908 OsDES 102.— POLTGONACE^ 



y. EEECTUM. Stems ascending or erect; Ivs. larger, elliptic or oval, petiolate; 

 fls. pedicellate; stam. mostly 5. — In richer or shady soils, more common 

 westward. (P. erectum L.) 



2 P. t^nue Mx. St slender, rigid, erect, with long, simple Iranches, ocuie-aTigled ; 

 los. knear-lanceolate and linear, erect, acute; sheaths (stipules) bristly-fringed at 

 top ; fls. alternate, subsolitary ; ach. included. — A small, slender plant, on rocky 

 soils, N. Bng. to the Mts. of Ga. and Wis. St. 6' to If high. Lvs. 1 to 1 J' long, 

 1 to 2" wide, 3-veined, sessile. Pis. white. Jl., Aug. 



3 P. maTitimum L. Prostrate, diffusely branched, glaucous; st. striate, with 

 very short internodes ; sheaths gibbous at base, hyaline, torn ; lvs. fleshy, oval or 

 linear-oblong, nearly veinless ; fls. sessile ; ach. sharply angled, a little exserted, 

 smooth and shining. — U Sandy shores, E. I. to S. Car. Sts. 6 to 12' long. Lvs. 

 few and small, 2 to 4" long. Pis. often crowded in leafy racemes, rose-purpla, 

 green at base, 1" long. (P. avioulare, (3. glaucum, 2d edit.) 



4 P. ramossissimum Mx. St. tall, erect or ascending, much branched, striate; 

 sheaths 6-veiued, at length torn ; lvs. lance-oblong or linear, petiolate ; fls. subsoli- 

 tary, pedicellate, greenish ; ach. included, smooth but dull. — (D Sandy shores of 

 streams and lakes, Mich, to 111. Much hke P. aviculare, but rigidly erect, 2 to 3fi 

 with larger, petiolate lvs. 2' long, and larger sepals, 1-J-" long in fiiit, green, with 

 narrow white borders. 



5 P. hirsi^tuin Walt. Hairt Knot-ghass. Hirsute, with long, spreading, tawny 

 hairs; sheaths ciliate; to. lanceolate, obtuse at base, gradually narrowed to the 

 point; spikes 2 or 3, very slender; bract equaling its 2 or 3 pedicels; stamens 7 

 to 8 ; style 3-cleft ; ach. shining. — ® Swamps, N. Car. to Fla. St. slender, root- 

 ing at base, ascending 2 to 4£ Lvs. 2 to 3' by 4, to 10", mostly smooth above, 

 sometimes dense-hairy like the stem. PLs. white. May — Aug. 



6 P. hydroplperoides Jix. Mild Watee-pepper. St. smooth; sheaths hairy, 

 bristly-ciliate, long and narrow; lvs. linear-lanceolate, tapering to each end, 

 slightly appressed-hairy (not acrid) ; spikes 2 or more, slender, loose-flowered at 

 base; cat. glandless; stam. 8; style half-3-cleft ; ach. shining. — 1J. Ditches and 

 wet ground, common. St. branched, 1 to 3f high. Lvs. narrowed into a short , 

 petiole, not acrid. Pis. rather large, white-roseate, rather close, 4 or 5 from each 

 bract. Aug., Sept. (P. mite Pers.) 



p. betaoeum. Lts. lanceolate; stip. conspicuously fringed with long bristles. 

 — In clayey soils, southward. (P. setaceum Baldw.) 



7 P. acre H. B. K. St. ascending, slender, glabrous; sheath smoothish, fringed 

 with bristles, bearing the leaf near the base ; lvs. acrid, lanceolate, acuminate, 

 filiform, interrupted at base ; bracts truncate, 1 tb 3-flowered ; ped. scarcely ex- 

 serted; stam. 8; style 3-parted; ach. 3-cornered. — Wet places, ditches, coin- 

 mon S. and W. Cal. greenish at base, flesh-colored, brown-dotted like the lvs. 

 Ach. shining. Jl. — Sept. (P. punctatum Ell. P. hydropiperoides Ph.) 



8 P. Hydropiper L. Watee-peppbb. Glabrous; sheatln bristly-ciliate; lvs. 

 lanceolate, tapering to both ends, wiinviely, peUucid-punctals {very acrid); spikes 

 loose-flowered, slender, short (2 to 5') nodding ; ped. exserted; cal. gloMdular- 

 punctate; stam. mqgtly 6; sty. 2 or 3-cle£t; ach. flattish (rarely obtusely triangu- 

 lar), dull, minutely roughened. — (E Damp waste grounds, ditches, &c., 1 to 2f high. 

 Lvs. not more than 6" wide. Pis. green and rose-colored. Ach. black. Jl. — 

 Sept. § Eur. 



9 P. Careyi Olney. Si. erect, hirsute, much brcmched; lvs. lanceolate, with, scat- 

 tered and appressed hairs; stip. scarious, tubular, truncate, hairy-ciliate ; spikes 

 axillary and terminal, on very long, nodding peduncles thickly beset with glandular 

 hairs ; stam. 6 to 8 included ; sty. 2 ; ach. orbicular-ovate, mucronate, tumid, 

 shining.— (I) Swamps, N. Eng. and N. T.? Plant 3 to 5f high. Lvs. 3 to 6' by 

 G" to 1', midveiu and margins hairy. Cal. greenish-purple, tinged with white, 

 minutely dotted. 



10 P. Persicdria L. St. erect ; hs. lanceolate, the upper surface usually ma/rked 

 with a brownish spot; stip. fringed; spikes dense, oblong, H-ect; ped. smooth; stam. 

 6 ; sty. 2, half united ; ach. shining, flattened. — d' A common fpecies about 

 buildings, fences, wet grounds, &c. St. smooth, branched, leafy, 1 to 2f high, 



