ORDER 102. POLYGONACE^E. 807 



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

 Us. solitary in each ochrea. (Polygonum, Nutt., <fec.) 



Flowers subsessile. Filaments all filiform. Leaves broader above, spatulate ........ Nos. 1, 2 



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



1 P. parvifolia MX. Somewhat shrubby; branches strict, leafless above; Ivs. 

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

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

 the acute achcnium, 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" wide above, tortuously spreading. Fls. minute, white. 



2 P, gracile Nutt Annual, glaucous; branches filiform, paniculate; Ivs. spatu- 

 late, obtuse, 3 to 5-veined; lac. almost capillary, bracts approximated; pedicels 

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

 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. Meisneriana Shutt. Shrubby, very leafy; Ivs. linear-filiform, obtuse, 

 nearly perennial, glaucous ; achrea? subimbricated, green with a conspicuous white, 

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

 acuminate bracts ; 2 outer sepals reflexed. Xear 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. St. erect, with erect branches, soon nearly naked; Ivs. 

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

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

 spreading. T 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. Ach. 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. rro/lvf, many, yovt', knee ; 

 i. e., 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 ; embiyo 

 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. 



Stems armed with retrorse prickles. Leaves cordate sagittate. TINIARIA ......... Nos. 19, 20 



| Stems unarmed, twining. Leaves cordate-hastate. ECHINOCAULON ............... Nos. 17, IS 



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



* Calyx unequally 4-cleft. Styles 2, long deflexed. TOVAEIA ..................... No. 1 



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



a Sheaths salver-form. Stamens T. Style 2-parted. Tall. AMBLYOGOMUM . No. 15 



a Sheathj^subcylindrical. Stamens 5, 6, 8. Styles 2 or 3. (b) 



_.__. / PEKSICARIA. (c) 



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



b Flowers in leafless, terminal, spike-like racemes. PERSICARIA. 



C Racemes several. Sheaths naked, not fringed Nos. 11,12 



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



d Style 2 (or 8)-cleft. Achenia flat or lens-shapod Nos. 810 



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



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



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



e Achenium included in the calyx, 3-angled. . T Nos. 1. ii 



1 P. aviculare L. BIRD'S KXOT-GRASS. St. procumbent ; Ivs. 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^f long, striate, 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.) 



