Polygonum. CX. POLYGONACEiE. 475 



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



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

 pules ; sta. 7 ; sty. 2.— (J) 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, ^ as wide, ovate, acuminate. Spikes 

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



10. P. AMPHiBiUM. (P. coccinium. Mahl.) Ampkibims Knot-ivced. 



S'. 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 ; si7j. 2-clelt. — 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, oiten 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; stipules truncate; .spikes ovoid. (N. Eng. !) 



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

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

 (Indiana! &c.) 



y. {P.fiuitans. Ea. 7) Lvs. lance-linear, tapering to each end ; ochrecz long, 

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

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

 varieties are not distinct. 



11. P. ViRGINIANUM. 



S'.. simple, pilose above ; lvs. 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 — & long, ^ as wide, petioles 1—5" long! 

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

 lets, leafless, 1 — 21 long. Flowers small, white, Jl., Aug. 



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



12. P. viviPARUM. Viviperous Bistort. 



St. simple ; lvs. linear-lanceolate, revolute at the margin ; spike linear, 

 solitary.— Stem erect, leafy, ^f 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 — 4' by 2 — 3", with entire, obtuse, smooth stipules. Jl. 



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



St. and slip, very hirsute ; lvs. lanceolate, hirsute, punctate with pellucid 

 dots; sjnkes filiform; sta. 7; sty. 3-parted.— (1) On river banks, Ohio and South- 

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

 white. July. 



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



14. P. ARTiCLLATUM. ,Jointcd Polygonum. 



S . erect; lvs. linear; spikes panicled, filiform; fls. solitarv, pedunculated, 

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

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

 .spikes, and imbricate, sheathing bracts. Leaves h — 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. in racemose panicles. Lvs. subcordate or sagittate, 



15. P. SAGiTTATUM. Scratckgrass. 



St. prostrate, rough-angled ;"/rs. sagittate; /.-;. capitate; sta. 8; sty. 3.—® 

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

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



f)ointing downwards. Leaves acute, 1 — 3' long, i as wide, on petioles \ — \' 

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



