Genus 3. 



BUCKWHEAT FAMILY. 



659 



17. Rumex persicarioides L. Golden Dock. 

 Fig. 1613. 



Rumex persicarioides L. Sp. PI. 335. 1753. 



Annual, pubescent, pale green; stem rather stout, 

 erect and simple, or diffusely branched, I "-3° high, or 

 sometimes spreading or creeping, very leafy. Leaves 

 lanceolate, or oblong, 1-12 long, narrowed at the 

 base, or sometimes cordate, or sagittate, acute at the 

 apex, the margins undulate and more or less crisped; 

 panicle simple or compound; racemes erect, leafy- 

 bracted, mostly interrupted ; flowers densely whorled ; 

 pedicels slender, i-ii times as long as the calyx- 

 wings, jointed at the base; calyx very small; wings 

 oblong, 1" long, with 1-3 bristles on each margin, 

 each bearing an ovoid or oblong callosity; achene 

 less than 1' long, pointed, reddish, smooth, shining, 

 its faces convex, its angles slightly margined. 



On sandy shores, New Brunswick to Virginia, extend- 

 ing across the continent to British Columbia, south in 

 the interior to Kansas and New Mexico and on the 

 Pacific Coast to California. Has been confounded with 

 R. maritimus L. of the Old World. July-Oct. 



4. OXYRIA Hill, Veg. Syst. 10 : 24. . 1765. 



)Low fleshy glabrous perennial herbs, with erect stems. Leaves mostly basal, long- 

 petioled, reniform or orbicular, cordate, palmately nerved, with cylindric ocreae. Flowers 

 perfect, small, green, in terminal panicled racemes. Calyx unequally 4-parted, the outer 

 segments smaller than the inner ; stamens 6, included ; filaments subulate. Ovary i-celled ; 

 ovule solitary; style short, 2-parted, its branches divergent; stigmas fimbriate, persistent on 

 the large wings of the fruit. Achene-body ovate, lenticular, broadly winged. Embryo 

 straight, borne in the centre of the endosperm. [Greek, sour, from the acid leaves.] 



Two known species, the following typical ; one in the 

 Himalayas. 



i. Oxyria digyna (L.) Hill. Mountain 

 Sorrel. Fig. 1614. 



Rumex digynus L. Sp. PI. 337. 1753. 

 O. digyna Hill, Hort. Kew. 158. 1768. 

 Oxyria reniformis Hook. Fl. Scot. in. 1821. 



Rootstock large, chaffy ; stems scape-like, simple 

 or sparingly branched, leafless or nearly so, 2'-i2' 

 tall. Leaves reniform or orbicular-reniform, 4'-ii' 

 wide, undulate, sometimes emarginate at the apex, 

 the basal long-petioled ; ocreae' oblique, loose, those 

 on the stem bearing flowers; racemes many- 

 flowered; flowers slender-pedicelled ; segments ob- 

 long, the inner erect, the outer reflexed in fruit; 

 achene-body pointed, smooth, surrounded by a broad 

 membranous wing. 



Greenland and Labrador to Alaska, south to the White 

 Mountains of New Hampshire and in the Rocky Moun- 

 tains to Colorado and to California. Also in northern 

 Europe and Asia. Sour dock. July-Sept. 



5. POLYGONUM [Tourn.] L. Sp. PI. 359. 1753. 



Annual or perennial, often somewhat shrubby herbs, with terete, but usually striate 

 erect or prostrate stems. Leaves alternate, leathery or somewhat fleshy, sometimes plicate, 

 articulated to the ocreae. Ocreae lobed when young, at length lacerate, hyaline, not fringed. 

 Inflorescence axillary, consisting of clusters bearing normally several flowers at each node 

 throughout the plant or confined to the branches and branchlets. Sepals 5 or 6, mostly 

 green with white or pink or yellow margins, 2 wholly interior, 2 wholly exterior and 1 with 

 one edge exterior and one edge interior. Stamens varying from 3 to 8, often 5 or 6, in- 

 cluded ; filaments, at least the inner ones, dilated. Styles 3, usually distinct, sometimes very 

 short. Achenes 3-angled, included or slightly exserted, brown or black, granular or smooth 

 and shining. Endosperm horny. Cotyledons incumbent. [Greek, many-knees, from the 

 swollen joints of some species.] 



About 100 species of wide geographic distribution. Besides the following, some 10 others occur 

 in the western parts of North America. Type species : Polygonum aviculare L. 



