282 ORDER 104 POLYGONACEJ?. 



6. THYSANELLA, Gray. Fls. 6 1 * S . Cal. colored, 5-parted, lobes 

 all erect, the 2 outer cordate, the 3 inner smaller, pectinate-fringed. Sta. 

 8. Styles 3. Achenia 3-angled, acuminate. A smooth, erect herb, with 

 the habit of Polygonella. (Polygonum, Ell.) 



r. ttinbrlata Gr. Pine-barrens, Ga., Fla. Stem branched, 2 3f. Sheaths bristle- 

 fringed. Lvs. linear, 12'. Fls. rose-white, in crowded, panicled spikes. July Oct. 



7. POLYGONELLA, MX. Calyx colored, 5-sepalled, persistent. Sta. 

 8, included. Styles 3 or almost 0. Ach. 3-comered, naked or enclosed in 

 the 3 inner sepals enlarged and become scarious valves. Embiyo straight. 

 Herbs or delicate shrubs, with very narrow leaves and the small flow- 

 ers solitary in each ochrea. 



Fls. dicecioua. Pedicel 1". Filaments all filiform. Stig. nearly sessile.. .Nos. 1 3 

 Fls. all o. Pedicel 2". The 3 inner filaments dilated. Styles manifest... Noe. 4, 5 



1 P. p.i rvifolia MX. Shrubby, branches strict, leafless above ; Ivs. linear-cuncato , 



panicle oblong ; inner sepal* equalling the acute achenia. S. 1 2f. 



2 P. graelJe N. Annual, glaucous ; branches filiform ; leaves spatulate ; 3 inner sepalu 



exceeding the pointed achenia. Dry sands, S. 2 3f. 



3 P. Croomla Chapm. Shrubby ; branches slender ; leaves linear (2 3") ; 3 valvcf 



unequal, 2 roundish. 1 oblong, exceeding the achenia. Uplands, S. 



4 P. Itteltmerlana Shutt. Shrubby, very leafy, leaves linear, filiform, 6 10", ever- 



green, ochrea tipped with a white membrane ; 2 outer sepals reflexed. Uplands, Ga., 

 Ala., Fla. 1 2f. A delicate bnshy shrub. 



5 P. artlculata Meisii. Annual, strict, with erect branches, which are soon nearly 



naked : leaves linear, caducous from the tops of the truncate sheaths ; sepals flesh- 

 colored, expanding. Dry. N. J., and W. : rare. 



8. POLYGONUM, L. KNOT-GRASS. Calyx of 5 sepals, rarely few ei, 

 colored or greenish, similar, imbricated in bud, at length all connivent, 

 persistent. Sta. 8, rarely fewer. Sty. 2 or 3, mostly 3, short filiform. Ach. 

 3-cornered or lens-shaped, enclosed in the dry, withered calyx. Embryo 

 curved, lateral, lying in a groove at one angle of the albumen. Herbs with 

 ochreate-jointed stems and small, white, red, or greenish fls. June Sept 



J Stems armed with retrorse prickles. Lvs. cordate-sagit. ECHINOCAULOX. .Nos. 21, 22 



Stems unarmed, twining. Leaves cordate-hastate. TINIARIA Nos. 18 2C 



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



* Calyx unequally 4-cleft. Styles 2, long deflexed. TOVARIA No. 17 



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



a Sheaths salver-form. Stamens 7. Style 2-parted. Tall. AMBLTOGONUM...NO. 1(5 

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



b Flowers in leafless, terminal, spike-like racemes. PERSICAKIA.. .(c) 

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



C Raceme 1, dense. Stem at base or rhizome decumbent Nos. 14, 13 



C Racemes several. Sheaths naked, not fringed Nos. i2, 13 



c Racemes several. Sheathg bristly, fringe-ciliate.. .(<f) 



d Style 2-(or 3-)cleft. Acheuia flat or lens-shaped NOB. 9 11 



(I Style 3-cleft. Achenia sharply 3-corr ered Nos. 58 



e Achenium protruding beyond the talyx, 3-augled Nos. 3, 4 



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



I P. avlciilarc L. Bird's A'. Do&noeed. Procumbent, diffuse ; leaves lance-ellii* 



