POLYGONACEAE. 127 



Oxyria digyna (L.) Hill. Mountain Sorrel. Leaves fleshy, broadly reni- 

 form, often emarginate, 2-5 cm. broad; stems 8-30 cm. high: fruit orbicular, 

 usually bright red. 



In rocky places in the mountains. 



159. RUMEX. Dock. 



Perennial or annual leafy-stemmed herbs, some species slightly 

 woody; stem grooved, mostly branched; leaves entire or undu- 

 late, fiat or crisped; sheaths usually cylindric, brittle, soon falling 

 away; inflorescence of simple or compound often panicled 

 racemes; flowers green or reddish, perfect, dioecious or polygamo- 

 monoecious, whorled, on jointed pedicels; calyx 6-parted, the 

 three outer sepals unchanged in fruit, the three inner ones mostly 

 developed into valves which are entire, dentate or fringed with 

 bristle-like teeth; stamens 6; stigmas tufted; akene 3-angled, the 

 angles more or less margined. 



Flowers dioecious; leaves hastate; plant small. R. acetosella. 



Flowers not dioecious; leaves not hastate; plant coarse. 

 Outer sepals without tubercles; leaves crisped, oblong, 



truncate at base. R. occidentalis. 



Outer sepals, or some of them with tubercles; leaves 

 neither crisped, nor oblong, nor truncate. 

 Sepals with slender teeth. 



Annual; tubercles 3; pedicels very short. R. maritimus, 



Perennial; tubercle 1; pedicels long. R. obtusifolius . 



Sepals entire or nearly so. 



Leaves flat, all lanceolate. R. mexicanus. 



Leaves undulate, the lower cordate. 



Valves 4-6 mm. long; pedicels longer. R. crispus. 



Valves 2 mm. long; pedicels not longer. R. conglomeratus . 



Rumex acetosella L. Sheep Sorrel. Dioecious, widely spreading by 

 creeping rootstocks; stems slender, 10-30 cm. high simple or somewhat 

 branched; leaves 3-10 cm. long, very acid, glabrous, mostly hastate, the basal 

 lobes entire or toothed; sheaths scarious, becoming cut into lobes; panicle 

 narrow, the branches ascending; bracts wanting; flowers small, on short jointed 

 pedicels, clustered; sepals remaining small, much shorter than the 3-angled 

 akene. 



A common and troublesome weed. 



Rumex occidentalis Wats. Stout, 100-150 cm. tall; leaves oblong-ovate, 

 mostly obtuse, 15-40 cm. long, entire or undulate, cordate at the base; petioles 

 of the lower leaves long and slender, of the upper stout; panicles 30-60 cm. 

 long, dense, usually reddish; flowers on slender pedicels, 1 cm. long; valves 

 broadly ovate, obtuse, more or less toothed, _6— 10 mm. long, wholly without 

 tubercles; akene brown, 4 mm. long. 



Common, especially in wet meadows near the seashore. 



Rumex maritimus fueginus (Phil.) Dusen. Minutely pubescent; stems 

 erect or procumbent, branched, 15-60 cm. high; leaves linear-lanceolate, 

 truncate or slightly cordate at base, 3-10 cm. long, wavy-margined; panicle 

 dense, the flowers short-pedicelled in numerous close whorls; valves ovate, 



