POLYGONACE.E. (BUCKWHEAT FAMILY.) 411 



flowers greeuish ; stameus 6 ; st)le 2-3-partecl ; acheuiuia flat or triaugular. 

 — Roadsides in the upper districts. — Stem l°-2° high. 



9. P. hydropiperoides, Michx. Stem sleuder, smooth, ascending 

 from a floating or creepmg base ; leaves linear or lanceolate, scabrous ; sheaths 

 hispid, long-f ringed ; spikes 2-3, linear, rather close-flowered; calyx pale 

 rose color, glandless ; stamens 8 ; style 3-cleft ; achenium 3-augled. — Ditches 

 and muddy banks. July - Sept. ^ — Stem 2° -3° long. Leaves 2' -4' long, 

 not acrid. Spikes l'-2'' long. 



10. P. setaceum, Baldw. Stem erect, sparingly branched, smooth be- 

 low, the upper portion, like the peduncles and lanceolate glantUess leaves, 

 rough with appressed liairs ; stipules appressed, hirsute, copiously fringed 

 witii long bristles ; spikes filiform, by pairs, loose-flowered ; flowers white, 

 glandless; stamens 8; style 3-cleft; achenium 3-angled. — Low ground, 

 Georgia and Florida. July -Sept. 2/ — Stem 2*^-3° higli. Leaves 3' -5' 

 long. Spikes r-2' long. 



11. P. hirsutum, Walt. Stem erect, densely hirsute with spreading 

 fulvous hairs ; leaves lanceolate, nearly sessile, rounded at the base, hirsute, 

 particularly on the veins and margins ; sheaths hirsute, copiously fringed ; 

 spikes 2-3, linear, erect, rather close-flowered; peduncles smooth above; 

 bracts naked; flowers white, glandless; stamens 8; achenium 3-angled. — 

 Pine barren ponds, Florida to North Carolina. July- Sept. 11 — Stem 

 2°-3°high. Leaves 2' - 3' loDg. Spikes 1' long. 



§3. AvicULAKiA. — Floivers axillary, single or 2-3 together: stamens 8, 

 rarely fewer • stigmas 5, nearly sessile : achenium 3-angled: cotyledons in- 

 cumbent: albumen horny: sheaths scarious, 2 -S-parted, lacerated: leaves 

 small, 



12. P. aviculare, L. Stem prostrate, diffuse, short-jointed ; leaves ses- 

 sile {V 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. (F. erectum, L.) Stem stouter, erect or ascending, leaves 

 larger (I'-H' long), oblong. — With the preceding. — Var. littorale. 

 (P. maritimum, L.) Stem l°-2° long, prostrate, rigid, short-jointed ; leaves 

 small (4"- 6"), oblong-linear, glaucous ; the uppermost imbricated and scarcely 

 longer tlian the conspicuous silvery sheaths ; calyx reddish white, shorter 

 than the smooth achenium. — Seacoast sands, Georgia, and uortliward. 



13. P. tenue, Michx. Smooth ; stem erect, branched, sharply angled, 

 slender; leaves .scattered, linear, acute ; sheaths sm.nll, fringed; flowers mostly 

 solitary, greenish white ; acheninm smooth and shining. — Dry rocks in the 

 upper districts. July - Sept. ® — Stem 6' - 8' higli. Leaves 6" - 12" long. 

 § 4. ToYAmx.—Floioers scattered in a long and slender spike : calyx 4-parted : 



stamens 5, included: styles 2, exserted, persistent: acJienium lenticular: 

 cotyledons acnniihent. 



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

 like the leaves and spikes, more or less hairy; leaves large, ovate or ovate- 

 lanceolate, acute at each end ; sheaths cylindrical, hairy, fringed ; flowers 



