REVISION OF RUMEX. 79 
reflexed even in flowering; valves orbicular, 5 mm. in 
diameter, clawless, usually with a delicate callosity at base; 
acbene 1.2x2.5 mm. —Sp. i. (1753), 337; Meisner, DC. 
Prod. xiv, 64.— Apparently indigenous from Labrador to 
Lake Superior, Alaska, and Oregon; and introduced from 
the Old World at a few points in the Northern States 
probably as a waif from gardens, in which it is sometimes 
cultivated for its acid foliage. — Specimens examined from 
Labrador (Bryant, 1860), Toronto (Macoun, 1878) and 
Point aux Pins, Canada (Macoun, 1869, 84), N. Shore 
L. Superior ( Pitcher), Quatcho Lake (Dawson, 1876), 
Morley (Macoun, 1885), and Arctic N. A. (&ichardson on 
Franklin Exp.), Alaska (hb. Dep. Agr.), Vancouver Isl. 
( Macoun, 1887), Oregon ( Hall, 1871, 442; Howell, 1882), 
Charlotte, Vt. (Pringle, 1877, 1879), Penn Yan, N. Y. 
( Wright), and Brookfield, Pa. ( Canby, 1862).—Plate 16. 
§§§ Lapathum.— Hermaphrodite or andro-monoecious: inner segments 
of perianth (valves) commonly reticulated, becoming round or elongated 
and much larger than the achene: leaves only exceptionally acid, never 
hastate: inflorescence with stouter sometimes leafy branches.— Peren- 
nial except R. persicarioides and R. bucephalophorus. 
* Valves at most very minutely erose or low-denticulate. 
+ Valves very large (15 to 50 mm. long), mostly rosy, round or broadly 
ovate, deeply cordate, without callosities: whorls rather remote 
but overlapping in fruit: outer sepals at length reflexed: stipular 
sheaths very large and loose. 
« 
5. R. venosus, Pursh.— A span to mostly about a foot 
high (from deep-seated thin roots?), branching from most 
of the axils and spreading, glabrous; leaves firm, not wavy, 
at most 5x10 cm. elliptical or elliptical-ovate, abruptly 
acute at both ends; inflorescence nearly simple, leafless, 
the short zigzag branches divergent; pedicels rather stout, 
about as long as the fruit, tumidly jointed below the middle ; 
valves rather firm, orbicular or broader than long, 20 to 
50 mm. in diameter, the sinus often closed, emarginate to 
shortly blunt acuminate ; achene 4x7 mm.— FI. ii. (1814), 
733; Meisner, DC. Prod. xiv.— Dry sandy soil in the plains 
