Manual of the New Zealand Flora.

1. Imperata, Cyr

1. Imperata, Cyr.

Tall erect perennial grasses. Leaves long. Panicles long, terminal, densely spiciform or narrow - thyrsiforrn, silky-silvery. Spikelets all similar, numerous, densely clothed with long silky hairs, usually arranged in pairs on the continuous branches of the panicle, one sessile or almost so, the other distinctly stalked, all 1-flowered. Empty glumes 3, subequal, narrow, membranous, awnless, 3–9-nerved, the 2 outer clothed with long hairs. Flowering glume usually much smaller, hyaline. Palea small, broad, hyaline, nerveless. Lodicules wanting. Stamens 1 or 2. Stigma long, exserted from the tip of the spikelet. Grain oblong, with an embryo half its length or more.

A genus of about 6 species, found in the tropical or warm temperate regions of both hemispheres. One of the New Zealand species is very widely diffused, the other is endemic in the Kermadec Islands.

Panicle densely spiciform, cylindric, obtuse, shining. Stamens 2 1. I. arundinacea.
Panicle not so dense, narrow-lanceolate, acuminate, not shining. Stamen 1 2. I. Cheesemanii.

1. I. arundinacea, Cyr. Pl. Rar. Ic. ii. 26, t. 11; var. Kœnigii, Benth. Fl. Hongk. 419.—Culms 1–3 ft. high, slender, erect, glabrous, 3–4-noded. Leaves erect, narrow, often exceeding the culms; sheaths rather loose, with a dense erect tuft of hairs at the nodes; ligules short, membranous, truncate; laminæ linear from a very narrow base, acuminate, rather rigid, flat or convolute; margins scabrid; midrib stout. Panicle densely spiciform, 3–6 in. long, cylindric, obtuse, silvery-white and shining from the long and silky hairs which conceal the glumes; branchlets very numerous, appressed; pedicels capillary or setaceous, clavate at the apex. Spikelets about ⅙ in. long, completely enveloped by fine silky hairs ⅓ in. long. Empty glumes ovate - lanceolate, obtuse or subacute, hyaline, 5–7-nerved or the uppermost nerveless. Flowering glume ⅓–½ as long as the upper empty glume, ovate, acute, glabrous, hyaline, nerveless. Palea about ½ as long as the glume, quadrate, truncate, nerveless. Stamens 2. Stigmas long, purple.— Hack in D.C. Monog. Phan. vi. 94; Stapf. Fl. Capen. vii. 321. North Island: Auckland—Near Kaitaia, R. H. Matthews! Perhaps introduced only, but it is one of those species which might be expected to be indigenous in the extreme north of the colony, and I have consequently given it the benefit of the doubt. The species, in some of its forms, is found in all warm countries; var. Kœnigii is common throughout Africa, and in Australia and Tasmania, stretching northwards to India, China, and Japan.
2. I. Cheesemanii, Hack. in Trans. N.Z. Inst. xxxv. (1903) 378.—Perennial, innovation - shoots extravaginal. Culms 1–3 ft. high, simple, stout, erect, glabrous, 3-noded. Leaves numerous, rather shorter than the culms; sheaths loose, bearded at the mouth but otherwise glabrous, the uppermost sheathing the base of the panicle, the lowest scale-like; ligules short, truncate, membranous; laminæ linear from a narrow base, acute or acuminate, ½–¾ in. broad, flat, nerved, glabrous; margins scabrid above. Panicle narrow-lanceolate, gradually narrowed upwards into an acute point, 5–10 in. long, ¾–1¼ in. broad, dense but not so much so as in I. arundinacea, greyish-white with long soft hairs that conceal the glumes, not shining; branches numerous, erecto-patent, flexuose, simple or with short branchlets in the lower half, pedicels clavate above. Spikelets about ⅛ in. long, enveloped by long soft hairs ¼–⅓ in. long. Outer glume as long as the spikelet, lanceolate, subacute, membranous, obscurely 5-nerved, laxly pilose along the back, ciliolate at the apex; the 2nd similar but 3-nerved; 3rd ⅓ shorter, broadly ovate, obtuse, hyaline, nerveless. Flowering glume ⅓ shorter than the outer empty glumes, ovate, acuminate, tridentate, hyaline, nerveless. Palea broad, truncate, fimbriate - ciliate. Stamen 1. Stigmas long, purple.—I. arundinacea, Cheesem. in Trans. N.Z. Inst. xx. (1888) 175 (not of Cyr.). Kermadec Islands: Cliffs on the north side of Sunday Island, a bundant. T. F. C., Miss Shakespear! Closely allied to I. exaltata, Brong., but a much smaller plant, with a smaller and less branched panicle, larger and broader spikelets on more clavate pedicels, and with the outer glume 5-nerved.