescent (1), or pilose (6), or villous (1). Upper glume subulate. Upper glume surface smooth (5), or scabrous (6); glabrous (5), or puberulous (1), or pilose (6), or villous (1).

FLORETS Fertile lemma lanceolate; coriaceous; without keel; wingless; 5 -veined (1/9), or 7 -veined (8/9). Lemma midvein without distinctive roughness (10), or scabrous (1). Lemma lateral veins prominent (1/1). Lemma surface smooth (10), or scaberulous (1), or scabrous (1); unwrinkled; without grooves; glabrous (5), or puberulous (1), or pubescent (2), or pilose (6). Lemma margins eciliate (10), or ciliolate (1). Lemma apex entire (10), or lobed (1); 2 -fid (1/1); acuminate (10/10); awned; 1 -awned. Principal lemma awn apical (10), or from a sinus (1); straight (10), or curved (1); limb glabrous (10), or ciliate (1). Palea membranous (1), or coriaceous (10). Palea keels smooth (8), or scaberulous (2), or scabrous (1). Palea surface glabrous (9), or pubescent (1), or pilose (2). Apical sterile florets 1 in number (1/1); barren (1/1); linear (1/1).

FLOWER Anthers 3 (1/1). Ovary unappendaged (10), or beaked (1); pubescent on apex (10/10).

FRUIT Caryopsis with adherent pericarp (10/10). Hilum linear (10/10); 1 length of caryopsis.

DISTRIBUTION Europe (1), or Temperate Asia, or South America (1).

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