Order 102.— POLYGONAOB^. 607 



men.— Herbs or shrubs witli very narrow, deciduous Ivs., and the small 

 fis. solitary in each ochrea. (Polygonum, Nutt., &c.) 



§ Flowers eubsessile. Filaments all filiform. Leaves broader above, spatulnto Nos. 1, 2 



I Flowers on capillary pedicels 2" long. 3 inner filaments dilated at base. Lvs. linear. Nos. 8, 4 



1 P. parvifolia Mx. Somewhai shrubby; branches strict, leafless above; lvs. 

 linear-ameate, obtuse; panicle compound, spreading; rac. numerous, sessUe, fili- 

 form, short, with imbricated bracts ; fla subsessile ; inner sep. oval, soon equaling 

 the acute achenium, 2 outer reflexed. — Pine barrens, N. Car. to Fla., Ala. and Ark. 

 A delicate, much branched shrub, 1 to 2f high. Sts. brittle, brownish. Lvs. 1' 

 long, 1 to 3" wido above, tortuously spreading. Ms. minute, white. 



2 P. grdcile Nutt. Annual, glaucous; branches filiform, paniculate; lvs. spaiu- 

 late, obtuse, 3 to 5-veined; rac. almost oapillarj, bracts approximated; pedicels 

 very short, reflexed ; sep. reflexed-spreading, at length the 3 inner exceediTig tJie 

 acuminate fruit. — Dry, sandy places, Car. to Fla. and La. Sts. strict, furrowed, 2 

 to 3f high. Branching issuing from between the joints. Lvs. few, 1' to 18" long. 

 Fls. nodding, 1" long, longer than the peduncle, white or flesh-colored. 



3 P. Meisneii^na Shutt. Shrubby, very leafy; lvs. linear-filiform, obtuse, 

 nearly perennial, glaucous ; achrese subimbrieated, green with a conspicuous white, 

 membranous border ; rac. many-flowered ; aohreic l-flowered, with setaoeously 

 acuminate bracts ; 2 outer sepals reflexed. — Near Macon, Ga. (Mettauer) and Ala., 

 rare. A delicate, bushy shrub, 1 to 2f high. Lvs. 6 to 10" long, somewhat terete 

 and fleshy. Fls. roseate or white, on jointed, solitary pedicels 2" long. 



4 P. articulatum Meisn. Si. erect, with erect branches, soon nearly nalced; lvs. 

 linear, caducous from the top of the tubular, truncate sheaths ; spikes panicled, 

 filiform ; fls. solitary, pedunculated, with imbricated, truncated bracts ; sep. erect- 

 spreading. — (D N. Y. to Mich., in dry grounds. St. slender, strict, 1 to 2f high. 

 Lvs. 6" to 1' by 1", obtuse. Fls. flesh-colored, showy, 1" long, on nodding, hair- 

 like peduncles. Aoh. not inclosed, triangular, acuminate. Aug. — A true Poly- 

 gonella in habit and character, as the genus is defined by Meisner. 



7. POLYG'ONUM, L. Knot-grass. (Gr. -rroXvi;, many, yovv, knee ; 

 «'. «., plant with many joints.) Calyx of 5 sepals, rarely fewer, colored or 

 greenish, similar, imbricated in bud, at length all connivent, persistent ; 

 stamens 8, rarely fewer; styles 2 or 3, mostly 3, short filiform ; achenia 

 3-cornered or lens-shaped, inclosed in the dry, withered calyx ; embryo 

 curved, lateral, lying in a groove at one angle of the albumen. — A vast 

 genus of herbs with ochreate-jointed stems and small, white, red, or 

 greenish fls. 



I stems armed witb retrorse prickles, Leaves cordate sagittate. Tiniaria Nos. li>, 20 



I Stems unarmed, twining. Leaves cordate-hastate. Eohinocauloit. Nos. 17, 18 



I Sterna erect or decumbent, unarmed. Leaves hardly ever cordate. (*) 



* Calyx unequally 4-cleft. Styles 2, long deflexed. Tovaeia No. Ifi 



• Calyx equally 5-parted. Styles erect (a) 



a Sheaths salver-form. Stamens 7. Style 2-parted. Tall. AMnLVOGOsirsi.No. 15 

 a Sheaths subcylindrical. Stamens 5, 6, 8. Styles 2 or 8. "-(b) 



b Flowers in leafless, terminal, spike-liko racemes. Peksicabia. (c) 



C Eacome one, dense. Stem at base or rhizome decumbent Nos. 13, 14 



C Racemes several. Sheaths naked, not fringed Noa. 11, 13 



C Eacemes several. Sheaths bristly fringe-ciliate. (d) 



d Style 2 (or 8)-cleft. Achenia fiat or lens-shaped Nos. S— 10 



d Stylo 8-deft Achenia sharply 8-cornered Kos. 5—? 



d Flowers axillary or seldom forming a leafy raceme, (e) 



e Achenium protruding beyond the calyx, 8-anglod Nos. 3, 4 



e Achenium included in the calyx, 8-angled Nos. 1, 2 



1 P. aviOTilare L. Bmn's Knot-grass. St. proeumhent ; lvs. elliptical-lanceolate, 

 rough-edged, acutish at each end; fls. subsessile; ach. striate, dull, inclosed; stam. 

 6 to 8.-—^ A common weed in fields, highways and door-yards, U. S. and Brit. 

 Am. Sts. slender, i to l\{ long, stiiate, smooth, branching, with short, white, 

 torn, remotely veined stipules at the joints. Lvs. smooth, except the edges, 1' 

 by 3", more or less. Fls. reddish, small, 2 or 3 together in the axils of the leaves, 

 appearing all summer. (P. littorale Meisn.) 



