346 DESCRIPTIONS OF NEW SPECIES 



ments of the leaves, which are nearly smooth above, all of them linear, with 

 the fruit lanceolate, acute, and having much fewer spines ; there are only ves- 

 tiges of palea on the receptacle ; most part of the plant is clothed with sparse, 

 white hairs, wholly absent in the preceding. 



Bivision VI. — Ive^. (Decand.) 

 IvA ciliata. 



Hab. Arkansa. The old plant becomes extremely scabrous ; achenia turgid, oboval. 



Iva axillaris; leaves mostly alternate, somewhat carnose, linear-oblong, or 

 cuneate-oblong, obtuse, nearly smooth, one-nerved; capituli solitary, axillary, 

 nutant; involucrum of about five nearly separate, ovate sepals. Hook. Flor. 

 Bor. Am., Vol. II., p. 309, t. 106. 



Hab. On the borders of the Platte and Missouri. 



Iva *folialosa; lower leaves opposite, the upper alternate and smaller, all, as 

 well as the stem, more or less appressed pilose, three-nerved, lanceolate or ob- 

 long-lanceolate, subacute; flowers towards the summit of the stem, solitary, ax- 

 illary, nodding; involucrum campanulate, five-lobed. 



Hab. On the Rocky Mountain plains. /. axillaris, /3., Hook. Flor. Bor. Am., Vol. H., p. 309. 

 Probably Pursh's description is made up of both these species, though on the Missouri I saw only 

 the preceding, of which a specimen was communicated to the Lambertian Herbariuni. The pre^ 

 sent plant has a very different leaf and involuqrum, and often presents, as it were, a leafy spike^ 

 as mentioned by Hooker. 



Iva angustifolia. 



Hab. Arkansa. Capitulum minute, about four-flowered, three masculine, one feminine. Flow* 

 ers in a paniculated, leafy spike. 



Iva * microcephala; slender and virgately branched, very smooth ; leaves nar^ 

 row linear, almost filiform, entire and fleshy; capituli axillary, very small; se- 

 pals about five, distinct; florets about six, three of them female. 



Hab. In Florida. (Dr. Baldwin.) A remarkable species for the minuteness of its flowers and 

 leaves, the latter about half an inch long, half a line wide. The capitulum not much larger than, 

 an ordinary pin's head. 



^ I. *PlCROTUS. 



Flowers dioicous, one plant producing masculine flow^ers only with minute ru- 

 diments of fruit, the other with monoecious capituli, the radial florets with- 

 out corolla, the stigmas exserted, slender and filiform. Receptacle naked. 



