POL YGONA CEAE. 363 



falling away at maturity, fringed with long bristles; racemes narrow, erect or 

 slightly drooping, loosely-flowered, 2-8 cm. long; calyx greenish; stamens 8; style 

 2-3-parted to the base; achene oblong, thick, lenticular or 3-angled, 2.5 mm. long, 

 smooth, shining. In swamps and wet places, throughout N. Am. except the extreme 

 north. June-Oct. 



Polygonum punct^tum leptosUchyum (Meisn.) Small. Rather smaller ; stem slen- 

 der, 3-6 dm. long ; leaves narrower ; racemes very slender and much interrupted, clus- 

 tered at the summit; achene about 2 mm. long, oblong, shining. Vt. to Calif., south to 

 Fla. and Mex. 



Polygonum punct&tum robustior Small. Larger and stouter than the type, leafy ; 

 stem 6-12 dm. tall, conspicuously enlarged at the nodes ; leaves 5-20 cm. long; racemes 

 thicker, 2.5-10 cm. long, interrupted below; achene 3 mm. long, slightly granular, some- 

 what obovoid; calyx-segments white. Mass, to Fla., near the coast. 



18. Polygonum orientale L. PRINCE'S FEATHER. (I. F. f. 1335.) Annual, 

 more or less hispid; stem erect, 3-25 dm. tall, branched. Leaves ovate or broadly 

 oblong, 7-30 cm. long, petioled, acuminate at the apex, ciliate; petioles slightly 

 winged; ocreae cylindric, loose, mostly with a spreading border, ciliate; racemes 

 panicled, oblong-cylindric, 2.5-10 cm. long, dense, drooping; flowers large for the 

 genus; calyx dark rose-color or crimson; stamens 7, exserted; style 2 -cleft to above 

 the middle; achene orbicular or broader than long, lenticular, flat, 3 mm. in diam- 

 eter, finely reticulated and rather dull. In waste places, escaped from gardens 

 throughout eastern N. Am. Native of India. Aug.-Sept. 



19. Polygonum Virginianum L. VIRGINIA KNOTWEED. (I. F. f. 1336.) 

 Annual, nearly glabrous, or strigose; stem erect or arching, simple, or branched 

 above, 3-12 dm. tall. Leaves ovate, elliptic-ovate or ovate-lanceolate, short- 

 petioled, acuminate at the apex, 5-15 cm. long, sparingly ciliate; ocreae cylindric, 

 strigose, fringed with short bristles; racemes spike-like, naked, greatly elongated 

 and interrupted, sometimes 4-5 dm. long; calyx curved, greenish or rose-color, 

 4-cleft; stamens 5; style long, exserted, 2-parted to the base, its branches at length 

 curled; achene 4 mm. long, ovate-oblong, lenticular, strongly biconvex, dark 

 brown or cream-colored, shining. In woods, N. S. to Minn., south to Fla. and 

 Tex. July-Nov. 



20. Polygonum aviculare L. KNOTGRASS. DOOR-WEED. (I. F. f. 1337.) 

 Annual or commonly perennial, slender, glabrous, dull green or bluish green; stem 

 prostrate or ascending, 1-7 dm. long. Leaves oblong, linear or oblanceolate, 0.5-2 

 cm. long, jointed to the ocreae, narrowed at the base, usually acute at the apex, 

 not conspicuously veined; ocreae oblique, silvery, 2-parted or at length lacerate; 

 clusters axillary, i-5-flowered; calyx green, 5-parted, the lobes with a white or pink 

 border; stamens 5-8; style short, 3-parted to near the base; achene 3-angled, 

 ovoid, 2 mm. long, acute, reticulated. A weed in cultivated and waste grounds, 

 common almost throughout N. Am., Asia and Europe. June-Oct. 



21. Polygonum littorale Link. SHORE KNOTWEED. (I. F. f. 1338.) Annual 

 or perennial, stout, glabrous, bright green or slightly glaucous; stem 312 dm. 

 long, prostrate or ascending, diffusely branched from a woody base, striate. 

 Leaves oblong, oblong- lanceolate or oblanceolate, 0.5-2.5 cm. long, obtuse or sub- 

 acute at the apex, mostly acuminate at the base, prominently veined, often crisped, 

 jointed to the ocreae; ocreae oblique, at length lacerate; flowers axillary, 2-6 in 

 each cluster ; calyx green, its lobes whitish-margined or carmine; stamens 8; style 

 short, 3-parted to the base; achene broadly ovoid, 3-angled, 3 mm. long, more or 

 less pinched at the apex. On shores and in waste places, N. B. to Minn, and 

 Cal., south to Va., 111. and Kans. Also in Europe. Aug.-Sept. 



22. Polygonum Bellardi All. BELLARD'S KNOTWEED. (I. F. f. 1339.) 

 Annual, dingy green; stem slender, prostrate or spreading, 3-9 dm. long, often 

 diffusely branched, striate. Leaves oblong-lanceolate or linear-lanceolate, short- 

 petioled, 0.54 cm. long, acute at the apex, acuminate at the base, distant, promi- 

 nently veined beneath, jointed to the ocreae; ocreae oblique, silvery, slightly 

 lacerate when young, becoming much incised when old ; flowers 1-3 together in 

 the axils; calyx green, its lobes white-margined ; stamens 8; style 3-parted to the 

 base, very short; achene ovoid or oblong-ovoid, 3-angled, rather pointed at both 

 ends. 2-2.5 mm - l n g> reticulated and rather dull. In waste grounds, Washing* 

 ton, D. C. Adventive from eastern Europe and western Asia. 



