OCTANDRIA TRIGYNIA 249 



Root annual 1 (perennial, Ell. Torr.). Stem 12 to 18 inches high, slender, more 

 cr less branched, sometimes decumbent, smooth, often purple. Leaves 2 to 4 in- 

 ches long, and 1 third to 3 fourths of an inch wide, tapering to a slender apex, 

 acute at each end, subsessile, often hairy on the midrib and upper surface, and 

 scabrous-ciliate on the margin, marked with numerous small pellucid punctures. 

 Stipules tubular, hairy, truncate, fringed with bristles from 1 third to 2 thirds the 

 length of the tube. Spikes 2 to 4 inches long, very slender and weak, loose-flow- 

 ered, at first nodding. Floicers articulated to pedicels about as long as the peri- 

 anth, in fascicles of 2 to 4 proceeding from each truncate bristly-ciliate sheath, the 

 tower ones remote. Perianth green, covered with brownish glandular dots, the 

 margins of the segments white, often tinged with purple. Stamens often 7. Ovary 

 lenticular with 2 styles, or triquetrous with 3 styles ; styles reflcxed or recurved 

 near the middle, united at base, scarcely half as long as the ovary, rather persis- 

 tent ; stigmas capitate. Seed compressed, ovate and lenticular, or ovoid-trique- 

 trous, in either case with a short acumination, purplish black when mature, rough- 

 ish punctate under a lens. 



JIab. Moist waste grounds; margins of pools & ditches: frequent. Fl. Aug. Fr. Sept. 



Obs. The seeds of this species are generally compressed, with 2 styles ; but of- 

 ten on the same plant they are triquetrous, and then have 3 styles. It is a very 

 acrid plant, and sometimes causes obstinate ulcerative inflammation, when applied 

 tj the skin. 



6. P. mite, Pers. Leaves linear-lanceolate, narrow ; spikes terminal 

 and subterminal, slender ; fascicles of flowers rather crowded ; perianth 

 not glandular-punctate; styles 3. Beck, Bot. p. 301. 



P. hydropiperoides. Mx. Am I. p. 239. Bigel? Bost. p. 156. Not 

 of Pursh. and JSfutt, 



P« barbatum? Muhl Catal. p. 40. Bart. Phil. 1. p. 188. Not of 

 JVilld. and Pers. 



Mild Polygonum. 



Root perennial. Stem 1 to 2 feet long, erect, or often decumbent, and radicating 

 at the lower joints, terete, smooth ish, a little branched towards the summit. Leaves 

 2 to 4 inches long, and 1 fourth to 3 fourths of an inch wide, sessile, roughish-punc- 

 tate beneath, punctures not pellucid, the midrib nerves and margins scabrous 

 with short appressed hairs. Stipules tubular, hirsute, truncate, fringed with 

 bristles nearly as long as the tube. Spikes few (usually 2 or 3), chiefly terminal, 

 1 to 2 inches long. Floicers on short pedicels, in fascicles of 2 or 3, from green or 

 often purple truncate bristly-ciliate sheaths. Perianth mostly purple, without 

 glandular dots, the margins of the segments pale red, or nearly white. Styles 

 mostly 3, rarely 2. Seed triquetrous, purplish black, smooth and shining. 



Hob. Wet places; margins of rivulets: frequent. Fl. Aug. Fr. Sept.— October. 



Obs. This is sometimes found growing in the water, and partly submersed ; in 

 which cases the stem is often decumbent, and rooting at the joints. 



7. P. Persicaria, L. Leaves lanceolate, with hairy ciliate stipules ; 

 spikes terminal and axillary, ovoid-oblong, dense-flowered, erect, on 

 smooth peduncles ; flowers hexandrous ; styles 2. Beck, Bot. p. 302. 



Vulgo — Lady's Thumb. Spotted Knot-weed. 



(Jaflice — Persicaire. Germanice — Flohkraut. Hisp. — Persicaria. 



Root annual. Stem 1 to 2 feet high, erect, branching, smooth, often purplish. 

 l^avc* 2 to 4 inches long, and half an inch to an inch wide, tapering at base to 



