POLYGON ACE AE (BUCKWHEAT FAMILY) 149 



6. Eriogonum alatum Torr. Sitgr. Rep. 168. pi. 8. 1853. Loosely silky- 

 villous throughout, or the leaves nearly glabrous except on the margin and 

 midrib, perennial, rather stout, branched above, 5-10 dm. high: leaves alter- 

 nate, long-oblanceolate: involucres pedunculate, cymose at the ends of the 

 branches of the rather ample panicle, turbinate, with 5 erect teeth: flowers 

 about 2 mm. long, yellowish, nearly glabrous, abruptly contracted at the base: 

 achene winged the whole length. (E. triste Wats. Proc. Am. Acad. 10: 347. 

 1875.) Montana to Texas and Arizona. 



7. Eriogonum heracleoides Nutt. Journ. Acad. Phila. 7: 49. 1834. Tomen- 

 tose perennial, from a diffusely branched caudex, 2-5 dm. high: stems slender, 

 more or less tufted, with some sterile decumbent branches below: leaves 

 largely basal, the upper part of the stems scapose-pedunculate and bearing an 

 umbellate cluster of yellow flowers subtended by a conspicuous involucre of 

 foliar bracts; the peduncle usually with a verticil of similar bracts near the 

 middle also: leaves glabrate above or glabrous, spatulate oblong to oblanceo- 

 late: involucre 6-8-cleft: flowers pale yellow. Colorado and Wyoming to the 

 north Pacific States. 



8. Eriogonum umbellatum Torr. Ann. Lye. N. Y. 2: 241. 1828. Stems de- 

 pressed and shrubby below, much branched: leaves oblong to obovate-spatulate, 

 3-4 cm. long, petioled, white-tomentose below, green and glabrate above: 

 scapose peduncles 1-3 dm. long: umbel simple, a whorl of foliar bracts sub- 

 tending it: involucres deeply lobed, the lobes becoming reflexed: flowers yel- 

 low, glabrous. (E. neglectum Greene, Pitt. 5: 69. 1903.) Exceedingly com- 

 mon throughout our range at low or middle elevations, and westward to the 

 Pacific States. 



8a. Eriogonum umbellatum intectum A. Nels. Leaves glabrate on both 

 faces at maturity. (E. umbcllifcrum Small, Bull. Torr. Bot. Club 33: 51. 

 1896.) Same range. 



9. Eriogonum Rydbergii Greene, Pitt. 5: 68. 1892. Resembling the last 

 but lower and densely white-tomentose on leaves, peduncles, and the smaller 

 bracts: leaves elliptic-ovate or rhomboid, 1-2 cm. long: umbel simple, few- 

 rayed: flowers yellow or greenish-yellow, glabrous. Yellowstone Park, in the 

 Geyser regions. 



10. Eriogonum latum Small, Mem. N. Y. Bot. Card. 1: 121. 1900. Shrubby 

 at base and branching freely, forming mats: leaves from oblong to oval, some- 

 what floccose-pubescent below, glabrous above: scapes 2 dm. or less long: 

 umbel 3-8-rayed; bracts oblong or spatulate, at length reflexed: involucres 

 ribbed, with 6-10 unequal reflexed lobes: flowers in dense heads, pale yellow 

 or purple-tinged, tapering into a slender stipe-like base. Northwestern Wyo- 

 ming to Montana and Idaho. 



11. Eriogonum subalpinum Greene, Pitt. 3: 18. 1896. Closely resembling 

 E. umbellatum, quite as matted and more woody at base: peduncles stouter, 

 often 3-4 dm. long: leaves mostly glabrate above, rarely below also: flowers 

 pale yellow, tinged with rose in drying; the inner segments accrescent and 

 finally surpassing the outer ones. Middle elevations to timber line; through- 

 out our range. 



12. Eriogonum Bakeri Greene, PL Baker. 3: 15. 1901. The base woody, 

 branched, clothed with old leaf-bases: peduncles white-tomentose, becoming 

 glabrate, 1-2 dm. high: leaves from oval to spatulate, 2-5 cm. long, white- 

 tomentose, tending to become glabrate above: inflorescence a single large 

 sessile involucre at summit of the peduncle (scape) and from the base of this 

 a pair of rays (very variable in length) at the summit of which is another in- 

 volucre and another pair of proliferating rays (or pedicels), such prolifera- 

 tion sometimes occurring a third and even a fourth time with constantly 

 shortening rays: bracts large, resembling the leaves: flowers yellow, somewhat 

 villous; the inner segments longer than the outer. E. Jamesii flavescens. 

 [E. arcuatum Greene, Pitt. 4: 319. 1901; E. vegetius (T. & G.) A. Nels. Bull. 

 Torr. Bot. Club 31: 239. 1904.] Wyoming to New Mexico. 



13. Eriogonum Jamesii Benth. DC. Prodr. 14: 7. 1856. Rather slender, 

 herbaceous with branching caudex, 1-3 dm. high, white-tomentose : leaves and 



