Themeda quadrivalvis (L.) Kuntze

This species has dense fascicles of racemes similar to those of Themeda triandra, but with smaller spikelet parts and conspicuously setose homogamous spikelets with long, patent bristles from very large tubercles. It can also generally be separated by its annual habit.

Annual. Culms moderately robust, erect or geniculate at base, ca. 1 m tall. Leaf sheaths glabrous or with tubercle-based bristles at mouth; leaf blades flat or folded, up to 30 × 0.3–0.9 cm, glabrous, abruptly acute to acuminate; ligule ca. 3 mm. Compound panicle large, dense; spathes and spatheoles lanceolate-caudate, glabrous, innermost 1.3–1.7 cm. Raceme composed of a triad of 1 sessile and 2 pedicelled spikelets above the involucre of 2 homogamous pairs. Homogamous spikelets all sessile, arising at same level, barren, both glumes present, 4.5–6 mm, lanceolate, stiffly setose in upper half with 3–4 mm, tubercle-based bristles. Sessile spikelet 4–4.5 mm; callus 0.8–1 mm, subacute, brown bearded; lower glume dorsally rounded, dark brown at maturity, pubescent, often thinly or glabrous on lower back; awn 3.5–4 cm. Pedicelled spikelet 4–6 mm, barren. Fl. and fr. Jun–Dec.

Nepal, India.

Guangdong, Guangxi, Guizhou, Hainan, Yunnan [India, Indonesia, Myanmar, Nepal, Thailand, Vietnam; Australia].

600-3000 m

Dry hill slopes; 400–2000 m.

Andropogon quadrivalvis Linnaeus in Murray, Syst. Veg., ed. 13, 758. 1774; Themeda chinensis (A. Camus) S. L. Chen & T. D. Zhuang; T. ciliata (Linnaeus f.) Hackel subsp. chinensis A. Camus; T. echinata Keng; T. yuanmounensis S. L. Chen & T. D. Zhuang.

Themeda quadrivalvis (I^.) Kuntze, Rev. Gen. 794. 1891
Andropogon nutans L. Mant. 303. 1771. Not ^. nutans 1,, 1753. Andropogon quadrivalvis ,. Syst. Veg. ed. 13. 758. 1774. Anthisiiria ciliata I^. f. Suppl. 113. 1781. Themeda ciliata Hack, in DC. Monog. Phan. 6 : 664. 1889.
Annual. Stems up to 1 m. or more tall; leaf-sheaths glabrous; blades up to 3 dm. long, flat, linear, 4-6 mm. wide, glabrous; panicle usually composing more than one half of the stem ; spathes long-attenuate at the apex from a lanceolate base ; involucral spikelets 5-7 mm. long, the first scale papillose-ciliate on the keels with long stiff hairs; pedicellate spikelets lanceolate; sessile spikelets 5-6 mm. long, including the obtuse callus which is about 1 mm. long and densely barbed with brown hairs, the first scale hispid at the summit, the fourth scale with an awn 3-5 cm. long.
Type locality : India.
Distribution : Introduced into Martinique and Barbados ; native of the Hast Indies.

Annuals, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems erect or ascending, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stem internodes solid or spongy, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems with inflorescence 1-2 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaf tips flexuous, drooping, blades thin, lax, soft, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath smooth, glabrous, Leaf sheath or blade keeled, Leaf sheath and blade differentiated, Leaf sheath enlarged, inflated or distended, Leaf blades linear, Leaf blades 2-10 mm wide, Leaf blades mostly flat, Leaf blade margins folded, involute, or conduplicate, Leaf blades mostly glabrous, Ligule present, Ligule an unfringed eciliate membrane, Inflorescence terminal, Inflorescence lateral or axillary, Inflorescence racemose, Inflorescence an open panicle, openly paniculate, branches spreading, Inflorescence with 2 or more spikes, fascicles, glomerules, heads, or clusters per culm, Inflorescence lax, widely spreading, branches dr ooping, pendulous, Inflorescence a panicle with narrowly racemose or spicate branches, Inflorescence single raceme, fascicle or spike, Inflorescence with 2-10 branches, Flowers bisexual, Spikelets pedicellate, Spikelets dorsally compressed or terete, Inflorescence or spikelets partially hidden in leaf sheaths, subtended by spatheole, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets with 3-7 florets, Spikelets 3 per node, Spikelets bisexual, Spikelets disarticulating below the glumes, Spikelets falling with parts of disarticulating rachis or pedicel, Rachilla or pedicel glabrous, Glumes present, empty bracts, Glumes 2 clearly present, Glumes distinctly unequal, Glumes equal to or longer than adjacent lemma, Glume equal to or longer than spikelet, Glume surface hairy, villous or pilose, Glumes 3 nerved, Glumes 4-7 nerved, Lemmas thin, chartaceous, hyaline, cartilaginous, or membranous, Lemma 1 nerved, Lemma glabrous, Lemma apex acute or acuminate, Lemm a distinctly awned, more than 2-3 mm, Lemma with 1 awn, Lemma awn 2-4 cm long or longer, Lemma awned from tip, Lemma awn twisted, spirally coiled at base, like a corkscrew, Lemma awn once geniculate, bent once, Lemma margins thin, lying flat, Lemma straight, Callus or base of lemma evidently hairy, Callus hairs shorter than lemma, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.

Themeda quadrivalvis is a species of grass known by the common names grader grass, habana grass, and kangaroo grass, not to be confused with Themeda triandra, which is also known as kangaroo grass. It is native to India, Nepal, and Malaysia. It can also be found in many other places as an introduced species and often a noxious weed. It occurs in the United States, New Caledonia, Fiji, Mauritius, Thailand, Indonesia, Papua New Guinea, China, the Middle East and tropical America. It is a troublesome exotic weed in Australia, especially in northern regions. It is also an agricultural weed in crops such as sugar cane and lucerne.