POLYGONACE^ 35 



3. C. livida, Richards. 



Stems slender, 4-10 in. high; leaves oval, thin, short-petioled ; cymes 

 axillary, not numerous, and few-flowered; fruit red, globular, the calyx 

 teeth persisting as a crown. Bogs and mountains, N. Man.-Alta. 



XXIII. POLYGON ACE^ (Buckwheat Family). 



Herbs with alternate entire leaves and stipules sheathing the 

 stem above the swollen joints; flowers perfect, usually with per- 

 sistent calyx; ovary 1-oelled with 2 or 3 styles or stigmas, one- 

 seeded; fruit usually a 3 or 4-angled achene. 



1. RtJMEX. Dock. 



Calyx of 6 sepals, the three inner slightly colored and enclosing 

 the 3-angled achene; stamens 6; styles 3. Coarse herbs with loose 

 racemes of small dull-colored flowers. 



1. R. venSsus, Pursh. 



Stems 1—2 ft. high from a creeping rootstock; leaves oblong to lanceolate, 

 petioles slender, stipules dilated; raceme short and dense, appearing pink 

 in fruit from the color of the sepals enclosing the achenS. Light soil, W. 

 Sask. 



2. R. occidentSUs, Wats. 



Stems stout, erect, 2-4 ft. high, usually tinged with purple ; leaves large ; 

 sepals enclosing the achene large and blunt-pointed. Damp alkaline soil 

 Man.-Alta. 



3. R. persicarioides, L. Golden Dock. 



Stem S in.-2 ft. high branched, finely pubescent; leaves linear to lanceo- ^ 

 late, wavy on the margin, the lower heart-shaped at the base; inner sepals 

 with 2 or 3 spines on the back. Wet alkaline soil, Man.-Alta. 



4. R. mezicanus, Meisn. 



Erect; leaves lanceolate to oblong, pale, 

 glaucous ; panicle strict, dense ; calyx brown. 

 Alkaline soil, Man.-Alta. 



5. R. acetos6Ua, L. Sheep Sorrel. 



Stem low, 6-10 in.; leaves, or at least 

 the lower ones, halberd-shaped, sour to the 

 taste; sepals not sufficiently enlarged to en- 

 close the achene, dull reddish in fruit. Sandy Fig. 32. — Rumex aceto- 

 Boil, introduced. sella. 



