404 POLYGONACEAE 



Leaves elliptic or oblong 37. E. arborescens. 



Leaves linear 38. E. giganteum. 



Heads not in a compound cyme; mainland species or mostly. 



Heads terminal on the 2-forked peduncles or racemosely disposed on 

 the forks; leaves mostly ovate or roundish. 



Calyx silky ; filaments glabrous ; leaves ashy beneath 



39. E. cinereum. 

 Calyx glabrous; filaments hairy at base; leaves white-lanate 



beneath 40. E. parvifolium. 



Heads umbellate, sometimes solitary and terminal; filaments gla- 

 brous or nearly so ; leaves oblong or linear 



41. E. fasciculatum. 

 Herbaceous or mostly so, leafy only at base; heads umbellate or usually so. 



Stems not fistulous ; heads 1 or few ; seashore 42. E. latifolium. 



Stems fistulous; heads several to many. 



Leaves spreading, oblong or ovate, obtuse, ^ to 2 inches long ...... 



43. E. nudum. 

 Leaves erect, ovate to ovate-lanceolate, acute, 1 to 3 (or 5) inches 



long 44. E. datum. 



Stems with trumpet-inflated lower internodes ; involucres solitary, racemose 



45. E. indicium. 

 Caespitose. 



Involucres very angular, 5-toothed 46. E. Tcennedyi. 



Involucres not angular, in age bladdery, 6 to 8-toothed 



47. E. ochrocephalum. 



Calyx-lobes dissimilar, the outer somewhat cordate at base, attached only by the lower 

 third of the midvein; stems scape-like. 



Stems bearing a single head 48. E. ovalifolium. 



Stems bearing a simple or irregularly compound umbel 49. E. proliferum. 



B. Calyx stipe-like at base. 



Involucres turbinate, 4 to 8-toothed or lobed, either solitary or borne in umbels, the umbels 

 sometimes congested in heads; flowering stems scape-like; perennial herbs; mountains 

 from middle altitudes to alpine. Subgenus EUERIOGONUM. 

 Involucres with re flexed lobes, the lobes often long. 

 Calyx hairy. 



Peduncles scape-like, bearing a solitary involucre, rarely an umbel. 

 Calyx yellow. 



Peduncles naked 50. E. caespitosum. 



Peduncles bearing a whorl of bracts at the middle. . . .51. E. douglasii. 



Calyx whitish 52. E. sphaerocephalum. 



Peduncle bearing a 3-rayed umbel 53. E. tripodum. 



Calyx glabrous. 



Peduncles bearing a solitary involucre 54. E. sislciyouensis. 



Peduncles bearing a simple or compound umbel. 

 Peduncles scape-like, erect or nearly so. 



Leaves mostly spreading, % to 1 inch long; umbel simple or compound. 



Leaves more or less tomentose 55. E. umbellatum. 



Leaves glabrous 56. E. torreyanum. 



Leaves erect, 1 to 3 inches long; umbel compound. . .57. E. compositum. 



Peduncles decumbent 58. E. lobbii. 



Involucres with short erect teeth. 

 Involucres in heads or umbels. 

 Calyx villous or hairy. 



Leaves glabrous 59. E. pyrolae folium. 



Leaves hairy 60. E. latens. 



Calyx glabrous. 



Bracts mostly linear, abundant 61. E. ursinum. 



Bracts small, inconspicuous. 



Eays % inch long or less, or umbels capitate ; crown compact 



62. E. incanum. 



Eays y 2 to 1% inches long; crown loose 63. E. marifolium. 



Involucres solitary. 



Calyx whitish or pinkish 64. E. Tcelloggii. 



Calyx yellow 65. E. alpinum. 



