476 CX. POLYGONACEZ. — 
16. P. arirouium. Hastate Knoigrass. 
St. aculeate with reversed prickles; lws. hastate; spikes few-flowered ; jis. 
distinct; sta. 6; sty. 2—@ Wet grounds, Can. to Ga. and W. States. Distin- 
guished from the last chiefly by its larger, halbert-shaped leaves, which are 
2—4’ long and 4 as wide. Petioles 4—1’ long. Clusters racemose, slender, 
loose, few-flowered, at the ends of the branches. June, July. 
17. Ps convotyvttus. Knot Bindweed. 
St. twining, angular; /vs. cordate-hastate; seg. of the cal. obtusely keeled ; 
sta, 8; sty. 3—Q Acommon climbing species, in fields and waste grounds, Can. 
to Ky. and Car. Stem 2—6f long, roughish, angled, with axillary branches. 
Leaves 1—2/ long, 4 as wide, on petioles }—3/ long, with somewhat spreading 
and acute lebes at base. Flowers whitish, in terminal, interrupted spikes; 
June—Sept. 
B. cilinode. (P. cilinode. Mz.) Plant minutely pubescent; stip. fringed with 
reflexed hairs at base. 
18. P. scanpens. Climbing Knotgrass. 
St. twining, smooth; lvs. cordate, acuminate; seg. of the cal. winged; sta. 
8; sty.3.—27 N. Eng. to Ark. Stem 3—7f long, climbing, often colored and 
with axillary branches. Leaves heart-shaped, with distinct, rounded lobes. 
Flowers in long, interrupted racemes. Calyx and fruit conspicuously 3-winged, 
the wings decurrent on the slender, jointed pedicels. Aug. 
389. P. racorYrumM. Buckwheat.—QSt. erect, smooth; lvs. cordate-sagittate ; 
fac. panicled; sta. 8; sty. 3; angles of the ach. equal—@ The name from the 
Lat. fagus, beech, and pyrum, a pear; the fruit resembles in shape a beech-nut. 
Native of Asia, but here naturalized. A valuable grain cultivated for the flour 
which is made into pan-cakes and eaten warm. Stems 2—4f high. Leaves 
2—4’ long, }as wide. Flowers numerous, white, very grateful to bees. +4 
4, RUMEX. 
Calyx persistent, of 6 colored sepals, the 3 inner (valves) larger ; 
sta. 6; sty. 3, spreading; stigmas many-cleft; achenium 3-cornered, 
covered. by the-3 valve-like inner sepals—Herbs with the flowers im 
dense, fasciculate panicles. 
§1. Lapatnem. Flowers all &. Inner sepals (valves) granuliferous. 
* Inner sepals entire. 
1. R. crispus. Yellow Dock. 
Lvs. lanceolate, waved, acute; valves Leena sepals) of the cal. entire, ovate, 
each bearing a tubercle —2 Can. and U. A weed so common as hardly to 
need description, growing in cultivated grounds, about rubbish, &c., much to 
the annoyance of the farmer. Stem 2—3f high, smooth, channeled, from a yel- 
low, fusiform root. Flowers numerous, in a large panicle, consisting of many 
racemes of half-whorls, interspersed with leaves. Calyx-valves. 3, enclosing 
the seed, each with a grain on the back. The root is used in medicine for cuta- 
neous diseases. June. § 
2. R. sancuineus. Bloody-veined Dock. F 
Iws. petiolate, cordate, lanceolate; valves of the cal. entire, one of them: 
principally bearing the granule.—?| Can. and N. States, Stem of a reddish 
color, branching, leafy, 2—3f high. Leaves smooth, radical ones large, mostly 
with red veins, somewhat cordate, slightly curled at the edges. Flowers in: 
small, distant whorls. Grows in waste and shady places. July. § 
3. R. BritTaNicus. British Water Dock. 
Lvs. broad-lanceolate ; joints with nearly obsolete, torn sheaths; fs. poly- 
gamous; valves entire, all bearing granules.— | Can., U.S. Aquatic, growing. 
in muddy places. Root yellow internally, large. Stem 3f high, furrowed, 
angular and branched. Leaves large, petiolate, acute. Flowers in verticillate 
fascicles, collected into a large, terminal panicle. Pedicels nodding in fruit.. 
Calyx valves large, cordate. July. 
