POLYGONACEAE. 109 



7. Rumex occidentalis S. Wats. In wet ground from Alb. and B. C. to 

 N. M. and Calif. Alt. 5000-8000 ft. West Cliff; Hot Sulphur Springs; 

 Steamboat Springs; Veta Pass; Mountain View, Pike's Peak; Gunnison; 

 Idaho Springs ; Pine Creek ; Twin Lakes ; Parlin, Gunnison Co. ; forks of 

 White River. 



8. Rumex densiflorus Osterh. (R. Bakcri Greene.) In wet ground in 

 Wyo. and Colo. Alt. up to 10,000 ft. Idaho Springs; North Park; Gunni- 

 son ; Fort Collins ; summit of North Park Range, Routt Co. 



9. Rumex subalpinus M. E. Jones. In swampy ground in the mountains 

 of Colo, and Utah. Alt. about 10,000 ft. Keblar Pass ; Pagosa Peak ; Cam- 

 eron Pass ; North Park ; Deadman Canon. 



10. Rumex Patientia L. Cultivated and occasionally escaped from Mass, 

 and N. J. to Utah; native of Europe. Pass Creek; Little Kate Basin (?). 



11. Rumex altissimus Wood. In valleys and wet places from Mass, and 

 Wash, to Va. and Colo. Mouth of Deer Creek. 



12. Rumex crispus L. In waste places from Newf. and Mont, to Fla. and 

 Calif. ; introduced from Europe. Alt. about 5000 ft. Fort Collins. 



13. Rumex salicifolius Weim. Along rivers and lakes from Ont. and Alaska 

 to Tex. and Calif. ; also in Mex. Alt. 4000-10,000 ft. Zola ; Sangre de Cristo 

 Creek; Calhan; Fort Collins; Cucharas Valley, near La Veta; La Plata; 

 Boulder; New Windsor; Robinson; Alamosa; Pitkin; Empire; Pueblo; 

 Steamboat Springs. 



14. Rumex obtusifolius L. In waste places from Vt. and Neb. to Ga. and 

 Colo. ; introduced from Europe. Alt. about 5000 ft. Fort Collins. 



15. Rumex persicarioides L. (R. maritimits L.) In or near water from 

 Que. and B. C. to N. C. and Calif. Parlin ; Gunnison ; Canon City ; Higho ; 

 New Windsor; Steamboat Springs; above Bents' Fort. 



3. OXYRIA Hill. MOUNTAIN SORREL. 



i. Oxyria digyna (L.) Compt. In the mountains among rocks from Greenl. 

 and Alaska to N. H., Colo., Ariz, and Calif. ; also in Europe and Asia. Alt. 

 9000-14,000 ft. Cameron Pass; headwaters of Clear Creek; Ouray; Bottom- 

 less Pit, Pike's Peak; Mt. Harvard; Red Mountain, south of Ouray; Red- 

 cliff e; Ironton; Clear Lake; Pagosa Peak; Mt. Hesperus; Chambers' Lake; 

 Berthoud Pass ; Beaver Creek ; Graymont ; Hahn's Peak. 



4. POLYGONUM L. KNOT-WEED. 

 Fruit erect. 



Inflorescence of small axillary clusters, scattered more or less throughout the 

 plant ; all with elongated stems or branches ; perianth-lobes never keeled 

 near the apex. 

 Plants copiously leafy throughout ; upper leaves scarcely reduced, more 



crowded. 

 Perianth-lobes with yellowish green margins ; plant erect with spreading 



branches in age, leaves broad, yellowish green. i. P. ercctuin. 



Perianth-lobes with white, pink or purplish margins ; plants prostrate or 



diffusely spreading ; leaves from bright to pale bluish green. 

 Leaves thick, prominently veined, usually pale ; ocrea very conspicuous ; 



faces of the achenes granular. 2. P. buxiforme. 



Leaves thin, not prominently veined, bright green ; ocrea not conspicuous ; 

 faces of the achenes finely striate. 3. P. avicitlare.. 



