Polygonum. CX. POLYGONACE^. 475 



9. P. ORiENTALE. Oriental Knot-grass. Princess Feather. 



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

 pules ; sta. 7 ; sty. 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, plume-like, terminal. Aug. ^ f 



10. P. AMPHiBiuM. (P. coccinium. Muhl.) Amphibious Knotr-weed. 



SI. 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, otten 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. cuccineum. St. thick, suberect, 1 — 3f long; Ivs. oblong, acute, shining 

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



fi. nutans. St. very long, thick, rooting, prostrate, with erect branches ; Ivs. 

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

 (Indiana! &c.) 



y. {P.fiuitans. Ea. ?) Ijvs. lance-linear, tapering to each end ; ochrece long, 

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

 Rickard ! Wisconsin, Lapham ! — I am by no means certain that these three 

 varieties are not distinct. 



11. P. VlRGINIANUM. 



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. Viviperous 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. — % White Mts. N. 

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



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



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

 dots ; spikes filiform ; sta. 7 ; sly. 3-parted. — (I) On river banks, Ohio and South- 

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

 white. July. 



§ 4. PoLYGONELLA. Flowers in paniculate spikes. Stamens 8. 



14. P. ARTicuLATCM. Jointed Polygonum. 



S'. erect ; lis. linear ; spikes panicled, filiform; fls. solitary, pedunculated, 

 with imbricate, truncated bracts ; sta. 8 ; sty. 3. — ® 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 nodding, hair-like peduncles issuing from above the 

 bracts. Achenia acutely triangular. Aug. 



§5. Fagopyrum. Fls. i7i racemose panicles. Lvs. subcordate or sagittate. 



15. P. SAGiTTATUM. Scratchgrass. 



St. prostrate, rough-angled ;"Zz-5. sagittate; fls. capitate; sta. 8; sty. 3. — (j) 

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

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

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

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



