300 POLYGONACICvE. (BUCKWHEAT FAMILY.) 



$ 3. Avici lab i v. llowers axillary, single or 2 - 3 together: stamens 8, rarely 

 fewer: stigmas 3, nearly sessile: achenium 3-angkd: cotyledons incumbent: albu- 

 men Jtorny: skeatlis scarious, 2 -3-]>arted, lacerated: leaves small. 



10. P. aviculare, L. Stem prostrate, diffuse, short-jointed ; leaves sessile 

 [ty long), oblong-linear or lanceolate, obtuse, longer than the 3-cleft sheaths; 

 flower:; clustered, nearly sessile, greenish-white, longer than the dull achenium ; 

 stamens mostly 5. — Waste places and along roads, common. — Var. ERECTUM. 

 (P. crectum, /,.) Stem stouter, erect or ascending, leaves larger (1'- \}j' long), 

 oblong. — With the preceding. — Var. LITTOEALE. (P. niaritimum, L. P. 

 glaucum, Xutt.) Stem long (l°-2°), prostrate, rigid, short-jointed; leaves 

 small (4'-G"), 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. 



11. 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. Q) — Stem 6' - 8' high. Leaves 6" - 12" long. 



§ 4. TOY ARIA. Flowers scattered in a long and slender spike: calyx 4-]iarted : 

 stamens 5, included: styles 2, exserted, persistent : achenium lenticular: cotyledons 

 aceumbent, 



12. P. Virginianum, L. Stem erect, smooth below; the upper portion, 

 like the leaves and spikes, more or less hairy; leaves huge, 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. lj. — Flant 2° - 4° high. Leaves 3' - 5' long, 

 1 y - 2£ ; wide. Spike 6' - 1 2' long. 



(j 5. EcHIKOCAULOH. Flowers in terminal clusters: calyx 4 - 5-partul : stamens 

 6 or 8 : styles 2-3: achenium lenticular or S-angled: cotyledons aceumbent. — 

 Stems weak, branching, armed on the angles, petioles, <jv. with recurved prickUs. 



13. P. arifolium, L. Leaves hastate, acuminate, membranaceous, mi- 

 nutely dotted and hairy, long-pctioled, the lobes acute ; peduncles rather short, 

 bristly ; flowers white, somewhat spiked ; stamens G ; 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, Bhort-petioled, 

 smooth ; peduncles elongated, smooth ; flowers white, capitate ; stamens 8 ; 

 Styles 3; achenium 3-angled. — ,Wel places, Florida, and northward. June- 

 Oct. Qj— Stem l°-3° long. Leaves l r - 2' long. 



4 G. TlHIARIA. Flowers in axillary dusters or racancs: calyx greenish white, 

 5-parted, the. outer lobes heeled or winged on the bach .- stamens 8 : styles 3, very 

 short: achenium D-anghd: COtyUdons a<cumh<ut. — Annuals, with twining sUn,s 



and cordate leaves. 



l. r >. P. Convolvulus, L. Stem roughish, prostrate or twining, or when 

 small erect ; leaves long-pctioled, sagittate-cordate, acuminate, the lobes acute or 



