CHAPTALIA. 197 



light and thin tomentum : scapes stout, a foot high, naked, 

 flocculent : involucre large, many-flowered, almost hemispherical 

 at flowering, bracts very narrow, numerous : achenes minutely 

 and sparsely pubescent along the ribs, and more minutely gran- 

 ular-scaberulous between them ; stipe of pappus filiform, very 

 long. 



Bolivian species; Rasby's n. 1677 from Mapiri and Bang's 

 237 from Yungas, both as in U. S. Herb. 



Icianthus and Sprengeria. 



Under these names I am about to propose two other genera of 

 Cruciferae. 



Icianthus has for its type species what Hooker named Strep- 

 tanthus hyacinihoides, a Texan annual which, in the Torrey and 

 Gray Flora, was mistakenly appended to that section of Strep- 

 tanthus to which Nuttall has assigned the generic or subgeneric 

 name EucUsia ; a group marked by many characters of the calyx 

 and corolla, and to which the type now in hand can by no means 

 rationally be referred, its calyx not being thin, or inflated, or in 

 the least degree bilabiate. In Icianthus the calyx is (1) not 

 in the least inflated, (3) its sepals are thick and fleshy, (3) 

 straight to their tips, (4) forming a regular calyx (5) none of the 

 sepals connivent at apex. The petals have (6) not the broad 

 and deeply channelled claw, nor (7) the short and somewhat 

 rounded limb of EucUsia. 



The species of Icianthus are perhaps several, and more than 

 are here indicated. 



I. htaciN'THOIDBS. Streptanthus hyacinihoides, Hook. Bot. 

 Mag. t. 3516. EucUsia hyacinihoides, Small, Fl. 485 in part 

 Species exclusively Texan, bearing long loose racemes of rather 

 small nodding flowers of a dull greenish purple. 



I. SLABRIFOLIUS. Streplanthus glabrifolius, Buckley, Proc. 

 Philad. Acad. 1861, p. 448 must needs be distinct by its short. 

 crowded racemes of quite large flowers said to be rose-purple. 



