POLYGONUM. CX. POLYGONACE^E. 475 



9. P. ORIENTALS. Oriental Knot-grass. Prince's 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, as wide, ovate, acuminate. Spikes 

 numerous, large, red, plume-like, terminal. Aug. j- 



10. P. AMPHLBIUM. (P. coccinium. Muhl.} 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; 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. fluitans. Ea. ?) Lvs. lance-linear, tapering to each end ; ochrece, long, 

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

 Rickard! Wisconsin, Lapham! I. am by no means certain 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 ; roc. long, slender, few-flowered ; fls. tetrame- 

 rous, unequal, remote ; sta. 5 ; sty. 2, unequal. 1\. Shades, Can. to Flor., W. 

 to Miss. Stem 2 4f high. Leaves 36' long, as wide, petioles 1 5" long. 

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

 lets, leafless, 'l 2f 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 ; Ivs. 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 !' by 2 3", with entire, obtuse, smooth stipules. Jl. 



13. P. HIRSUTUM. 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. Flowers in paniculate spikes. Stamens 8. 



14. P. ARTICULATUM. Jointed Polygonum. 



St. erect ; Zrs. 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 \ 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. Scratchgross. 



St. prostrate, rough-angled ; Ivs. 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 angles very rough with prickles 

 pdftiting downwards. Leaves acute, 1 3' long, as wide, on petioles i f ' 

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



