POLYGONACBAE 247 



Perennial. Stem 12 to 18 inches long, nearly simple, striate, smooth below, 

 hirsute near the summit, decumbent at base, radicating at the lower nodes. 

 Leaves 4 to 6 inches long, sometimes ovate-lanceolate, the upper ones subsessile, 

 the lower ones on. petioles 1 to 3 inches in length; stipules tubular, the lower ones 

 smooth, upper ones hirsute, Racemes few, dense-flowered, 2 to 3 inches long; 

 flowers bright purple; pedicels shorter than the hirsute sheathing bracts. 

 Hob. Margin of the Schuylkill: rare. Fl. Aug. Fr. Octo. 



Obs. There are 1 or 2 pretty distinct varieties of this semi-aquatic 

 species, partly, perhaps, owing to their places of growth ; being 

 found sometimes floating in pools, at others radicating on the 

 mud, along their margin. 



5. !" V i rtf ill i Jill mil, L. Leaves lance-ovate, acuminate ; 

 stipules ciliate ; raceme spike-like, virgate, slender ; flowers sub- 

 solitary and distant; calyx 4-parted; stamens 5. 



VIRGINIAN POLYGONUM. 



Perennial. Stem 2 to 3 or 4 feet high, fimple, striate-ribbed, hairy above, near 

 the nodes. Leaves 3 to 6 inches long; petioles % to % of an inch in length; 

 stipules tubular, very hairy. Raceme 12 to 18 inches long, simple, sometimes 1 

 or 2 shorter ones from the axils of the upper leaves ; flowers greenish-white, or 

 often purplish, mostly solitary, a little recurved, conspicuously articulated to short 

 pedicels which proceed from tubular bristly-ciliate bracts. 

 Hob. Rich woods; borders of thickets: frequent. Fl. July. Fr. Sept. 



** Styles mostly 3, and akene triquetrous; stamens 6 or 8. 



6. P. Hydroplper, L. Very acrid ; leaves lanceolate, pellucid-punc- 

 tate, wavy-margined ; stipules ciliate with shortish bristles ; racemes 

 filiform, flaccid and nodding ; fascicles few-flowered, rather distant ; 

 calyx glandular-dotted. 



P. punctatum. Fl. Cestr. ed. 2. p. 248. not of Ell. (/^ENGELMANN). 

 WATER-PEPPER POLYGONUM. Water-Pepper. Smart-weed. 



Annual. Stem 12 to 18 inches high, slender, more or less branched, sometimes 

 decumbent, smooth, often purplish. Leaves 2 to 4 inches long, acute at each end, 

 eubsessile; stipules tubular, somewhat inflated, hairy, fringed with bristles % to 

 % the length of the tube. Racemes 2 to 4 inches long, slender and interrupted, at 

 first nodding, finally erect; fascicles 2- to 4- flowered; flowers greenish, with white 

 edges ; pedicels proceeding from bristly-ciliate sheathing bracts. Styles sometimes 

 2. Akenes opaque and roughish-dotted. 

 Hab. Moist waste grounds: introduced? Nat. of Europe. Fl. Aug. Fr, Sept. 



Obs. I have a suspicion that this is but a naturalized weed, among 

 us. It would seem to be distinct from the P. punctatum, of ELLIOTT, 

 with which I have heretofore confounded it. Dr. ENGELMANN, 

 writing to me, in October, 1847, says Polygonum Hydropiper and 

 P. punctatum are two well-distinguished species; known from a 

 distance already by the heavy pendulous green spikes of the former, 

 and the light more distant-flowered erect whitish spikes of the lat- 

 ter ; this has, also, amongst other distinguishing characters, shining 

 smooth nuts, the other opaque rough ones, &c. Both grow here 

 [St. Louis, Missouri] common." 



7. P. hydropiperoides, MX. Not acrid; leaves linear lanoeo- 



