288 BUCKWHEAT FAMILY. 



P. t6nue. Rocky dry soil : slender, upright, with thread-like branches, 

 along which the upper flowers form a loose leafy spike ; leaves narrow linear, 

 acute ; akene shining. 



2. Flowers collected in terminal x, .//,>.< or spike-like racemes, rose-purple or flesh- 

 color, <>r rarely white or nremish. 



* Leaves small awl thn ad-liki- <ir at l< >i<//h none : the shrnths truncate, naked, ri'/id : 



manij-jomtdl nien,/e with a single flower under each bract. 



P. articulatum. Sandy shores and barrens : a slender little plant, bushy- 

 branching, 4' -12' high; flowers rose-colored, nodding; stamens 8; akene 

 triangular. 



* * Leaves ovate, short-petioled : sheaths cylindrical, fringr-d-hairy : greenish 



flowers 1-3 from each bract of the lo/i>/ mid slender sj>ii(-f*, unequally 4- 

 parted ; the 2 styles rfflexed on the lenticular akene and hooked at the ti/>. 



P. Virginianum. Thickets: 2 -4 high, nearly smooth ; leaves rough- 

 ciliate, 3'- 6' long ; flower somewhat curved ; stamens 5. 2/ 



* * * Leaves lanceolate, oblong, or ovate, chiefly pt-tioltd : sheaths cylindrical: 



flowrs several from each bract of the spike, b-jxtrtid. 



4- Sheaths mostly with an abruptly spreading foliaceous liorder (which sometimes 

 falls ojT) : tall, 3 -8 high, with dense cylindrical nod 'ding spikes of rose- 

 colored flowers, and flat akenes. 



P. orientale, PRIXCKS' FKATHER. Gardens and cultivated grounds, from 

 India : with large ovate pointed leaves, and 7 stamen-. 



P. Careyi. Swamps from Pennsylvania N. & E. : with lanceolate leaves, 

 glaudular bristly peduncles, and 5 stamens. 



-i- - Sheaths truncate, without a border. 



t-f Herbage and flowers not acrid nor punctate with pellucid glands or dots. 

 = In moist soil : leaves lanceolate : plants nearly smooth. (T) 



P. incarnatum. Tall, 3 -6 high ; leaves tapering from near the baso 

 to a narrow point (4' -12' long) ; sheaths smooth and naked ; peduncle* rou_ r h 

 with scattered sessile glands ; spikes linear, nodding ; (lowers flesh-color or pale 

 rose; the ("> stamens and ~2 st\ les included ; akene fiat with concave sides. 



P. PennsylvaniCUm. Stems l-3 high, the branches above and pe- 

 duncles bristly with stalked -lands ; sheaths naked ; spikes oblong, thick and 

 blunt, erect ; flowers rose-purple; stamens j<, a little protruding ; styles-cleft; 

 akene with flat sides. 



P. Persicaria, LADY'S THUMB. Tsat. from Kit. near dwellings, about 

 1 high: upper face of leaves with a dark blotch near the middle: sheaths 

 su;ii''wliat bristly-ciliate ; spikes oblong, dense, evert, on naked peduncles; 

 HnuiTs Lrreeuish-purplo ; stamens mostly (' ; style S-3-clcft; akene either 

 tlattish or triangular. 



= = fn miter : at( /us rooting below. 2/ 



P. amphibium. WVTKR P. ChietlyN. : steins often simple bearing a 

 tingle ovate or oblong d-nse spike or head of pretty large and slmwv ros 



flowers; lea\es nlilung, lieart-obloiiL:, lanee-o\ate or lanceolate, mostly long- 

 petioled, often floating; sbeaths not fringed : stamen.-* 5 ; style 2-elet't. 



P. hydropiperoldes. Commonest S. : stems slender, rising out of 

 shallow wat'T l-3 liigh ; leaves narronly lanceolate or lance-oblong ; sheaths 

 hairv and fringed with IOULT bristles ; spikes erect, slender ; (lowers small, pale 

 or white ; stamens 8 ; style 3-cleft ; akene sharply triangular. 



** *-< Iferlmye (smooth) pnnqently acrid: li'iins and pule sepals marked with 

 pellucid mt or glands, in which the acrid quality rrsidm: sheaths fringed 



with bristlef. 



P. acre, WATER SMAKTWKKD. Shallow water or wet soil : stems rooting 

 at the decumbent base, rising 2- 4 hiLih : leaves lanceolate or linear, taper- 

 pointed: spikes slender, emit ; flowers whitish or pale flesh-color ; stamens 8: 

 akene sharply triangular, shining. 2Z 



