390 POLYGONACEH. (BUCKWHEAT FAMILY.) 
$ 3. Avicutarta. Flowers axillary, single or 2 — 3 together: stamens 8, rarely 
fewer: stigmas 3, nearly sessile: achenium 3-angled : cotyledons incumbent: albu- 
men horny: sheaths scarious, 2 — 3-parted, lacerated : leaves small. 
10. P. aviculare, L. Stem prostrate, diffuse, short-jointed ; leaves sessile 
(3 long), oblong-linear or lanceolate, obtuse, longer than the 3-cleft sheaths; 
flowers clustered, nearly sessile, greenish-white, longer than the dull achenium; 
stamens mostly 5. — Waste places and along roads, common. — Var. ERECTUM. 
(P. erectum, Z.) Stem stouter, erect or ascending, leaves larger (1' - 1}! long), 
oblong. — With the preceding. — Var. LITTORALE. (P. maritimum, Z. P. 
glaucum, Nut.) Stem long (19-29), prostrate, rigid, short-jointed ; leaves 
small (4” - 6”), oblong-linear, glaucous; the uppermost imbricated and scarcely 
longer than the more conspicuous silvery sheaths ; calyx reddish-white, shorter 
than the smooth achenium. — Sea-coast sands, Georgia, and northward. 
1. P. tenue, Michx. Smooth; stem erect, branched, sharply angled, 
slender; leaves scattered, linear, acute; sheaths small, fringed ; flowers mostly 
solitary, greenish-white; achenium smooth and shining. — Dry rocks in the 
upper districts. July- Sept. @—Stem 6'-8' high. Leaves 6/-12"long. | 
$ 4. Tovarta. Flowers scattered in a long and slender spike: calyx 4-parted : 
stamens 5, included : styles 2, exserted, persistent: achenium lenticular : cotyledons 
accumbent. 
12. P. Virginianum, L. Stem erect, smooth below; the upper portion, 
like the leaves and spikes, more or less hairy; leaves large, ovate or ovate-lance- 
olate, acute at each end ; sheaths cylindrical, hairy, fringed ; flowers greenish, 
curved; styles at length hooked at the apex.—Dry rich soil, Florida, and 
northward. Aug. and Sept. 1, — Plant 2°-4° high. Leaves 3'-5' long, 
1}/- 2}! wide. Spike 6/- 12! long. 
$5. ECHINOCAULON. Flowers in terminal clusters: calyx 4 — 5-parted : stamens 
6 or 8: styles 2-3: achenium lenticular or 3-angled: cotyledons accumbent.— 
- Stems weak, branching, armed on the angles, petioles, yc. with recurved prickles. 
13. P. arifolium, L. Leaves hastate, acuminate, membranaceous, mi- 
nutely dotted and hairy, long-petioled, the lobes acute ; peduncles rather short, 
. bristly; flowers white, somewhat spiked ; stamens 6; styles 2; achenium len- 
. ticular. — Rice fields and wet places, South Carolina, and northward. June- 
Oct. ()— Stems 2°-3° long. Leaves 3'-4'long. Calyx often 4-parted. — 
14, P. sagittatum, L. Leaves small, sagittate, acute, short-petioled, 
smooth; peduncles elongated, smooth; flowers white, capitate; stamens 8; 
styles 3; achenium 3-angled.— Wet places, Florida, and northward. . June- 
Oct... @— Stem 1°-3° long. Leaves 1'- 2 long. as 
e a A Flowers in axillary clusters or racemes: calyx greenish white, 
parted, the outer lobes keeled or winged on the back: stamens 8: styles 3, VOY — 
. p. ‘ lvuh 
