5. Oryza glaberrima Steudel, Syn. Pl. Glumac. 1: 3. 1853.
光稃稻 guang fu dao
Annual. Culms erect, spongy, up to 1 m tall. Leaf sheaths glabrous, leaf blades up to 30 × 1–1.5 cm, glabrous, margins scabrid; ligule 3–5 mm. Panicle loosely contracted, 20–25 cm; branches long, mostly simple. Spikelets obliquely inserted on pedicels, oblong, 7–9 mm, length twice width, yellow or dark brown, persistent; sterile lemmas lanceolate, 1.5–3 mm, margins sparsely ciliate, apex acuminate; fertile lemma smooth, glabrous or keel ciliate, apex with acute beak, usually awnless. Anthers ca. 1.5 mm. Caryopsis oblong, 5–6 mm. 2n = 24.
Cultivated, in flooded fields. Hainan, Yunnan [domesticated in W tropical Africa].
This African rice is the other cultivated species in Oryza, but its cultivation is much less widespread than that of O. sativa. It belongs to the AA genome complex, but can be clearly distinguished from O. sativa and others of this complex in China by its much shorter, rounded ligule.