14. R. macrostàchya, Torr. (Pl. 4, fig. 1–4.) Cymes decompound, or in the northern form somewhat simple and smaller, and the spikelets usually more clustered; bristles capillary, twice the length of the achene.—Borders of ponds, Mass. to N. J. and Fla.; rare.
14. CLÀDIUM, P. Browne. Twig-Rush. ([Pl. 5.])
Spikelets ovoid or oblong, of several loosely imbricated scales; the lower empty, one or two above bearing a staminate or imperfect flower; the terminal flower perfect and fertile. Perianth none. Stamens 2. Style 2–3-cleft, deciduous. Achene ovoid or globular, somewhat corky at the summit, or pointed, without any tubercle, in which it differs from Rhynchospora. (Diminutive of κλάδος, a branch, from the repeatedly branched cyme of the original species.)
1. C. mariscoìdes, Torr. Perennial; culm obscurely triangular (1–2° high); leaves narrow, channelled, scarcely rough-margined; cymes small; the spikelets clustered in heads 3–8 together on 2–4 peduncles; style 3-cleft.—Bogs, N. Scotia to Del., west to S. Minn. and Iowa. July.
15. SCLÈRIA, Berg. Nut-Rush. ([Pl. 5.])
Flowers monœcious; the fertile spikelets 1-flowered, usually intermixed with clusters of few-flowered staminate spikelets. Scales loosely imbricated, the lower empty. Stamens 1–3. Style 3-cleft. Achene globular, stony, bony, or enamel-like in texture. Bristles, etc., none. Perennials, with triangular leafy culms, mostly from creeping rootstocks; flowering in summer; all in low ground or swamps. Inflorescence, in our species, of terminal and axillary clusters, the lower clusters usually peduncled. (Name, σκληρία, hardness, from the indurated fruit.)
[*] Achene smooth.
1. S. triglomeràta, Michx. Culm (1½–3° high) and broadly linear leaves roughish; fascicles of spikelets few, the lowest peduncled, the upper somewhat in threes; achene ovate-globose or depressed, on an obscure crustaceous disk.—Mass. and Vt. to Fla., west to Minn. and Tex.—Var. grácilis, Britton. Culms slender (1–2° long); fascicles few-flowered, the lower (2–3-flowered) on very long filiform peduncles; achene not more than half as large, acutish.—N. J.
2. S. oligántha, Ell. Culms slender, 2° high, the angles somewhat winged; leaves linear (2´´ wide), smooth except the scabrous apex; lateral fascicles 1 or 2, usually on long exserted peduncles; achene ovate, on a tuberculate disk.—Va. to Fla. and Tex.
[*][*] Achene papillose or warty.