16 PLANTS FRiMOXTIANJE. I. 



A remarkable species, partaking of the character both of Hymenoclea and 

 Franscria. There is a transition from the broad and somewhat membranaceous 

 bracts at the base of the fertile head, to the lower scales of the involucre, and 

 from these, with a broad base and spiny top, to the narrow prickles that occur in 

 many species of Franseria. 



A genuine and apparently new species of the latter genus occurs among the 

 plants collected in California by Colonel Fremont. It belongs to the section 

 Centrolsena of De Candolle, and may be thus characterized. 



Franseria albicaulis : frutescens, incano-pubescens ; fohis bipinnatifidis, 

 laciniis oblongis vel lineari-oblongis obtusis integris vel pauci-dentatis ; capitulis 

 dense spicato-racemosis ; involucro masculo 8-dentato, fructifero biloculari acu- 

 leis lanceolato-subulatis rigidis incurvis armato. 



Hab. — Southern California, probably on the Gila : Colonel Fremont. It was 

 also found, without flower or fruit, by Major Emory, on the sandhills of the Gila ; 

 and is the plant referred to in my botanical appendix to his Report, as an 

 apparently new species of Ambrosia. 



A shrub with numerous branches, which are clothed with a short whitish 

 pubescence. The leaves are about an inch long, grayish pubescent on both sides, 

 and pinnately or bipinnately divided ; the narrow ultimate segments being from one 

 to three lines in length. The heads are about the size of a small pea, and are 

 disposed in close leafless spiked racemes. Some of the racemes are wholly 

 staminate ; others have fertile heads intermixed. Sterile heads on short pedicels, 

 with the involucre obtusely 7-8-toothed. The chaff is filiform and bearded. 

 Corolla five-toothed. The fructiferous involucres are globose, and thickly covered 

 with rather rigid, compressed. Curved prickles, which are slightly roughened, and 

 about as long as the scmidianieter of the involucre. 



This species is near F. dumosa Gray, described in my Botanical Appendix to 

 Fremont's Second Report; but it differs in the more divided leaves, and in the 

 rigid, nearly glabrous, curved, and larger scales of the involucre. 



AMPHIPAPPUS, Ton-. & Gray. 



Capitulum plerumque sexflorum, heterogamum ; nempe flore radii unico ligulato, 

 femineo, fertili, et floribus disci quinque, tubulosis, hermaphroditis, sed sterilibus. 

 Involucrum obovoideum, squamis septem ad novem, subsequalibus, concavis, 

 subcarinatis, appresso-imbricatis. Receptaculum angustum, subalveolatura. Ligula 

 brevis, obovata, discum vix superans : corolla disci e tubo gracili infundibuliformis, 

 limbo profunde quinquefido. Styli rami breves Linosyridis ; appendiculo ovato- 

 deltoideo superati. Achenium radii oblongum, compressum, villosum, pappo 



