104 
POLYGONACEAE. 
Inflorescence glabrous, lax with spreading branches; involucre 2-2.5 
mm. long. 30. E. salicinum. 
Inflorescence less compound; branches and internodes short, mostly 
spreading. 35. E. microthecum. 
Leaf-blades linear, revolute. 36. E. Simpsonii. 
Dwarf depressed undershrubs, less than 1 dm. high, with heath-like leaves. 
37. E. contortum. 
IX. Annua. 
One species. 
X. Virgata. 
38. E. annuum. 
Leaves crowded on the ends of the short caudex; blades abruptly narrowed at 
the base or subcordate. 39. E. racemosum. 
Leaves scattered on the fruticose branches; blades tapering at the base. 
40. E. Wrightii. 
XI. Pedunculata. 
Perianth glabrous. 
Scapes and branches glabrous. 
Peduncles erect or ascending. 
Perianth-lobes nearly equal and similar; leaves glabrous. 
41. E. Gordonii. 
Perianth-lobes very unequal and dissimilar; leaves floccose beneath. 
Outer perianth-lobes dilated above; involucres about 1.5 mm. long. 
42. E. rotundifolium. 
Outer perianth-lobes not dilated above; involucres about 3 mm. long. 
43. E. tenellum. 
Peduncles reflexed or defiexed. 44. E. cernuum. 
Scapes and branches villous or glandular, especially near the nodes. 
45. E. trinervatum. 
Perianth glandular or pubescent. 
Scapes and branches glandular, especially near the nodes, not inflated. 
48. E. glandulosum. 
Scapes and branches glabrous; upper portion of the lower internodes of the 
scape inflated. 
Accessory branches at the lower forks of the inflorescence many and nearly 
as strong as the three main branches ; branches divaricate. 
46. E. fusiforme. 
Accessory branches at the lower forks of the inflorescence none or few 
and small; branches ascending. 47. E. indatum. 
XII. Divaricata. 
One species. 49. E. divaricatum. 
XIII. Foliosa. 
One species. 50. E. salsuginosum. 
1. Eriogonum alatum Torr. In sandy soil from Neb. and Wyo. to Tex. and 
Ariz.—Alt. 4000-10,000 ft.—Headwaters of Clear Creek and alpine ridges 
east of Middle Park; plains and foot-hills near Boulder; Green Mountain 
Falls; Sand Creek Pass; South Park; Williams’ Canon, near Pike’s Peak; 
Sangre de Cristo Creek; Table Rock; Pagosa Springs; Thompson’s Park, La 
Plata Mountains; Spring Canon; Dillon Canon, near Trinidad; plains, near 
foot-hills, Larimer Co. 
2. Eriogonum triste S. Wats. ( E . alatum glabriusculum Torr.) In sandy 
soil from Colo, to Tex. and N. M.—North Park; headwaters of Clear Creek 
and alpine ridges east of Middle Park. 
3. Eriogonum Jamesii Benth. On plains and hills from Kans. and Colo, to 
Tex. and Ariz.—Alt. 4000-9000 ft.—Headwaters of Platte River; Colorado 
