PLANTS COLLECTED BY DR. GAMBEL. 165 



an inch long, about a line wide, as strongly revolute on the margin as the leaves of 

 Kosemary. Flowers very numerous and showy, whitish, with red central lines ; 

 perianth pilose at the base ; some of the rays of the umbel nearly sessile. 

 Hab. Near Santa Barbara, Upper California. 



^. FOLioLosuM. Leaves more acute, with the petiole, young branches and the perianth, externally near 

 the base, pilosely pubescent. 



Hab. With the above. 



E. *vERTiciLLATUM. Biennial ; stem dichotomously branching, the offsets all subtended by verticels of 

 sessile, lanceolate, very acute leaves, in 3's ; radical leaves oblong, as well as the stems and branches 

 whiteiy tomentose, attenuated below into long petioles ; flowers wholly unknown. 



E. elongatum. (Benth.)? 



We have not seen the plant in flower, but the remarkable characters, somewhat 

 resembling those of E. tomentosum, and unlike any other species, perhaps justifies 

 our giving it a passing notice. 



Hab. Near St. Diego, Upper California. 



E. *NUTTALLii. (Gambel.) Densely ctespitose, with a woody, multifid, short caudex; leaves roundish, ovate or 

 elliptic, on short petioles, not exserted from the ca>spitose mass, whiteiy tomentose on both sides, as well 

 as the scape and involucrum ; capitulum solitary, rather small ; invohicrum cylindric, with obscure teeth, 

 cluster of involucres eight or ten, sessile ; flowers small, purple ; segments of the perianth oblong, not 

 very unequal. 



E. tenellum. Nutt. (Non. Torrey.) Proceed. Acad. Nat. Sci., Feb. 1848. 



Allied to E. ovalifolium, which it resembles at first glance, but with shorter leaves 

 and elongated scapes, the flowers deep brown-purple, and scarcely one-third the size 

 of that species. The capitulum in E. ovalifolium, like the present, is made up of 

 several sessile involucres, which are sometimes nearly smooth, the perianth also is 

 very unequal, three of the outer segments being nearly roand-oval, while the inner 

 are oblong. 



Hab. In the Rocky Mountains, on the western slope. 



The character of the genus Eriogonum, of which there are so many species, 

 perhaps deserves some additional consideration. The genus, as founded on E. 

 tomentosum of Michaux, possesses yet some peculiarities not common to the rest of 

 the genus ; among the rest of its characters I may remark, that in place of the interior 

 segments of the perianth being smaller, it is the reverse ; the perianth increases in 

 size with the perfecting of the fruit, and as in Rumex, the three inner segments are 

 larger and erect, the three outer reflected ; the next discrepancy in the character, as 

 given by authors, is in the condition of _ the embryo, which is placed in the centre or 

 axis of the seed, and is not as described excentric. 



In E. longifoUum, besides a remarkable difference in habit, the perianth is wholly 

 herbaceous, very lanuginous, and the segments all so very equal, as to appear, at 



