Pennisetum pedicellatum

Name and classification

Pennisetum pedicellatum Trin.
Family Poaceae, Tribe Paniceae

Common names

kyasuma grass, kyasuwa grass, hairy fountaingrass

Disseminule

fertile floret, or fascicle consisting of bristles enclosing 1–3(5) spikelets; disarticulation below fascicle and at base of fertile florets

Description

Fascicle consists of unfused bristles; outer bristles 10–20, 1.2–2 mm long, antrorsely scabrous; inner bristles 40–90, 2.2–14 mm long, long ciliate; primary bristle solitary, conspicuously longer than other bristles, to 25 mm, long ciliate. Spikelet cluster of 1 sessile and usually at least 1 pedicellate spikelet; pedicels 0.5–3.5 mm long. Spikelets lanceolate, slightly dorsally compressed, 3.4–6 mm long, 0.6–1 mm wide; consisting of 1 fertile floret and 1 basal sterile floret. Glumes hyaline to membranous; lower glume reduced or absent; upper glume as long as spikelet. Bracts of sterile floret membranous; sterile lemma trilobed, 3.1–4.0 mm long; sterile palea 2.5–3.5 mm long. Fertile floret lanceolate, 2–3 mm long, 0.6–1 mm wide; fertile lemma and palea coriaceous, glossy, translucent, and ciliate at apices. Caryopsis lanceolate, dorsally compressed, 0.5–2.5 mm long, golden brown.

Identification considerations

Pennisetum pedicellatum belongs to a unique section of the genus with a trilobed sterile lemma. Pennisetum pedicellatum spikelets are in clusters of 1–3(5) in the fascicle, lower glume length is at least 50% of spikelet. See

Pennisetum clandestinum Hochst. ex Chiov.

Pennisetum macrourum Trin.

Pennisetum polystachion (L.) Schultes.

Distribution

tropical Africa, South Africa, Asia (India, Malaysia, Philippines, Thailand), Australia, Fiji, United States

Habitat

drier sites, savannahs and woodland margins; a weed in croplands, grasslands, waste places

General information

Pennisetum pedicellatum is an erect or geniculate annual or perennial grass, to 150 cm tall. It has been introduced as a pasture grass in Asia, Australia and the Americas. However, it invades croplands and cleared lands, and is difficult to eradicate.

fascicles of bristles enclosing one or more spikelets each

fascicles of bristles enclosing one or more spikelets each

florets in dorsal view showing lemma (top) and ventral view showing palea (bottom)

florets in dorsal view showing lemma (top) and ventral view showing palea (bottom)

caryopses in ventral view (left) and dorsal view (right)

caryopses in ventral view (left) and dorsal view (right)

A, fascicle of bristles enclosing spikelet(s); B, cluster of two spikelets in fascicle (some bristles removed); C–D, floret in two views; E, caryopsis in ventral view; F, caryopsis in dorsal view; drawing by Lynda E. Chandler

A, fascicle of bristles enclosing spikelet(s); B, cluster of two spikelets in fascicle (some bristles removed); C–D, floret in two views; E, caryopsis in ventral view; F, caryopsis in dorsal view; drawing by Lynda E. Chandler