POLYGONACE^. 



303 



Old fields and road sides. July, Aug. Q.—Stem 4—5 feet high, loosely 

 branched above, hairy. Flowers large, crimson, in numerous pendulous spikes. 

 Naturalized throughout the whole U. States. Prince's Feather. 



**** Flowers in panicled spikes. Perianth b-sepalled. 



13. P. articulatum Linn. : stem erect ; leaves linear, obtuse ; stipules 

 short, truncate ; spikes paniculate, filiform, erect ; pedicels solitary, articu- 

 late near the base ; flowers perfect, octandrous, trigynous, nodding. 



Sandy plains. Mass. N. Y. and N. J. W. to Michigan. Sept. Q.—Stem 

 12 inches high, branched above, smooth. Leaves very small, linear. Flowers 

 reddish-white, in spikes which are jointed by a succession of imbricate sheath- 

 ing bracts. Jointweed. 



***** Flowers in racemose panicles. Leaves subcordate or sagittate. 



14. P. sagittatum Linn. -• stem prostrate, square, the angles armed with 

 reversed prickles ; leaves sagittate, acute, nearly sessile ; flowers in small 

 peduncled heads, mostly octandrous. 



Wet grounds. N. Y. to Flor. July, Aug. 0. — Stem 2 — 4 feet long, slender, 

 procumbent or supported by other plants. Flowers white, axillary and terminal, 

 in small compact heads which are supported <tk long peduncles. 



Arrow-leaved Knotweed. 



15. P. arifolium Linn. : stem prostrate, sulcate-angled, the angles wit.'i 

 reversed prickles ; leaves on long petioles, hastate, acuminate ; flowers sub- 

 racemose, distinct, hexandrous ; styles 2. 



Wet grounds. Can. to Car. Aug., Sept. (1). — Stem 3 — 6 feet long, flexu- 

 ous, prostrate or climbing. Flowers pale-red, in loose slender racemose clusters. 



Halbert-leaved Knotweed. 



16. P. Convolvulus Linn. : stem climbing or prostrate, somewhat rough ; 

 leaves oblong, hastate-cordate, acuminate; flowers in loose axillary ra- 

 cemes, octandrous; segments of the perianth bluntly keeled, wingless. 



Cultivated grounds. Can. to Car. W. to Miss. July— Sept. (^I.—Stem 

 3—6 feet long, climbing. Flowers whitish or reddish, in terminal interrupted 

 leafy racemes. Introduced ? Black Bindweed. 



17. P. cilinode Mich. : stem climbing or prostrate, retrorsely pubescent; 

 leaves somewhat hastate-cordate, acuminate; stipules somewhat acute, 

 ciliate at the base ; flowers in axillary paniculate racemes, octandrous ; 

 segments of the perianth bluntly keeled, wingless; styles 3. 



Rocky hills. Mass. and N. Y. July, Aug. (T). — Stem 4 — 8 feet long, pur- 

 plish. Flowers greenish or pale rose-color, in slender nearly naked racemes. 

 Distinct from the preceding. Fringe-jointed Knotweed. 



18. P. dumetoruvi Linn. : stem climbing, smooth ; leaves broad-cordate, 

 acuminate ; stipules truncate, naked ; flowers rather large, in erect axillary 

 racemes, octandrous ; segments of the perianth winged. L. scandens Linn. 



Shady woods. N. Y. to Car. W. to Miss. July, Aug. (J).— Stem 6—12 

 feet Jong, often purple. Flowers white or reddish, in axillary racemes. 



Climbing Buckwheat. 



19. P. Fagopi/ruvi Linn.: stem erect, paniculately branched, smoothish; 

 leaves cordate-sagittate, acute ; rat^emes terminal and axillary ; seeds 

 equally triquetrous, nearly naked. 



Fields, remaining as a weed where it has been cultivated. June. (!)• — ^l^m 

 2 — 3 feet high, pubescent at the joints. Flowers white tinged with green and 

 purple, in somewhat paniculate racemes. Buckwheat. 



