Bothriochloa ischaemum

HABIT Perennial; caespitose. Rootstock evident. Culms erect, or geniculately ascending; 40–80 cm long. Leaves mostly basal. Ligule a ciliolate membrane. Leaf-blades 3–15 cm long; 2–4 mm wide; glaucous. Leaf-blade surface scaberulous. Leaf-blade margins tuberculate-ciliate; hairy at base.

INFLORESCENCE Inflorescence composed of racemes.

Racemes 5–15; digitate; 4–6 cm long. Rhachis fragile at the nodes; flattened; villous on margins. Rhachis internodes linear. Rhachis internode tip transverse.

Spikelets in pairs. Fertile spikelets sessile; 1 in the cluster. Companion sterile spikelets pedicelled; 1 in the cluster. Pedicels linear; flattened; with a translucent median line (also present in internodes); villous.

STERILE SPIKELETS Companion sterile spikelets well-developed; containing empty lemmas, or male; lanceolate; 3.5–5 mm long; as long as fertile. Companion sterile spikelet glumes without depressions; glabrous. Companion sterile spikelet lemmas enclosed by glumes.

FERTILE SPIKELETS Spikelets comprising 1 basal sterile florets; 1 fertile florets; without rhachilla extension. Spikelets lanceolate, or oblong; dorsally compressed; 3.5–5 mm long; falling entire; deciduous with accessory branch structures. Spikelet callus pilose; base obtuse; attached transversely.

GLUMES Glumes dissimilar; exceeding apex of florets; firmer than fertile lemma. Lower glume elliptic; 1 length of spikelet; chartaceous; without keels; keel-less except near apex. Lower glume surface flat; without pits; pilose; hairy below. Lower glume apex acute. Upper glume lanceolate; 1-keeled.

FLORETS Basal sterile florets barren; without significant palea. Lemma of lower sterile floret oblong; hyaline. Fertile lemma linear; hyaline; without keel. Lemma apex entire; awned; 1 -awned. Principal lemma awn apical; geniculate; 12–15 mm long overall; with twisted column. Column of lemma awn glabrous. Palea absent or minute.

FLOWER Anthers 3.

DISTRIBUTION Europe: central, southwestern, southeastern, and eastern. Africa: north and Macaronesia. Asia-temperate: Siberia, Soviet Middle Asia, Caucasus, western Asia, China, and eastern Asia. Asia-tropical: India, Malesia, and Papuasia. Pacific: south-central. North America: north-central USA, south-central USA, southeast USA, and Mexico. South America: Caribbean, northern South America, and western South America.

NOTES Andropogoneae. Fl Pak 1993.

Please cite this publication as detailed in How to Cite Version: 3rd February 2016.