376 DESCRIPTIONS OF NEW SPECIES '-''^ 



*MACROCARPHUS. 



Hymenopappus, but with the leaves of the involucrum linear, numerous^ 

 (fifteen to twenty,) equal, in nearly a single series, and almost without mem- 

 branaceous margins. Receptacle naked. Florets tubular, the shortly five- 

 cleft border pubescent; the outer series somewhat ringent, but not spread- 

 ing. Branches of the style hirsute, filiform, thicker towards the extremity. 

 Achenium linear, conic, subcylindric, villous, attenuated below; with a 

 chaffy, nerveless pappus of about ten to twelve unequal, lacerated, oblong, 

 obtuse leaflets more than half its length; the pappus of the outer florets 

 shorter. — Biennial herbs of the north-west coast of America, and the Rocky 

 Mountains, with tomentose, bipinnatifid, alternate leaves. Stems dichoto- 

 mous, corymbose. Capitulum many-flowered, the florets rosaceous, or nearly 

 white, with the tube of anthers exserted, their cusps linear and acute, the 

 base naked. — Intermediate between Chsenactis and Hymenopappus; differ- 

 ing from the former in its nearly equal florets, filiform, and not subulate 

 stigma, nearly terete achenium, and a pappus of many long, obtuse leaflets; 

 from the latter in the narrow-leaved involucrum, long leaves of the pappus, 

 and the form of the florets, which are merely tubular, not campanulate. — 

 (Named in allusion to the great length of the pappus.) 



Macrocarphus AcliillecBfolms; canescently tomentose; branches corymbose, 

 leaves bipinnatifid, lobes short, oblong-obtuse; sepals canescently tomentose, 

 about twenty; chaff" of the pappus nearly the length of the elongated, villous 

 achenium. Chcenactis Achillecefolia; Hook, and Arn. Bot. Beech., 1. c. 



Hab. In the Rocky Mountain range, on Ham's Fork of the Colorado; common. Flowering in 

 July and August. Capitulum large, the florets pale rose-red. Robust, biennial, about four to six 

 inches high ; the leaflets and lobes crowded, as in Milfoil. 



Macrocarphus Douglasii; deciduously and slenderly tomentose; stem branch- 

 ing, corymbose; leaves pinnatifid, lobes entire or subdivided, oblong, obtuse; 

 sepals glandularly and minutely pubescent; radial achenium glandular ly sca- 

 brous, slightly pubescent, with a nearly equal pappus about half its length. 



