184 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Perennials. . 
Perianth narrowed into a long stipelike base, pubescent. 
Perianth whitish; styles hairy at least to the middle....18. LE. jamesii. 
Perianth bright yellow; styles hairy only at the base....19. 2. bakeri. 
Perianth not narrowed into a stipelike base, pubescent or 
glabrous. 
Ovaries and fruit pubescent. 
Stems leafy; perianth 6 mm, long..._..............- 20. E. longifolium. 
Stems not leafy, scapelike; perianth 3 mm. long or less. 
Inflorescence an open cyme 10 to 15 cm, high; 
involucres 2 mm, high.................2--.. ..-21. FB. leucophyllum. 
Inflorescence a congested cyme less than 3 cm. 
high; involucres 3 to 5 mm. high............... 22. FE. lachnogynum. 
Ovaries and fruit glabrous or nearly so, 
Involucres in a headlike cluster................00008- 23. E. ovalifolium. 
Involucres in open cymes. 
Cymes one-sided and spikelike. 
Leaves basal, abruptly narrowed at the base or 
subcordate; perianth 5 mm. Jong............ 24. FE. racemosum. 
Leaves scattered along the woody branches, 
tapering at the base; perianth 3 mm, long... .25. Z. 
Cymes dichotomous or trichotomous. 
Perianth deep dark red; stems and involucres 
glabrous; plants tall and stout............... 26. E. atrorubens. 
Perianth white, pink, or yellow, never dark red; 
stems and involucres glabrous or pubescent; 
plants various. 
Perianth densely sericeous. 
. 
ies 
wrightt. 
Leaves elliptic, acute, tomentose............ 27. E. havardii. 
Leaves orbicular, obtuse, not tomentose..... 28. E. inflatum. 
Perianth glabrous. ° 
Perianth bright yellow; leaves glabrous (all 
basal, orbicular or broadly ovate)........ 29. E. gypsophilum. 
Perianth white or pink; leaves tomentose, at 
least beneath. 
Leaves all basal, orbicular or obovate, the 
stems densely cespitose; leaves per- 
manently and densely white-tomentose 
on the upper surface. .........-.....- 30. FE. tenellum. 
At least the lower part of the stem leafy; 
stems usually not densely cespitose; 
leaves glabrate on the upper surface. 
Flowering branches leafy for only a few 
centimeters at the base, the pedun- 
cles relatively long. 
Stems and involucres tomentulose 
throughout; lobes of the involucre 
acute; leaves narrowly oblong, 
i 31. FE. ainsliet. 
Branches of the inflorescence and in- 
volucres glabrous; lobes of the 
involucre broadly obtuse; leaves 
various. 
