Order 102.— POLYGONAOE^E. 609 



often colored. Lvs. 2 to 4' long, a fourth as wide, entire, Bhort-stalked, acumi- 

 nate. Fls. rose-colored, in many spikes, 1 to 2' long, 6 or 6" thick. Jn. — 

 Aug. § Eur. 



11 P. Pennsylvanicum L. (Fig. 103, 607.) St. smooth, tumid at the joints; 

 lvs. lanceolate, petiolate ; stip. glabrous, not ciliate ; spikes oblong, crowded ; ped. 

 and often (he branches above glandular-hispid; stam. 8 ; sty. 2-cleft; ach. lenticular, 

 with flat sides. — CD Margins of ponds and ditches, common. St. geniculate, 

 branched above, 2 to 4f high. Lvs. 3 to 5' long, i as wide, slightly scabrous with, 

 appres.sed hairs. Spikes short and dense, large, and somewhat nodding. Fls. 

 large, rose-colored, pedicellate. Jl. 



12 P. incarnatum Ell. St. geniculate smooth below; sheaths smoothish ; lvs. 

 lanceolate, smooth except the roughish midvein and margins, or minutely pu- 

 bescent above ; branches and peduncles glandular-doited ; spikes linear, nodding, at 

 length elongated ; cal. minutely glandular ; stam. 6 ; sty. 2-clefc ; ach. lenticular 

 with concave sides. — CD In ditches and pools, "W. and S. States. Sts. 2 to 3f high. 

 Lvs. 5 to 9' by 1 to 3'. Fls. flesh-color or white, in spikes 1 to 3' long. JL— 

 Sept. (P. lapathifolium, 2d Edit.) 



13 P. amphibium L. St. assurgent, prostrate or iecumbent at base, rooting at tha 

 lower joints ; lvs. oblong -lanceolate and oblong, acute, or rounded or cordate at 

 base, petiolate, smooth, acute or acuminate at apex ; spike terminal, ovoid or ob- 

 long, dense ; sta. 5 , sty. 2-cleft. — Marshes, ponds, Can. and U. S., more common 

 North. A very variable species, with large leaves and a terminal, dense spike of 

 bright red flowers. Stip. large. Lvs. 5 to 7' by 1 to 2', otten shining. Spikes 1 

 to 2' long, the shorter mostly thicker. (Aug. P. coccinum Muhl.) 



/?. AQUATicuii. Floating, smooth ; lvs. ovate-lanceolate or oblong-ovato, shin- 

 ing, thick; spikes more usually short and thick. (P. fluitans Eaton.) 



y. terrestre. Ascending or erect, more or less hirsute ; lvs. lance-oblong, 

 acute or acuminate; sheath hirsute; spike3 moro commonly elongated. — 

 Varies into tho other. (Mr. S. II. "Wright.) 



14 P. viviparum L. Alpine Biston. St. low, erect from a creeping rhizome, 

 simple; lvs. linear-lanceolate, revolute at tho margin; spike linear, solitary. — 2£ 

 White Mts., N. II. to Arc. Am. A dwarf alpine species 6' high, bearing a ainglo 

 spike of white flowers which aro often transformed into bulblets while on tho 

 stem. Lvs. 1 to 1^-' by 2 to 3'', with entire, obtuse, smooth stipules. Jl. 



15 P. orientale L. Prince's Feather. St. erect, paniculately branched ; lvs. 

 large, with hairy, salver-form stipules ; sta. 7 ; sty. 2. — CD Native of the East, 

 naturalized in fields and roadsides, throughout tho U. S. A tall, showy plant, 

 often cultivated for ornament. Stem 5 — 8f long, \ as wide, ovate, acuminate. 

 Spikes numerous, large, red, plume-like, terminal. Aug. \ § Eur. 



26 P. Virginianum L. St. simple, minutely appressed-hairy above ; lvs. ovato 

 and lanceolate, acuminate, short-petiolate ; sheath bristly ; rac. wand-like, termi- 

 nal ; fls. remote, solitary in each sheath ; cal. 4-parted ; stam. 5, included ; sty. 2, 

 bent downwards, hooked at apex, as long as the shining, tumiddenticular ach; - 

 nium. — U Shades, Can. and U. S. St. 3 to 4f high, the raceme half its length. 

 Lvs. large, 3 to 6' long, half as wide. Fls. greenish- white. Jl., Aug. 



17 P. convolvulus L. Knot-Bindweed. St. prostrate or climbing, twining, 

 roughish; sheaOis naked; lvs. hastata, acuminate; fls. in axiilary fasicl-es or in- 

 terrupted racemes ; caL obtusely keeled ; ach. purplish-black, dull, exserted. — CD 

 Fields and waste grounds, Can. to Car. Sts. angular, 2 to 3f long. Lvs. 1 to 2' 

 by 7 to 15'', petioles half as long. CaL whitish, twico longer than the pedicels. 

 JL, Aug. § Eur. 



18 P. cilinode Mx. Minutely pubescent, twining; sheaths girt at base with a 

 ciliate hairy ring ; lvs. deeply cordate, ovate, acuminate, lobes scarcely hastate ; 

 rac. paniculate, loose-flowered, axillary and terminal ; ach. shining. — Fields and 

 hedges, Can. to "Wis. and Ga. St. slender, often reddish-purple, 3 to G to 8f long. 

 Lvs. 1' to 18" by 9 to 15", petioles about half as long. Panicles simple, 5' long 

 or less. Cal. wingless, scarcely keeled, not quito covering tho brown achenium. 

 JL— Sept. 



19 P. dumitonxm L. Hedge Bindweed. St. smooth, twining and climbing; 



39 



