Manual of the New Zealand Flora.
5. Panicum, Linn
5. Panicum, Linn.
Annual or perennial grasses, of very various habit. Spikelets lanceolate to ovate or broadly oblong, rarely globose, acuminate or acute or obtuse, articulate on the pedicel, laxly or densely paniculate, or very shortly pedicelled along one side of slender simple or branched spikes, seldom awned, glabrous or pubescent, never with bristles or spines at the base, with a single terminal hermaphrodite flower, sometimes with a male one below it. Glumes 4; the lowermost small, sometimes minute, empty; the 2nd and 3rd unequal or subequal, membranous, awnless or rarely awned, empty or the 3rd containing a male or rudimentary flower; 4th or flowering glume shorter or as long as the 3rd, firmer and more coriaceous, hardening in fruit. Palea like the flowering glume but smaller, 2-nerved. Lodicules 2. Grain enclosed in the hardened flowering glume and palea, oblong or ellipsoid; hilum punctiform.
As characterized above, this is a heterogeneous assemblage of about 300 species, found in all warm climates, but rare or absent in temperate countries. The single New Zealand species belongs to the section Digitaria, often kept as a distinct genus, in which the spikelets are almost sessile on one side of simple digitate spikes.
1. | P. sanguinale, Linn. Sp. Plant. 57.—Annual. Culms creeping or rooting at the base, then spreading or erect, 6–18 in. long. Leaves 1–6 in. long by ⅙–⅓ in. broad, flat, flaccid, pubescent or glabrous; sheaths thin, rather loose, often pilose and bearded at the nodes; ligules truncate, membranous. Spikes few or many, usually 3–6, varying in length from 1 to 4 in., crowded at the end of the culm, strict, spreading or erect; rhachis triquetrous or flattened. margins scaberulous. Spikelets geminate, one sessile, the other pedicelled, oblong-lanceolate, acute, greenish or purplish, 1/15–1/12 in. long. Outer glume very minute, ovate, acute; 2nd small, ovate-lanceolate, 3-nerved, about ½ the length of the flowering glume; 3rd rather longer than the flowering glume, oblong, acute, 6–7-nerved, the nerves often ciliate; 4th or flowering glume oblong, firm and subcoriaceous, acute or acuminate.— Benth. Fl. Austral. vii. 469; Cheesem. in Trans. N.Z. Inst. xx. (1888) 175. Kermadec Islands: Not uncommon in shady places. North and South Islands: Abundant as a naturalised weed. The Kermadec Islands plant, which is the only one which can be considered as indigenous, is referred by Hackel to the variety microbachne (Panicum microbachne, Presl.), and is a much more delicate and slender plant than the type, which is now plentiful as a naturalised weed in cultivated ground in most parts of New Zealand, as in all warm countries. |