Mexican Panicgrass

Panicum sonorum Beal, Grasses N. Am. 2: 130. 1896
Panicum capillare miliaceum Vasey; Vasey & Rose, Contr. U. S. Nat. Herb. 1: 28. 1890. Not P. miliaceum L. 1753.
Plants robust, erect or spreading, 60 cm. to more than 1 meter high; culms glabrous or
sparsely papillose-hispid, the nodes pubescent; leaf -sheaths papillose-hispid or nearly glabrous;
blades 15-40 cm. long, 15-30 mm. wide, cordate-clasping at base, rather prominently nerved,
glabrous or sparsely papillose-hispid; panicles large and more or less drooping, 2O--30 cm. long,
densely flowered, the numerous branches narrowly ascending; spikelets 3-3.3 mm. long, 1,1 mm.
wide, lanceolate, strongly nerved, brownish; first glume half to two thirds the length of the
spikelet, acuminate ; second glume slightly exceeding the sterile lemma, the palea of the sterile
floret wanting; fruit 2.1 mm. long, 1 mm. wide, oblong-obovate, subacute. This species may
be a cultivated form of Panicum hirticaule.
Type locality: Lerdo, Sonora. Distribution: Northwestern Mexico; Chiapas.

Panicum hirticaule J. Presl, in Presl, Rel. Haenk. 1: 308. 1830
Panicum Jlabellatum Fourn. Bull. Soc. Bot. Fr. 27: 293. 1881. Not P. fldbellatum Steud. 1854. Panicum polygamum hirticaule Fourn. Mex. PI. Gram. 28. 1886.
Plants erect, simple or nearly so, or sometimes branching and decumbent at base, 15-70 cm. high; culms papillose-hispid to glabrous, the nodes spreading-hispid ; leaf-sheaths papillosehispid, but sometimes sparsely so; blades 5-15 cm. long, 4—13 mm. wide, often cordate at base, sparsely hispid or nearly glabrous, ciliate toward the base; panicles exserted, 5-15 cm. long, scarcely one third the entire height of the plant, rather many-flowered, the branches ascending, the lower usually narrowly so, scabrous but not pilose, bearing rather short and appressedpediceled spikelets along half to two thirds their length, the glabrous pulvini inconspicuous; spikelets 2.7-3.3 mm. long, 1-1.1 mm. wide (smaller in occasional specimens), lanceolatefusiform, acuminate, typically reddish-brown; first glume half to three fourths the length of the spikelet, acuminate, the midnerve scabrous toward the apex; second glume slightly longer than the sterile lemma, both much exceeding the fruit, strongly many-nerved, the midnerves scabrous toward the summit, the palea of the sterile floret small, nerveless; fruit 2 mm. long, 1 mm. wide, elliptic, a scar sometimes showing on either side at base.
Type locality: Acapulco, Guerrero.
Distribution: Texas to southern California, and south through Mexico to northern South

Annuals, Terrestrial, not aquatic, Stems nodes swollen or brittle, Stems erect or ascend ing, Stems geniculate, decumbent, or lax, sometimes rooting at nodes, Stems caespitose, tufted, or clustered, Stems terete, round in cross section, or polygonal, Stems branching above base or distally at nodes, Stem internodes hollow, Stems with inflorescence less than 1 m tall, Stems, culms, or scapes exceeding basal leaves, Leaves mostly cauline, Leaves conspicuously 2-ranked, distichous, Leaves sheathing at base, Leaf sheath mostly open, or loose, Leaf sheath hairy, hispid or prickly, Leaf sheath and blade differentiated, Leaf blades lanceolate, Leaf blades ovate, Leaf blades 2-10 mm wide, Leaf blades 1-2 cm wide, Leaf blades mostly flat, Leaf blades mostly glabrous, Leaf blades more or less hairy, Leaf blades scabrous, roughened, or wrinkled, Ligule present, Ligule a fringed, ciliate, or lobed membrane, Inflorescence terminal, Inflorescence an open panicle, openly paniculate, branches spreading, Inflorescence solitary, with 1 spike, fascicle, glomerule, head, or cluster per stem or culm, Inflorescence branches more than 10 to numerous, Peduncle or rachis scabrous or pubescent, often with long hairs, Flowers bisexual, Spikelets pedicellate, Spikelets dorsally compressed or terete, Spikelet less than 3 mm wide, Spikelets with 1 fertile floret, Spikelets with 2 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 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, Glumes 3 nerved, Glumes 4-7 nerved, Lemma similar in texture to glumes, Lemma 8-15 nerved, Lemma glabrous, Lemma apex truncate, rounded, or obtuse, Lemma awnless, Lemma margins inrolled, tightly covering palea and caryopsis, Lemma straight, Palea present, well developed, Palea about equal to le mma, Stamens 3, Styles 2-fid, deeply 2-branched, Stigmas 2, Fruit - caryopsis, Caryopsis ellipsoid, longitudinally grooved, hilum long-linear.

Panicum hirticaule is a species of grass known by the common names Mexican panicgrass and roughstalked witchgrass. It is also known as the Sonoran millet, and is cultivated as a cereal crop in the American Southwest.