BUCKWHEAT FAMILY 213 



Leaf-blades elliptic or oval, not strongly revolute; scape 1-3 cm. Ions?. 



Perianth yellow; lobes of the involucres lanceolate, more than twice as long as the 



tube. 30. E. longilobum. 



Perianth Vhite or pinkish; lobes of the involucres not twice as long as the tube. 

 Lobes of the involucres oblong or ovate, with a more or less scarions white or 



pink margin. 31. E. Shocklcyi. 



Lobes of the involucres triangular, not scarious-margined. 



32. E, pulvinatum. 



Leaf-blades linear-oblong, strongly revolute; scape none or very short. 



33. E. acaule. 



VIIL HETEROSEr,AL.\. 



Heads severaU cymose-proliferous, the central head sessile. 34. E. proliferum. 



Heads sohtary. 



Involucres about 7 mm. long; leaf-blades oval. 35. E, orthocaulon. 



Involucres 4-5 mm. long. 



Perianth bright yellow or in age purpUsh; leaf-blades about as broad as long. 



3G. E. ovalifoliurn. 



Perianth cream-colored, ochroleucous. or isabel-colored. 



Perianth 2.5-3.5 mm. long; leaf-blades rounded-oval or ovate. 



37. E. depressum. 



Perianth 4-5 mm. long; leaf-blades elliptic, oblong, or spatulate. 



38. E, ochroleucum. 



IX. Capitata. 



Perianth yellow. ^ ^j., ,*^i.,i,«.*u 



Bracts and involucres membranous; the former broadly lanceolate; the lobes of the 



latter ovate or triangular; densely pulvinate-cespitose perennials. 

 Perianth bright yellow. 39. E. chrysnps. 



Perianth ochroleucoxis. sometimes tinged with rose. 40. E. Ktngii, 



Bracts and involucres firm; the former subulate or narrowly lanceolate (except in 



E. medium): the lobes of the latter lanceolate; perennials with a cespitose 



woody caudex. _ , 



Perianth ochroleucous. 41. E. loganum. 



Perianth golden yellow. . -. 



Leaf-blades oblanceolate or oblong, tomentose on both sides. 



42. E. chrysocephalum. 



Leaf-blades linear or narrowly linear-oblanceolate. in age greener above. 



43. E. medium. 



Perianth wliite or rose-colored. 



Perianth glabrous; perennials with a cespitose woody caudex. 



Lobes of the involucres lanceolate, acute, not scarious-margined. 



Heads about 1 cm. broad; perianth fully 3 mm. long; leaf-blades 3-8 cm. long. 



44. E. Brandegei. 



Heads about 0.5 cm. broad; perianth about 2 mm. long; leaf-blades 1-2 cm. 

 long. 45. E, depauperatum. 



Lobes of the involucres oval to orbicular, scarious-margined. 



Leaves glabrate above; perianth 3-5 mm. long: involucres in small heads. 



Lobes of the involucres much shorter than the tube. 



46. E. coloradense. 



Lobes of the involucres about as long as the tube. _ 



47. E. pauciflorum. 



Leaves white-tomentose on both sides; perianth 2.5 mm. long; involucrei 

 solitary. 48. E. mancum. 



Perianth pubescent. . , , - . ^ x. n 



SufTruticose leafy-stemmed perenmal, with decumbent branches, villous. 



49. E. multiceps. 



Pulvinate perennial, acaulescent. silky -hirsute. 50. E. villi florum. 



X. Elata. ^ , 



One species. 51. E. elatum. 



XL Fascicul.\ta. ^ ,.^ ,. 



One species. -52. E. pohfohum. 



XII. DICHOTOMA. 



Stem leafy, suffrutescent ; outer perianth- segments suborbicular. , 



53. E, niveum. 



Stem scapiform. with a cespitose woody caudex; outer perianth-segments oval. ■ 

 Inflorescence more or less floccose. ^ , . « j. ^^A\^n. 



Involucres b-% mm. long; branches of the inflorescence ascendmg-spreadmg. 



54. E. dichotomum. 



oo. E. lachnoslegium. 

 56. E. strictum. 



Involucres 3-4 mm. long; branches of the mnorescence s 



erect. 

 Inflorescence glabrous. „,,, ^ 



XIII. CORYMBOSA. 



mches of the inflorescence not grooved. 



Perianth yellow. ^ , ^ . ^i. ,-i 



Plants more than 2 dm. high ; leaves not heath-like. 

 Leafy shrubs; inflorescence shorter than the stem. 



Leaf-blades elUptic. oval, or broadly spatulate; involucres glabrous. 



57. E. aureum. 



Leaf-blades oblanceolate; involucres tomentose. 58. E. idahoense. 



