1848.] 17 



E. ^purpurea. Leaves all radical, short and roundish-ovate, whitely tomen- 

 tose ; capitulum made up of several sessile, smoothish, tomentosely margined 

 involucres; outer segments of the purple perianth orbicular, sometimes emargin- 

 ate at base ; the inner emarginate, narrow, segments scarcely exserted. 



Hab. Rock}' Mountains of the Platte. 



Scape about a span high, arising from a multifid woody caudex; flowers larger 

 than in the preceding and purple ; filaments much shorter than the perianth, with 

 a torn membranous margin at base ; three stamens seated on each of the inner 

 narrow segments ; embryo rather short. 



CHORIZANTHE. 



C. *nudicaule. Annual; radical leaves narrow spathulate, pubescent, with 

 long, slender petioles, tomentose beneath; scapiform stem nearly naked, the 

 summit trichotomous, the branchlets once or twice bifid, the flowers cymosely 

 conglomerated ; stem and very unequal toothed involucrum lanuginous ; segments 

 of the sessile, exserted perianth oblong, obtuse. 



IIab. Santa Barbara, Upper California. Flowering in April. 



C. *angustifolia. Annual and small ; leaves all linear-spathulate, softly la- 

 nuginous, as well as the branches; stem trichotomous, the heads of flowers 

 somewhat racemose ; involucrum pilose, with very unequal, uncinate spreading 

 teeth, subulate to their base; perianth minute, the segments obtuse and without 

 points. 



Hab. Pueblo los Angeles, Upper California. Flowering in April. 



C. *discolor. Annual or biennial, and rather dwarf; leaves all radical in a 

 rosulate cluster, the primary nearly smooth, rather large, spathulate-oblong, 

 obtuse or emarginate, rather smooth above, whitely tomentose beneath ; the 

 jietioles, stem and involucrum very hairy ; the involucrum with spreading, very 

 unequal teeth subulate to their base; scape low, doubly trichotomous, the flowers 

 in cymose clusters. 



Hab. St. Diego, Upper California. 



C. *procumbe7is. Annual or biennial, softly pilose ; leaves spathulate, rather 

 small ; stem nearly naked, procumbent, the branches extremely divaricate and 

 fragile, cymose ; flowers in small clusters ; involucrum with the teeth subulate 

 to the base, slightly uncinate, unequal ; perianth segments oblong, entire, (yellow) 

 pubescent. 



Hab. With the above. Flowering in April and May. (Nuttall.) 



A very remarkable species by its procurhbent habit and extreme fragility ; the 

 branchlets and clusters of flowers disjointing into numerous fragments on the 

 slightest touch, like a Loranthus. 



C. *uncinata. Like the preceding, but with the teeth of the involucrum 

 strongly and remarkably uncinate and nearly equal ; the tube is almost 

 smooth and strongly ribbed ; it is likewise yellowish, as well as the pubescent 

 perianth. 



Hab. With the above. (Nuttall.) 



^. Perianth exserted ; the segments oblong, deeply fringed towards their base, 

 (red) styles very long — *Ptilosepal4. 



C. -^Jimbriata. Annual; leaves all radical, spathulate-oval, pilose beneath; 

 scape trichotomous ; flowers in compound cymes ; involucrum pubescent, 



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