Order 102.— POLYGONAOEvB. 609 



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

 nate. Fis. rose-colored, in many spikes, 1 to 2' long, 5 or 6" thick. Jn. — 

 Aug. § Eur. 



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

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

 and ofien ifie branches above glandular-hispid ; stam. 8 ; sty. 2-cleft; ach. Imticuiar, 

 wiVi flat aides.— <S) Margins of ponds and ditches, common. St. geniculate 

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

 appressed hairs. Spikes short and dense, large, and somewhat nodding. Fls. 

 large, rose-eolored, pedicellate. Jl. 



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

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

 bescent above ; brandies and peduncles glandula/r-doUed ; spikes linear, nodding, at 

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

 viitii concave sides. — (D In ditches and pools, "W. and S. States. Sts. 2 to 3f high. 

 Lvs. 5 to 9' by 1 to 8'. Pis. flesh-color or white, in spikes 1 to 3' long. Jl. — 

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



13 P. amphibium L. St. assurgeni, prostrate or iecumbent at base, rooting at the 

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

 base, petiolato, 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 T' by 1 to 2', often shining. Spikes 1 

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



fi. AQuiiicuM. Floating, smooth; lvs. ovate-lanceolate or oblong-ovate, shin- 

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



y. TERR^STKB. Ascending or erect, more or less hirsute ; lvs. lance-oblong, 

 acute or acuminate ; sheath hirsute ; spikes more commonly elongated. — 

 Varies into the other. (Mr. S. 11. Wright.) 



14 P. vivfparam L. Alpine Biston. St. lov), erect from a creeping rhizome, 

 simple; lvs. linear-lanceolate, revolute at the margin; spike linear, solitary. — If 

 "White Mta., N. IL to Arc. Am. A dwarf alpine species 6' high, bearing a single 

 spike of white flowers which are often transformed into bulblets while on the 

 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 ; \\s. 

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

 naturalized in fields and roadsides, throughout the 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, f § Eur. 



16 P. Virgini^um L. St. simple, minutely appressed-hairy above ; lvs. ovate 

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

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

 bent downwards, hooked at apex, as long as the shining, tumid-lenticular ache- 

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

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



17 P. oonv61viilua L. Knot-Bisdweed. St. prostrate or climbing, twining, 

 ronghish; sheaSts naked; lvs. hastats, acuminate; fls. in axillary fasides or in- 

 terrupted racemes ; cal. obtusely keeled ; ach. purplish-black, dull, exserted. — (J 

 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, twice longer than the pedicels. 

 Jl., Aug. § Eur. 



18 P. cilln6de Mx. Minuteiy pubescent, twining; sheaChs girt at base with u 

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

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

 hedges, Can. to Wis. and Ga. St slender, often reddish-purple, 3 to 6 to 8f long. 

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

 or less. Cal. wingless, sayoely keded, not quite covering the brown achenium. 

 Jl.— Stpt 



19 P. dunutdrum I* Hedgs Bindwbed. St. smooth, twining and climbing ; 



39 



