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.

Chasmanthium

HABIT Perennial. Rhizomes short (4), or elongated (1). Culms erect (1/1), or geniculately ascending (1/1), or decumbent (1/1); slender (1/1); 30–88.5–150 cm long. Lateral branches lacking (2/2), or sparse (1/2). Ligule a ciliolate membrane (4), or a ciliate membrane (1). Leaf-blades linear (4), or lanceolate (1). Leaf-blade venation without cross veins (4), or with distinct cross veins (1).

INFLORESCENCE Inflorescence a panicle (4), or composed of racemes (1).

Panicle open (1/4), or contracted (3/4), or glomerate (1/4).

Racemes single (1/1), or borne along a central axis (1/1); spreading (1/1); bearing few fertile spikelets (1/1); bearing 2–12 fertile spikelets on each (1/1). Spikelet packing distant (1/1).

Spikelets appressed (1/2), or pendulous (1/2); solitary. Fertile spikelets sessile (3), or pedicelled (3).

FERTILE SPIKELETS Spikelets comprising 0 basal sterile florets (1), or 1 basal sterile florets (4), or 2 basal sterile florets (3), or 3–4 basal sterile florets (1); 1 fertile florets (1), or 2 fertile florets (4), or 3 fertile florets (3), or 4–11 fertile florets (2), or 12–24 fertile florets (1); with diminished florets at the apex. Spikelets elliptic (1), or oblong (1), or ovate (1), or obovate (1), or cuneate (3); laterally compressed; 4–14.4–40 mm long; breaking up at maturity; disarticulating below each fertile floret. Rhachilla internodes definite. Floret callus pilose (1/1).

GLUMES Glumes persistent; shorter than spikelet. Lower glume lanceolate (2), or ovate (3); 1 length of upper glume; chartaceous (1), or herbaceous (4); 1-keeled; 1–3 -veined (1/4), or 5–6 -veined (1/4), or 7 -veined (2/4), or 8 -veined (1/4), or 9 -veined (2/4), or 10–11 -veined (1/4). Lower glume lateral veins distinct (4), or prominent (1). Lower glume surface without pits. Lower glume apex acute (4), or acuminate (1). Upper glume lanceolate (1), or ovate (4); 0.33–0.4825–0.7 length of adjacent fertile lemma; chartaceous (1), or herbaceous (4); 1-keeled; 3 -veined (1/3), or 5–7 -veined (1/3), or 9–11 -veined (1/3). Upper glume apex acute (4), or acuminate (1).

FLORETS Basal sterile florets male (1), or barren (4); with palea (1), or without significant palea (4). Lemma of lower sterile floret elliptic (1), or ovate (4); chartaceous (1), or herbaceous (4); 3–5 -veined (1/3), or 7–8 -veined (1/3), or 9–11 -veined (2/3); acute. Fertile lemma lanceolate (1), or ovate (4); chartaceous (1), or herbaceous (4); keeled; wingless; 7–9 -veined (2), or 11–13 -veined (3), or 14–15 -veined (1). Lemma midvein without distinctive roughness (4), or scabrous (1); eciliate (4), or ciliolate (1). Lemma surface unwrinkled; without grooves. Lemma apex entire, or dentate (1); 2 -fid (1/1); acute (2), or acuminate (4). Palea embraced by lemma (3), or gaping (2); 0.8–0.9333–1 length of lemma; 2 -veined. Palea keels winged; smooth (4), or scabrous (1); eciliate (4), or ciliolate (1). Palea apex dentate (1/1). Apical sterile florets resembling fertile though underdeveloped (2), or distinct from fertile (3); 1 in number (1/1); male (1/1); linear (1/1).

FLOWER Lodicules 2; fleshy. Anthers 1 (4/4).

FRUIT Caryopsis with adherent pericarp; ovoid; laterally compressed (4/4). Embryo 0.5 length of caryopsis.

DISTRIBUTION North America.

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