ORDEU 104. POLYGON ACE J3. 283 



tic, acutish, 1' ; flowers 2 or 3 together, subsessile, reddish ; achenia striate, dull, 

 enclosed ; stamens 58. A common weed, 616'. In rich shady soils it arises to 

 &. ereftum, with larger oval leaves and pedice_ate flowers. 



2 P. teiiue MX. Slender, rigid, erect, with long simple-angular branches ; Ivs. lineai, 



erect ; eheaths bristle-fringed ; flowers solitary ; achenia shining. Dry. j If. 



3 P. mari timum L. Prostrate, diffuse, glaucous, with very short joints and swell- 



ing torn sheaths ; Ivs. fleshy, oblong, 1 6 V ; fls. sessile, at length spicate ; fruit little 

 exserted, smooth and shining. Sandy coasts, Mass, to Ga. 1 If. 



4 P. ramosissimum MX. Erect or ascending, much branched, striate ; Ivs. linear 



obloug, 12' ; flowers greenish, pedicellate ; fruit i exserted, olive-green, shining, 

 H". Sandy shores, R. I. to Mich, and Md. 2 3f. 



5 P. hirsutum Walt. Densely hirsute with spreading tawny hairs, erect; Ivs. lan- 



ceolate ; sheaths fringed ; flowers white, in 2 or 3 slender spike:*. (2) S. 2 3f. 



6 P. liydropiperoides MX. Mild Water-pepper. Stem smooth, slender, sheaths 



long, close, fringed and hispid ; Ivs. linear-lanceolate, not acrid ; spikes erect, slen- 

 der, loose at base ; calyx glandless , achenia shining. 

 /3. se.acta the leaves and stem above are more or less hispid, y. Wet. 1 3f. 



7 P. acre H. B. K. Wafer Smartweed, Glabrous, virgate, slender ; sheath loose, 



bristle-fringed; Ivs. lanceolate, acrid; spikes filiform, erect ; flowers reddish-green, 

 dotted like the leaves ; fruit shining. Wet places. S. and W. 2 5f. 



8 P. TINCTORIUM. Madder. Lvs. oval ; spikes oblong, dense, roseate. China. 1 2f. 



9 P. Hydropiper L. Water Pepper. Glabrous : sheaths brislly-ciliate ; Ivs. lanceo- 



late., very acrid, finely punctate ; spikes nodding, loose, slender, greenish ; calyx 

 punctate ; stamens mostly 6 ; achenia roughened, black. Damp. 1 2f. 



10 P. Cireyi Olney. Stem erect, 3 5f, bristly and much branched; leaves lanceo- 

 late, some hispid ; stipules tubular-truncate, ciliate ; spikes dense, purplish, nodding 

 on long hairy peduncles. Swamps, N. Eng. to Penn. (See p. 44T.) 



IIP. Persiciria L. Smart-weed. Glabrous, erect: leaves lanceolate, usually 

 marked with a brown spot ; sheaths fringed ; spikes dense, erect, oblong ; stamens 

 6 ; style 2-cleft ; achenia shining. Waste grounds : common. 1 2f. 



12 P. Pennsylvanicum L. Branches above and pedicels glandular-hispid ; leavea 

 lanceolate ; spikes erect, oblong, crowded, rose-colored, showy ; achenia lens-shaped, 

 with flat sides. Margins of waters. 2 4f. 



0. densifloruni. Smooth; racemes slender; achenia truly lens-shaped. South. 



1 3 P. incarnatum Ell. Smoothish ; leaves lanceolate ; branches and ped. glandu- 

 lar-dotted ; spikes linear, nodding, becoming long ; acheuia lens-shaped, with con- 

 cave sides. Ditches and pools, W. and S. 2 3f. 



14 P. amphifoium L. Stem prostrate and rooting beloWj ascending; leaves thick, 

 smooth, lance-oblong, variable ; spikes oblong, ovoid or dense ; stamens 5 ; style 2- 

 cleft. Pools and swamps. 3 4f. Spike V or more. 



ft. terrentre. Plant more or less hirsute ; spikes elongated. 



15 P. viviparnm L. Low, simple, erect from a creeping rhizome; leaves lance 

 linear, with rolled edges ; spike 1, linear, u White Mountains, and N. 



1 6 P. orientale L. Pj-ince's Feather. Tall, erect, branched ; leaves large, with 

 hairy salver-form sheaths ; stamens 7 ; styles 2 ; spikes large, red, nodding, showy. 

 Fields and gardens. 3 8f. 



1 7 P. Vir iiiiiiiium L. Stem simple ; leaves lance-ovate, acuminate flowers re- 

 mote, 1 from each sheath, in a slender raceme, greenish, n Shades. 3-^f. 



18 P. convolvulus L. Knot Bindweed. Prostrate or climbing, ronghish , sheatha 

 naked ; leaves hastate, pointed ; flowers in axillary fascicles or in interrupted ra- 



cemes ; fruit exserted, dull, blackish. Fields. 2 4f. 



1 9 P. clllnode MX. Climbing ; sheaths ciliate at base ; leaves deeply cordate, 

 pointed ; racemes paniculate, loose ; achenia shining. Hedges. 3 Sf. 



20 P. dumetorum L. Hedge Bindweed. Climbing high ; joints not ciliate ; leavea 



