Order 102.— -POLYGONACE^. 60T 



men. — Herbs or shrubs with very narrow, deciduous lvs., and the small 

 lis. Eolitary in each ochrea. (Polygonum, Nutt., <tc.) 



^ Flowers subscssile. Filaments all filiform. Leaves broader above, spatulato Nos. 1, 2 



§ Flowers on capillary pedicels 2" long; 3 inner lilatnents dilated ut base. Lvs. linear. Nos. 3, 4 



1 P. parvifolia Mx. Somewhat shrubby; branches Etrict, leafless above; lvs. 

 linear-ciimate, obtuse; panicle compound, spreading; rac. numerous, sessile, fili- 

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

 (he acute achenium, 2 outer refiexed. — Pine barrens, N. Car. to Ma., Ala. and Ark. 

 A delicate, much branched shrub, I to 21" high. Sts. brittle, brownish. Lvs. 1' 

 long, 1 to 3" wide- above, tortuousfy spreading. PI; - , minute, white. 



2 P. gracile Nutt. Annual, glaucous; branches filiform, paniculate; lvs. Spain- 

 lale, obtuse, 3 to 5-veined ; rac. almost capillary, bracts approximated ; pudieels 

 very short, refiexed; sep. reflexed-spreading, at length the 3 inner exceeding tfui 

 acuminate frv.it. — Dry, sandy places, Car. to Fla. andLa. Sis. strict, furrowed, 2 

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

 Pis. nodding, 1" long, longer than the peduncle, whito or flesh-colored. 



3 P. Meisneriana Shutt. Shrubby, very leafy; lvs. linear -filiform, obtuse, 

 ■nearly perennial, glaucous ; achrae subimbrieated, green with a conspicuous white, 

 membranous border ; rac. many. flowered ; achreas 1-flowered, with setaceously 

 acuminato bracts ; 2 outer sepals refiexed. — Near Macon, Ga. (Mettaucr) and Ala, 

 rare. A delicate, bushy shrub, 1 to 2fhigh. Lvs. G to 10" long, somewhat terete 

 and fle3hy. Pis. roseate or white, on jointed, solitary pedicels 2" long. 



4 P. articulatum Meisn. St. erect, with erect branches, soon nearly naked; hs. 

 linear, caducous Lorn tho top of tho tubular, truncate sheaths ; spikes panicled, 

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

 spreading. — T) 1ST. Y. to Mich., iu dry grounds. St. slender, strict, 1 to 2f high. 

 Lvs. G ' to 1' by 1", obtuse. Pis. flesh-colored, showy, 1" long, en nodding, hair- 

 Hko peduncles. Ach. not inclosed, triangular, acuminate. Aug. — A true Poly- 

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



7. POLYG'ONUM, L. Knot-grass. (Gr. tto/Lvc, many, yuvv, 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-corncred 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 ochrcate-jointcd stems and small, white, rod, or 

 greenish lis. 



§ Stems armed wi th retrorsc prickles, Leaves cordate sagittate. TlSIAltiA No.s. 13, 2fs 



§ Stems unarmed, twining. Leaves cordate-hastate. Lciiinocaulos Nos. 17, IS 



§ Stems irect or decumbent., unarmed. Leaves hardly ever cordate. (*) 



* Calyx unequally 4-cleft. Styles 2, long deflexod. Tovaei.v No. 10 



* Calyx equally 5-parted. Styles erect, (a) 



a Sheaths salver-form. Stamens 7. Stylo 2-partcd. Tall. Ambltooomu.v.No. IS 

 a Sheaths subcylindrieal. Stamens 5, 6, 8. Styles 2 or 3. (b) 



b Flowers in leafless, terminal, spike-like racemes. Pekbicaiua. (?) 



C Raceme one, dense. Stem at base or rhizome decumbent Nos. 1.1, 14 



C Racemes several. Sheaths naked, not fringed N us. 1), 12 



C Racemes several. Sheaths bristly fringe-ciliatc. (d) 



d Style 2 (or o)-def:. Achenia flat or lens-shaped. . . Nos. S— 10 



d Style 3-cleft Achenia sharply 8-cornered Nos. 5 — 7 



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



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



e Achenium included in tho calyx, S-angled Nos. 1, "2 



IP. avicnlare L. Bird's Kxot-GRASS. St. procumbent ; lvs. elliptical-lanceolate, 

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

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

 Am. Sts. slender, i to l^f long, striate, smooth, branching, with short, white, 

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

 by 3'', moro or less. Fls. reddish, small, 2 or 3 together in tho axil3 of the leaves, 

 appearing all summer. (P. littorale Meisa.) 



