PoiyGonum. CX. POLYGONACE. 475 
9. P. ORIENTALE. Oriental Knot-grass. Prince’s Feather. 
St. erect, paniculately branched; lws. 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. § t 
10. P. ampHipium. (P.coccinium. Muhl.) Amphibious Knot-weed. 
St. assurgent, prostrate or decumbent at base, ruoting at the lower joints; 
lws. 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 lll. 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. coccinewm. St. thick, suberect, 1—3f long; Ws. oblong, acute, shining 
both sides; stipules truncate; spikes ovoid. (N. Eng.!) 
B. natans. St. very long, thick, rooting, prostrate, with erect branches; Js. 
lance-oblong, subcordate, acuminate, stip. lacerate, long; spike long, slender. 
(Indiana! &c.) : 
y- (P. fluitans. Ea.?) Lvs. \ance-linear, tapering to each end; ochree 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. VirGIniinum. 
St. simple, pilose above ; dvs. broadly lanceolate, ciliate-serrulate, acumi- 
nate, smooth, on short petioles; vac. 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. F'ls. in terminal, solitary spikes. Sta.7—9. Stig. 3. 
12. P. vivipinuM. Viviperous Bistort. 
St. simple; lws. linear-lanceolate, revolute at the margin; spike linear, 
solitary—Stem erect, leafy, 4f high, bearing a single spike of white flowers 
which are often transformed into bulblets while on the stem.—2| White Mts. N. 
to Arc. Am. Leaves 1—1}’ by 2—3”, with entire, obtuse, smooth stipules. Jl. 
13. P. sirsttum. Walt. Hairy Knot-grass. 
St. and stip. very hirsute ; lvs. 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. PotyconeLia. Flowers in paniculate spikes. Stamens 8. 
14. P. arTicuLATUM. Jointed Polygonum. 
St. erect; lvs. linear ; spikes panicled, filiform; fs. 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 4—1’ by 1—2”, obtuse. 
Flowers flesh-colored, on nodding, hair-like peduncles issuing from above the 
bracts. Achenia acutely triangular. Aug. 
§5. Facopyrum. F'ls. in racemose panicles, Lvs. subcordate or sagittate. 
15. P. sacirritum. Scratchgrass. 
St. prostrate, rough-angled; luvs. sagittate; fils, 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 
inting downwards. Leaves acute, 1—3/ long, } as wide, on petioles }—3/ 
ong, with smooth stipules. Flowers in small, terminal heads, whitish. Jn. 
