POLYGONACEJS. (BUCKWHEAT FAMILY.) 317 



usually 1 or 2 inches high : leaves linear-oblanceolate, hirsute : bracts un- 

 equal : involucres in the forks on slender pedicels, the rest more nearly ses- 

 sile : flowers light rose-color. From Wyoming to Nevada. 



3. OXYRIA, Hill. MOUNTAIN SORREL. 



Flowers perfect. The two inner sepals erect, appressed, and unchanged in 

 fruit. Stamens 6. Perennial alpine and arctic herbs, erect, with long- 

 petioled round-reniform mostly radical leaves, and small obliquely truncate 

 sheaths : flowers small and greenish, in narrowly panicled racemes. 



1. O. digyna, Campdera. Rather stout and fleshy, 3 to 18 inches high, 

 glabrous : flowers in scarious-bracted fascicles, on short capillary pedicels : 

 sepals often reddish, the outer narrower and carinate. At high altitudes in 

 cold wet places among rocks throughout the northern hemisphere. 



4. RUM EX, L. DOCK. SORREL. 



Flowers perfect, polygamous, or dioecious. Inner sepals somewhat colored 

 and becoming reticulated (valves) in fruit. Stamens 6. Coarse perennial 

 herbs : stems leafy, with obliquely truncate cylindrical naked sheaths : flowers 

 small, fascicled or verticillate in paniculate racemes. 



1 . Flowers perfect or polygamous : vnlves enlarged, often bearing a grain-like 

 callosity on the back : leaves never hastate, pinnately many-veined, rarely very 

 acid. DOCKS. 



* Valves wholly without grains, mostly very large (3 lines long or more), entire or 

 denticulate : pedicels long, jointed near the base : glabrous. 



1. R. V6I1OSUS, Pursh. Stems erect, afoot high or less, from running 

 rootstocks, stout and leafy, with conspicuous dilated stipules : leaves on short 

 but rather slender petioles, ovate or oblong to lanceolate, 3 to 6 inches long, 

 only the lowest acute or somewhat cordate at base : panicle nearly sessile, short, 

 dense in fruit : valves entire, cordate-orbicular with a deep sinus, 9 to 12 lines in 

 diameter, bright rose-color. From Colorado and Nevada to British Columbia 

 and the Saskatchewan. 



2. R. OCCidentalis, Watson. Tall and rather slender, often 3 to 6 feet 

 high : leaves oblong-lanceolate, the lowest sometimes ovate, usual!)/ narrowing 

 gradually upward from the truncate somewhat cordate base, not decurrent on the 

 slender often elongated petiole, oflen a foot long or more : panicle narrow, elon- 

 gated, nearly leafless : valves broadly cordate, with a very shallow sinus, 3 lines 

 in diameter, often denticulate near the base. Proc. Amer. Acad. xii. 253. 

 R. longifolius of authors, not of DC. From New Mexico and Colorado to 

 Labrador and Alaska. 



* * Valves smaller, one or more of them grain-bearing. 



3. R. salicifolius, Weinman. Slender, often low, 1 to 5 feet high, usu- 

 ally branching and decumbent at base, glabrous: leaves narrowly or linear- 

 lanceolate, or the lowest oblong, 3 to 6 inches long, attenuate into a short peti- 

 ole, not undulate, glaucous : panicle usually open, the flowers crowded upon the 

 branches : valves ovate-rhomboidal to broadly deltoid, entire or denticulate, usually 

 with very large callosities. Across the continent and northward to Alaska. 



