Leptochloa chinensis

Name and classification

Leptochloa chinensis (L.) Nees
Family Poaceae, Tribe Chlorideae

Common names

Asian sprangletop

Disseminule

floret or caryopsis; disarticulation above the glumes and between the florets

Description

Spikelets laterally compressed, 2–3.7(4.2) mm long, 0.75–1.3 mm wide, of 5–6 fertile florets, rachilla elongated between florets. Glumes hyaline to membranous, keeled, keels minutely barbed, lower glume usually shorter than upper glume. Floret dorsally compressed, elliptic, with narrow rachilla fragment ca. 0.3 mm long. Lemma (0.8)1.2–1.7(1.85) mm long, membranous to hyaline, keeled, palea twice keeled, both lemma and palea glabrous to hairy on surface, keels +/– hairy and minutely barbed. Caryopsis obovate, dorsally compressed, reddish-brown, 0.5–1.9 mm long, surface striate; embryo large; hilum small, round, indented.

Identification considerations

The dorsally compressed caryopses flattened on one face is a characteristic that may help to distinguish Leptochloa chinensis from other Leptochloa species.

Similar species

Leptochloa panicea (Retz.) Ohwi ssp. brachiata (Steud.) N. Snow (non-FNW)

Distribution

southeastern Africa, from Kenya to South Africa; Asia, from India and Sri Lanka to Southeast Asia, also China, Japan, and Korea; Australia, New Guinea

native to tropical Asia

Habitat

wet, swampy or marshy sites; streams, ditches, grasslands, drains

General information

Leptochloa chinensis is an annual or short-lived perennial grass, to 100 cm tall. This grass has become a serious weed in rice fields in Asian countries; it can grow profusely if waterlogged or flooded. The grains are much smaller than rice grains and can be removed during cleaning. Propagation is by grains or by stolons. Leptochloa chinensis has been used for fodder, and as a famine food in East Africa.

A–B, spikelets; A, with glumes; B, without glumes; C–G, florets; C,E,F, ventral view showing palea and rachilla; D,G, dorsal view showing lemma; H, caryopsis

A–B, spikelets; A, with glumes; B, without glumes; C–G, florets; C,E,F, ventral view showing palea and rachilla; D,G, dorsal view showing lemma; H, caryopsis

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

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

caryopses in ventral view (A,C) and dorsal view (B,D)

caryopses in ventral view (A,C) and dorsal view (B,D)

A, spikelet; B, floret in side view; C, floret in ventral view; D, caryopsis in side view; E, caryopsis in dorsal view; drawing by Lynda E. Chandler

A, spikelet; B, floret in side view; C, floret in ventral view; D, caryopsis in side view; E, caryopsis in dorsal view; drawing by Lynda E. Chandler

portion of inflorescence; photo by Mark Thurmond

portion of inflorescence; photo by Mark Thurmond