APPENDIX. 481 



(a.) Calyx broad and truncate below, having the broad-oval outer segments distinct and subauricu- 

 late-rounded at base ; panicle often diohotomous and bracts somewhat leafy ; white-woolly. 



46. E. NiVEUM, Dougl. Woody at base, 1° high or more, densely tomentose ; stems leafy below or 

 nearly naked ; leaves ovate or oblong, petioled ; the bracts and the 3-4 subulate teeth of the densely 

 woolly involucre recurved-spreading ; outer calyx-segments becoming rounded-oval and slightly cordate, 

 enclosing the obovate-spatulate inner ones. — Oregon and "Washington Territory. 



47. E. DICHOTOMUM, Dougl. Somcwhat like the last ; branches short and densely leafy, with strict 

 scape-like rarely leafy peduncles ; leaves oblong, attenuate at base ; bracts appressed, shorter than the 

 involucre; involucre-teeth 3-5, shortish and obtuse, subequal ; outer calyx-segments obovate-oval.— 

 Oregon and S. Idaho. 



(6.) Calyx acute at base, the segments alike ; the first two species scapose and strict, the last caul- 

 escent and diffusely panicled. 



48. E. STRICTUM, Benth. CsBspitosely much-branched at base ; leaves crowded, spatulate or obovate- 

 oblong, white-woolly beneath, attenuate into a long petiole ; scapes very slender, 1° high, glabrous or 

 glabrate, 2-3-chotomously branched; bracts small, subulate, appressed; involucre 1" long, glabrate, 

 campanulate, equally 5-toothed ; calyx-segments oval or oblong. — Oregon, (Douglas.) 



49. E. EACEMOSUM, Nutt. LeavcB ovate or oblong, long-petioled, abrupt or subcordate at base ; 

 scape stout, 1-3° high ; involucres spicate along the few rigid branches. See page 304. 



50. E. WRlGHTn, Torr. Branched from a shrubby base, leafy below ; leaves narrow at base, often 

 fascicled ; involucres loosely spicate ; ovary slightly scabrous above. See page 305. 



* * Annual, (excepting perhaps E. elongatum;) flowers small, white or rose-color, acute or acutish 



at base, mostly glabrous ; bracts small, appressed. 

 (a.) Involucre tubular, 3^-2" long, many-flowered, hoary-woolly, scattered upon the virgate mostly 



simple branches, appressed; calyx-segments obovate, nearly equal. White-woolly plants, the 



at length floccose tomentum rarely deciduous. Californian. 



51. E. ELONGATUM, Beuth. Stems or branches 1^3° high, sparingly leafy at base only; leaves 

 oblong-lanceolate; involucres 3" long, rather many-flowered, spicate and distant along the simple 

 branches, repand-truncate ; ovary glabrous ; embryo 1" long or more. 



52. E. VIKGATUM, Benth. Stem more slender, sparingly leafy at the base or also above ; branches 

 few, simple, sometimes paniculately branched ; leaves ovate or oblong ; involucres 2-2^" long, 5-toothed ; 

 ovary and abruptly rostrate achenium a little scabrous above ; embryo i" long. 



(b.) Involucre narrow-tubular, few to rather many-flowered, 2" long or less, scattered on the slender 

 branohlets of the diffuse panicle, longer than the glabrous or pilose flowers ; bractlets scaxcely 

 bearded ; low, finely tomentose above or glabrous, with rounded radical leaves. 



53. E. DASYANTHBMUM, T. & G. Cinereous- wooUy or glabrate above ; involucre shortly 5-toothed, 

 commonly hoary, fully 2" long, sometimes 15-20-fiowered ; calyx finely villous, at least at base, the obo- 

 vate segments nearly equal. — California. 



54. E. VIMINEUM, Dougl. Involucres few-flowered and glabrous, as also the very slender branches 

 of the more decompound panicle ; calyx glabrous, inner segments narrower. See page 305. 



(c.) Involucre few or rather many-flowered, oblong-campanulate, subturbinate, 5-toothed, 1" long, 

 scattered upon the slender branchlets of the usually much-branched panicle ; calyx glabrous, 

 shorter than the involucre, inner segments narrow ; leaves radical or more or less cauline, white- 

 woolly beneath, floccose-wooUy above, as usually the branches and involucres. 



55. E. GRACLLB, Benth. Stem naked or leafy ; panicle open and spreading ; bractlets subglandular- 

 barbellate ; outer calyx-segments obovate, the inner oblong. See page 305. 



56. E. POLYCLADON, Bcnth. Wool persistent ; stem 2-3° high, leafy to the rather strict ample pan- 

 icle ; leaves oblong and obovate ; bractlets villous with very long delicate hairs ; calyx-segments atten- 

 uate at base, the outer fan-shaped, the inner obovate-spatulate. — W. Texas to Arizona. 



(d.) Involucre mostly short-campannlate, small, shorter than the enlarged calyx, scattered on the 

 usually tangled branchlets of the naked panicle, its teeth 4-5, broad, rounded ; bractlets chaffy ; 

 leaves subradical, rounded, long-petioled. 



57. E. Heermakni, Dur. & Hilg. Glabrous or glabrate ; calyx glabrous, becoming 2" long, outer 

 segments rounded, the inner smaller, oblong-spatulate. See page 306. 



58. E. Pldmatblla, Dur. & Hilg. Floccose-woolly, low ; calyx glabrous, 1" long, the segments 

 obovate-cuneiform, retuse. See page 306. 



59. E. INTRICATUM, Beuth. Leaves viscid-pubescent ; the divaricately much-branched panicle and 

 the very small few-flowered short-campanulate involucres glabrous; bractlets obovate- or cuneate- 



61 



