Polygonum. CX. POLYGONACE^. 475 



9. P. ORIENTALS. Oriental Knot-grass. Prince's Feather. 



St. erect, paniculately branched; Ivs. large, with hairy, salver-form sti- 

 pules ; sia. 7; stij. 2.—® Native of the East, naturalized in fields and roadsides, 

 throughout the U. S. A tall, showy plant, often cultivated for ornament. 

 Stem 5— 8f high. Leaves 8—12' long, J as wide, ovate, acuminate. Spikes 

 numerous, large, red, plimie-like, terminal. Aug. ^ f 



10. P. AMPHiBiUM. (P. coccinium. Mu/d.) Amphibious Knot-weed. 



St. assurgent, prostrate or decumbent at base, rooting at the lower joints • 

 Ivs. oblong-lanceolate and oblong, acute, or rounded or cordate at base, petiolate' 

 smooth, acute or acuminate at apex ; spike terminal, ovoid or oblong, dense •' 

 sta. 5 ; sty. 2-cleft. — Marshes, ponds, N. Eng. to 111. A very variable species' 

 with large leaves and a terminal, dense spike of bright red flowers. Stems 

 smooth, furrowed, short-jointed, often very long and creeping or floating and 

 rooting. Stipules large, sheathing, mostly lacerated. Leaves 5 — 7' by 1 — 2' 

 often shining. Spikes 1 — 2' long, the shorter mostly thicker. Aug The prin- 

 cipal varieties are as follows : 



a. coccineum. St. thick, suberect, 1 — 3f long; Ivs. oblong, acute, shining 

 both sides; stijntles truncate; spikes ovoid. (N. Eng. !) 



p. natans. St. very long, thick, rooting, prostrate, with erect branches ; Ivs. 

 lance-oblong, subcordate, acuminate, stip. lacerate, long ; spike long, slender. 

 (Indiana ! &c.) 



y. {P.fluitans. Ea. ?) L/os. lance-linear, tapering to each end ; ochrece long, 

 hirsute, with a lealy, spreading summit ; spike oblong. — Lancaster, N. H. 

 Richard I Wisconsin, Lapham! — I am by no means certem that these three 

 varieties are not distinct. 



11. P. ViRGINIANUM. 



St. simple, pilose above ; Ivs. broadly lanceolate, ciliate-serrulate, acumi- 

 nate, smooth, on short petioles ; rac. long, slender, few-flowered ; fis. tetrame- 

 rous, unequal, remote ; sta. 5 ; sty. 2, unequal. — % Shades, Can. to Flor., W, 

 to Miss. Stem 2 — 4f high. Leaves 3 — 6' long, ^ as wide, petioles 1 — 5" long. 

 Stipules hairy. Spike or raceme terminal, simple or with one or two branch- 

 lets, leafless, 1 — 2f long. Flowers small, white, Jl., Aug. 



§ 3. BisTORTA. Fls. in terminal^ solitary spikes. Sta. 7 — 9. Stig. 3. 



12. P. viviPARUM. Vivipcrous Bistort. 



S/.. simple ; Ivs. linear-lanceolate, revolute at the margin; spike linear, 

 solitary. — Stem erect, leafy, Jf high, bearing a single spike of white flowers 

 which are often transformed into bulblets while on the stem. — 'Z|. White Mts. N. 

 to Arc. Am. Leaves 1 — IJ' by 2 — 3", with entire, obtuse, smooth stipules. JL 



13. P. niRsuTUM. Walt. Hairy Knot-grass. 



St. and stip. very hirsute ; Ivs. lanceolate, hirsute, punctate with pellucid 

 dots ; spikes filiform ; sta. 7 ; sty. 3-parted. — ® On river banks, Ohio and South- 

 ern States. The whole plant is clothed with soft hairs. Stem 2f high. Flowers 

 white. July. 



§ 4. PoLYGONELLA. Flowcrs in paiiicidale spikcs. Stamens 8. 



14. P. ARTicuLATUM. Jointcd Polygonuvi. 



• <S/. erect ; lis. linear ; spikes panicled, filiform ; fs. solitary, pedunculated, 

 with imbricate, truncated bracts ; sta. 8 ; sly. 3. — (1) N. Y., Mich., found in dry, 

 hilly pastures. Stem slender, branching, straight, with numerous, racemed 

 spikes, and imbricate, sheathing bracts. Leaves I — 1' by 1 — 2", obtuse. 

 Flowers flesh-colored, on noddjpg, hair-like peduncles issuing from above the 

 bracts. Achenia acutely triangular. Aug. 

 § 5. Fagopyrum. Fls. in racemose panicles. Lvs. subcordate or sagittate. 



15. P. SAGITTATUM. Scratchgrass. 



St. prostrate, rough-angled; te. sagittate ; fls. capitate; sta. 8; sty. 3. — ® 

 Wet grounds, N. Eng. to Flor. and W. States. A rough, climbing species, 

 often several feet in length. Stem square, the aiagles very rough with prickles 

 pointing downwards. Leaves acute, 1 — 3' long, J as wide, on petioles \ — f 

 long, with smooth stipules. Flowers in small, terminal heads, whitish. Jn, 



