148 POLYGONACBAE (BUCKWHEAT FAMILY) 



BRACTS TERNATE, NOT FOLIACEOUS. 

 FLOWERS NOT YELLOW. 



Peduncles unbranched, terminated by a capitate cluster 

 of involucres. 

 Leaves white-tomentose. > i - ! i ' 



Oval or elliptic. ; 



Outer perianth-segments suborbicular . . 19. E. ovalifolium. 

 Outer perianth-segments oblong . . .20. E. oohroleucum 



Oblanceolate 21. E. multioeps. 



Leaves glabra te above, linear 22. E. pauoiflorum. 



Pedimcles branching di- or trichotomously, often sev- 

 eral times. 

 Oaudex subterranean; leaves clustered on its crowns. 

 Peduncle simple or simply dichotomoua. 



Sepals dissimilar 23. E. tenellum. ) 



Sepal^ similar . , , , 24. E. racemosum. 



Peduncle di- or trichotomously branched . , 25. E. Siihpsonii. 

 Caudex woody, branched, leafy. 



Branches few, erect, leafy up to the short corymbose 

 cyme. 

 Leaves elliptic, undulate-dentate , . , 36. E. Jonesii. 

 Leaves linear-oblong, entire .... 27. E. salinum. 

 Branches numerous; peduncle long and naked, 

 bearing a repeatedly forked cyme. 

 Styles and stamens included .... 28. E. effusum. 



Styles exserted 29. B. corymbosum, 



FLOWERS YELLOW. 



Involucres in terminal capitate clusters. 

 .Leaves short, less than 2 cm. 



Oval to elliptic 19. E. ovalifolium. 



Oblong. 



Ovary pubescent above 30. E, caespitosum. 



Ovary glabrous 31. E. andmum. 



Leaves 4-8 cm. long, oblanceolate .... 32. E. chrysocephalum. 

 Involucres in a dichotomous cyme. 



Cyme short, subumbellate 33, E, orendense. 



Cyme long, freely branched ' 34, E, campanulatum, 



1. Eriogonvun annum Nutt. Trans. Am. Phil. Soc. II. 5: 164. 1833-37. 

 Annual, white flocdose-tomentose throughout, rather stout, simple or branched, 

 3-8 dm. high: leaves narrowly oblanceolate or oblong, attenuate to a short 

 petiole, mostly flat: inflorescence cymose: the flowers white: the perianth- 

 segments very unequal, the outer oblong-obovate. — Montana to Texas and 

 Mexico. 



2. Eriogonum salsuginosum Hook. Kew Journ. 5: 264. 1853. Low gla- 

 brous annual 4-12 cm. high: stem leafy, di- or trichotomously divided: leaves 

 spatulate-oblanceolate, the bracts becoming linear: involucres divided: 

 flowers pubescent, yellow: sepals narrow, closely appressed to the acutely 

 triangular glabrous achene. — From southwestern Colorado to Utah and west- 

 ern Wyoming. 



3. Eriogonum inflatum Tqrr. Frem. 2d Rep. 374. 1845. Glabrous annual, 

 diiTusely branched above, 1-3 dm. high, one or more of the intemodes of the 

 stem much inflated: leaves all radical or nearly so, rounded, usually cordate 

 and mostly undulate, pubescent: involucres few-flowered, smooth; the teeth 

 erect: flowers yellowish, pubescent; the pedicels about 1 mm. long; the achene 

 twice as long. (E. fusiforme Small, Bull. Torr. Bot. Club 33: 56. 1906.)— In 

 dry desert districts; southwestern Colorado to Arizona. 



4. Eriogonum Gordonii Benth. in DC. Prodr. 14: 20. 1856. Annual, gla- 

 brous throughout, or the petioles slightly pubescent: leaves basal, long- 

 petioled, broadly ovate: peduncle di- or trichotomously slender branched, 

 15-30 cm. high: involucre broadly campanulate, 5-toothed: flowers glabrous, 

 light rose-color: outer sepals ovate; the inner oblong. — Rare; in the region of 

 the Platte in Nebraska, and in Colorado and Wyoming. 



5. Eriogonum cernuum Nutt, Journ, Acad, Phila, II. 1 : 162, 1848, Gla- 

 brous a,nnual, diffusely di- or trichotomously branched, 1-3 dm, high: leaves 

 broadly ovate, acute: involucres turbinate-campanulate: pedicels deflexed: ca- 

 lyx white, campanulate, 1 mm, long, 6-parted; the segments narrowed near 

 middle; the outer ones broader above and retuse: achene rounded at base and 

 rough on the angles, — Frequent throughout our range. 



