t 

 Eriogonum. POLYGONACE.E. 19 



Leaves rounded : very diffusely much-branched, often gla- 

 brous : involucres and flowers very small. 50. E. BAILEYI. 



Leaves oblanceolate : more erect and virgate, tomentose : 



involucres short, turbiuate : bracts more produced. 51. E. GKACILE. 



Leaves rounded : intricately much-branched, tomentose : 

 involucres very small : flowers larger, the segments 

 broadly cuneate, retuse. 52. E. PLUMATELLA. 



1. Involucres herbaceous and nerveless, more or less broadly turbinate (mostly 

 2 lines long or more), 4. ^-toothed or -lobed : bracts foliaceous, indefinite 

 in number (2 to 5 or more). Mostly perennial. EUKKIOGONUM, Watson. 



* Involucres in a simple or compound umbel, sometimes single or capitate: peri- 

 anth attenuate to a more or less narrow and stipe-like base. Perennials, 

 often woody at base, with naked or leafy-bracteate peduncles / leaves mostly 

 woolly, at least beneath ; filaments pubescent at base ; ovary usually some- 

 what hairy above. ( UMBELLATA, Benth., & PSEUDO-UMBELLATA, Torr. 

 & Gray.) 



4 Involucres deeply lobed, the lobes becoming reflexed. 



H- Perianth villous or pubescent : involucre solitary, without bracts (rarely um- 

 belled in n. 3) : low and cespitose, with yellow jiowers, and leaves tomentose 

 both sides. 



1. E. csespitosum, Nutt. Dwarf and densely matted, the short woody caudex 

 much branched and usually crowded with old leaves : leaves ovate- to oblong-spatu- 

 late, 2 to 6 lines long, densely white-woolly, rosulate : peduncles scape-like, naked, 

 1 to 3 inches high, slender : lobes of the involucre linear-oblong, as long as the tur- 

 binate tube : flowers yellow, often tinged with purple, 1 to 3 lines long including 

 the stipe-like base ; lobes oblong-oval. Journ. Acad. Philad. vii. 50, t. 8 ; Torr. 

 & Gray, Rev. Eriog. in Proc. Am. Acad. viii. 157. 



On mountain sides and in dry valleys from Northwestern Nevada to Wyoming Territory. 



2. E. Douglasii, Benth. Somewhat larger, stouter and more diffuse, the leaves 

 sometimes an inch long : peduncles 3 or 4 inches high, with a whorl of 4 to 6 ob- 

 lanceolate leaves in the middle. DC. Prodr. xiv. 9 ; Torr. & Gray, 1. c. 



In Sierra Valley, Sierra County (Lemmon) Blue Mountains, Oregon, Douglas. 



3. E. sphaevocephalum, Dougl. Still more diffuse and leafy-stemmed ; leaves 

 usually narrower and linear-spatulate, less tomentose above and margins often revo- 

 lute : peduncles 2 to 4 inches long, with a central whorl of leaves and solitary in- 

 volucre, or the whorl subtending a 2 - 4-rayed umbel with the lateral rays also 

 bracteate: flowers bright yellow or yellowish, 2 to 4 lines long including the slender 

 stipe. Benth. 1. c. 8 ; Torr. & Gray, 1. c. 



Northern California (rocky hills about Yreka, Greene) and Nevada to Washington Territory. 



E. THYMOIDES, Benth., is most nearly allied to this group, though with the short involucral 

 lobes apparently always erect : dwarf, densely branching and woody, with revolute-linear leaves 

 1 to 5 lines long ; peduncles slender, 1 to 3 inches high, with a whorl of similar leaves in the 

 middle ; flowers densely long-villous, purplish, 2 or 3 lines long, with rather broad lobes. 

 Oregon (Union County, Cusick) and Washington Territory, Pickering, Lyall. 



H- -H- Perianth glabrous, with elongated base : peduncles from a more or less dif- 

 fusely branched woody base : umbel simple or compound (involucre rarely 

 solitary in n. 4) : leaves not large, often glabrous or glabrate at least above. 



4. E. umbellatum, Torrey. More or less tomentose, at least the upper side of the 

 leaves glabrate : leaves obovate- to oblong-spatulate or oblanceolate, an inch or two 

 long or often smaller, margins not revolute nor undulate : peduncles 3 to 12 inches 

 high or more, naked, bearing a simple umbel of 3 to 10 naked usually short rays, 

 subtended by a whorl of leaves : lobes of the involucre usually shorter than the 



