OCTANDRIA, TRIGYNIA. 187 
Flax-leaved Polygonum. 
About six or eight inches high. Flowers small, white or 
pale-biossom-red. In dry sandy fields of Jersey, and on the 
sandy commons near Camden ; common. In a sandy field a 
mile or two above the falls of Schuylkill, west side ; frequent. 
Annual. July. 
§ 2. Flowers spiked and terminal. 
! 3. P. flowers pentandrous, digynous, unequal ^ virginiamiifl. 
I leaves broad-oval | spike very long, virgate, 
flowers remote. 
P. rostratum, Muhl. 
P. bistorta, Walt ? 
From eighteen inches to two feet high. Flowers small-, 
white, inconspicuous. Seed rostrate. In shady woods not 
unfrequent. In the woods of Powelton, abundant. Perennial. 
June, July. 
4. P. flowers crowded, octandrous, with the style Pennsyiva- 
£-cleft; peduncles hispid; stipules glabrous ; 
leaves lanceolate, a little hairy. — Sp. PL 
Pennsylvania Knot-weed. 
Flowers large, rose-coloured. Plant from one to two feet 
high. In cultivated fields and on the borders of ditches ; com- 
mon. Annual. From midsummer till autumn. 
5. P. flowers octandrous, semi-trigynous, leaves punctatnm, 
lanceolate, smooth ; ochrese loose, smooth, dil- 
ate at the apex, spotted ; spikes filiform, weak, 
subnutant; bractes somewhat remote, alter- 
nate. — Mich. 
P. punctatum, Elliot. 
P. hydropiperoides, Pursh, not Mich. 
P. hydropiper, Mich. 
P. persicaria, W alt ? 
Water-pepper Knot-weed. 
Grows with No. 4, and No. 6. Perennial. All summer. 
6. P. flowers hexandrous, semi-digynous, spikes Persicaria. 
ovate-oblong, erect, peduncles smooth j leaves 
