Brownbeard Rice

This is a member of the AA genome complex, which includes cultivated rice, of which it is a progenitor. Members of this group hybridize quite easily and have contributed to the development of rice cultivars. Oryza rufipogon is perennial, but the most important difference from cultivated rice is the possession of readily deciduous spikelets.

Perennial, aquatic, tufted or stoloniferous. Culms decumbent, rooting and tillering at nodes, sometimes floating, lower part spongy, 0.7–1.5 m or more tall. Leaf sheaths slightly inflated below, upper sheaths tight, glabrous, auricles conspicuous, glabrous or ciliate; leaf blades up to 40 × 1–2 cm, margins and midrib scabrid, apex acuminate; ligule up to 17 mm. Panicle spreading, 12–30 cm, eventually nodding; branches 1–5 at lowest node, longest 2.5–12 cm, axils bearded or glabrous. Spikelets oblong, 8–11 mm, length 2.7–4.5 times width, yellowish green with reddish apex, deciduous; sterile lemmas lanceolate, ca. 2.5 mm, apex acuminate; fertile lemma finely reticulate with scattered short glassy hairs, flanks slightly sulcate, keel stiffly ciliate, apex acuminate; awn 5–40 mm or more, stout, scaberulous. Anthers 4–6 mm. Caryopsis reddish brown, 5–7 mm. Fl. and fr. Apr–May and Oct–Nov. 2n = 24.

Nepal, E. India, Madras.

Guangdong, Guangxi, Hainan, Taiwan, Yunnan [Bangladesh, Cambodia, India, Indonesia, Malaysia, Myanmar, New Guinea, Sri Lanka, Philippines, Thailand, Vietnam; Australia (Queensland)].

600 m

Riversides, ponds, streams, lotus ponds, rice fields, ditches, marshes; below 700 m.

Oryza sativa Linnaeus subsp. rufipogon (Griffith) de Wet; O. sativa var. rufipogon (Griffith) G. Watt.

Perennials, Aquatic, leaves emergent, Aquatic, fresh water, Terrestrial, not aquatic, Rhizomes present, Rhizome elongate, creeping, stems distant, Stems nodes swollen or brittle, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems solitary, Stems terete, round in cross section, or polygonal, Stems branching above base or distally at nodes, Stem internodes solid or spongy, Stems with inflorescence less than 1 m tall, Stems with inflorescence 1-2 m tall, Stems with inflorescence 2-6 m tall, Stems, culms, or scap es exceeding basal leaves, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath and blade differentiated, Leaf blades linear, Leaf blade auriculate, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Leaf blades scabrous, roughened, or wrinkled, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence an open panicle, openly paniculate, branches spreading, Inflorescence a contracted panicle, narrowly paniculate, branches appressed or ascending, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence with 2-10 branches, Flowers bisexual, Spikelets pedicellate, Spikelets laterally compressed, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets with 3-7 florets, Spikelet with 1 fertile floret and 1-2 sterile florets, Spikelets solitary at rachis nodes, Spikelets all alike and fertille, Spikelets bisexual, Spikelets disarticulating below the glumes, Rachilla or pedicel glabrous, Glumes minute, much smaller than lemmas, Lemma coriaceous, firmer or thicker in texture than the glumes, Lemma becoming indurate, enclosing palea and caryopsis, Lemma 5-7 nerved, Lemma 8-15 nerved, Lemma body or surface hairy, Lemma rugose, with cross wrinkles, or roughened, Lemma apex acute or acuminate, Lemma distinctly awned, more than 2-3 mm, Lemma with 1 awn, Lemma awn 2-4 cm long or longer, Lemma awned from tip, Lemma awns straight or curved to base, Lemma margins inrolled, tightly covering palea and caryopsis, Lemma straight, Lemma surface pilose, setose or bristly, Palea present, well developed, Palea about equal to lemma, Stamens 6, Styles 1, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.

Oryza rufipogon, known as brownbeard rice, wild rice, and red rice, is a member of the genus Oryza.

It is native to East, Southeast and South Asia. It has a close evolutionary relation to Oryza sativa, the plant grown as a major rice food crop throughout the world. Both have an AA genome.

Oryza glumaepatula is a related species according to molecular biology approaches. It used to be considered a synonym referring to the South American race of O. rufipogon.