BUCKWHEAT FAMILY. 131 



3 to 5, yellowish, tinged with red, % line long; achenes triangular, exserted. — 

 (Eriogonum hirtiflorum Gray.) 



Scott Valley, Lake Co.; Mt. Diablo and Mt. Hamilton; Sierra Nevada. 



0. ixermis Wats. Bracts 2 or 3 lines long; involucres shortly pediceled, 

 4-cleft nearly to the base, awnless; flowers rose-color, % line long; inner seg- 

 ments smaller and. retuse. — Type locality supposedly Mt. Diablo. 



5. ERIOGONUM Michx. 

 Annual or perennials with radical or alternate or whorled leaves without 

 stipules, those of the inflorescence commonly reduced to bracts. Flowers per- 

 fect, involucrate. Involucre 4 to 8-toothed or -lobed, several to many-flowered; 

 pedicels more or less exserted, intermixed with narrow scarious bractlets. 

 Calyx 6-parted or -cleft, colored, persistent about the achene. Stamens 9, 

 inserted on the base of the calyx. Styles 3 ; stigmas capitate. Achene tri- 

 angular, except in a few species. "Embryo straight, in the axis of scanty 

 endosperm; cotyledons foliaceous. (Greek erion, wool, and. gonu, knee or 

 joint, the nodes hairy in some species.) 



A. Involucral lobes becoming reftexed; calyx narrowed to a stipe-like base. 

 Involucres turbinate, deeply lobed, disposed in a simple or compound umbel raised on a 

 scape-like peduncle from a leafy perennial and more or less woody base; filaments 

 hairy below. 

 Woody base much branched; leaves obovate to oblanceolate, acute, / 2 to 1 in. long.... 



1. E. stellatum. 



Woody base very short and simple; leaves oblong-ovate, cordate at base, l/ 2 to 2 in. 



long 2. E. compositian. 



B. Involucral teeth erect; calyx not attenuate at base. 

 Involucres cylindric-turbinate or prismatic, with erect teeth, always sessile, either dis- 

 posed in heads in a cymose panicle or umbel-like inflorescence, or solitary and scat- 

 tered along the virgate branches; filaments usually glabrous. 



Shrubby; leaves with revolute margins 3. E. pari'ifolium. 



Herbaceous or mostly so. 



Peduncles scape-like; involucres capitate-clustered; perennials. 



Heads 1 to 3 or 4, large and terminal, or the peduncle forked and umbel-like; 



bractlets densely villous-tomentose 4. E. latifolium. 



Heads scattered in an ample cymose panicle; bractlets glabrous 5. E. nudum. 



Stems parted from the base or above the base into mostly elongated flowering branches, 

 along which the solitary involucres are scattered, rarely 2 to several in a cluster. 

 Perennials with short woody stems which are densely leafy. 



Leaves obovate or oblanceolate, acute; bracts all small and triangular 



6. E. trachygonuin. 



Leaves roundish ; lower bracts subfoliaceous 7. E. saxatile. 



Annuals; leaves mostly in a rosette at base. 



Inflorescence somewhat umbel-like, the 2 to 4 rays once or twice di- or tri-choto- 



mous, or 1 or 2 simple 8. E. truncatum. 



Plants for the most part di- or tri-chotomously parted from the base or the 



middle, with the flowering branches much elongated and the involucres 



scattered along them. 



Involucres narrow or turbinate, 1 to 1 y 2 lines long; flowers glabrous; often 



diffusely branched. 



White-woolly throughout; teeth of the involucre prominent. ... 10. E. gracilc. 



Stems and inflorescence glabrous; teeth of the involucre inconspicuous 



9. E. vimincum. 

 Involucres cylindric, 2 lines long. 



Flowers glabrous; erect and strictly branched 11. E. virgatum. 



Flowers villous on the outside; more or less umbellately branched, sometimes 



very diffuse 12. E. dasyanthonum. 



Involucres turbinate, on filiform pedicels; panicle repeatedly dichotomous, commonly leafy 

 at the nodes 13. E. angulosum. 



1. E. stellatum Benth. Somewhat tomentose, the leaves densely tomen- 

 tose on both sides or glabrate above; peduncles naked from a diffusely branched 



