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.

Chaetium

HABIT Perennial. Culms erect (1/1); 30–66.66–120 cm long. Ligule a ciliolate membrane (1), or a ciliate membrane (1), or a fringe of hairs (1).

INFLORESCENCE Inflorescence composed of racemes.

Racemes borne along a central axis; erect; unilateral. Rhachis angular. Spikelet packing lax.

Spikelets in pairs. Fertile spikelets sessile and pedicelled (1), or pedicelled (2); 2 in the cluster.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate; dorsally compressed; plano-convex; 4–6.53–10 mm long; falling entire. Spikelet callus linear; pubescent (1), or pilose (2); base obtuse; attached obliquely.

GLUMES Glumes shorter than spikelet (1), or reaching apex of florets (2); thinner than fertile lemma. Lower glume subulate (1), or linear (1), or lanceolate (1); membranous (1/2), or herbaceous (1/2); without keels (2/2); 3 -veined (1/2), or 5–7 -veined (1/2). Lower glume surface smooth (2), or scabrous (1); without pits. Lower glume apex acuminate (1/1); awned (2/2). Upper glume lanceolate; hyaline (1), or membranous (1), or herbaceous (1); without keels; 3 -veined (1), or 5–6 -veined (1), or 7 -veined (2). Upper glume lateral veins without ribs (2), or ribbed (1). Upper glume surface asperulous (2), or scabrous (1). Upper glume apex acuminate (2/2); awned; 1 -awned.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret lanceolate (1), or oblong (1), or ovate (1); 1 length of fertile lemma; hyaline (1), or membranous (2); 3 -veined (1), or 5 -veined (2); without ribs (1), or ribbed (2); acute (2), or setaceously attenuate (1); muticous (2), or awned (1). Fertile lemma lanceolate (1), or elliptic (1), or ovate (1); coriaceous; without keel; wingless; 5 -veined (2/2). Lemma surface smooth (2), or scaberulous (1); unwrinkled; without grooves. Lemma margins involute. Lemma apex acute; muticous (1), or awned (2); 1 -awned (2/2). Palea not rolled (1), or involute (2); 1 length of lemma; coriaceous.

DISTRIBUTION North America (1), or South America.

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