I. PLAXT.E FREIIOXTIXSM. 15 



surrounded, in a spiral manner, with usually about ten broad spreading winglikc 

 scales of a silvery color. The scales are thickened and indurated at the base. 

 The achenium is of a dark purple color, and is completely enclosed in the coria- 

 ceous body of the involucre. It is tipped with the long and persistent style, 

 which is much exserted through the tubular rostrum. 



The only specimens of this plant which I have ever seen, were collected by 

 Colonel Fremont, in the place above mentioned. Afterwards another species of 

 the same genus was discovered by Major Emory on the Gila River, and is briefly 

 noticed in the Botanical Appendix to his Report, under the name of II. monon^ ra, 

 Torr. Sf Gray. The same plant has since been found in California by Colonel 

 Fremont; at Ojito, in New Mexico, by the late Dr. Gregg; and in Texas by Mr. 

 Charles Wright. It is described by Dr. Gray, in his Plantse Fendleriana-, p. 79. 

 In my specimens of H. monogyra from the Gila, the scales in several of the fruc- 

 tiferous involucra are broad, and not contracted at the base. The sterile heads 

 are rather smaller than in H. Salsola, and the chaff is spatulate. 



This genus is very nearly allied to Franseria, but differs in the remarkable wing- 

 like scales of the fructiferous involucre, as well as in habit. Perhaps the fol- 

 lowing interesting plant, found by Colonel Fremont on his return from California 

 in 1849, may unite Franseria and Hymenoclea. 



FRANSERIA. 



Franseria deltoidea (sp. nov.): caule erecto suffruticoso glabriusculo ; foliis 

 deltoideis indivisis eroso-denticulatis subtus dealbatis ; involucris fcemineis subglo- 

 bosis bilocellatis bifloris ; squamis lanceolatis breviter spinescentibus, margine 

 submembranaceis, exterioribus latioribus. 



Hab.— On the Gila River, Southern California : collected by Colonel Fremont, in 

 returning from his fourth journey. Found also by Dr. C. C. Parry, on the same river. 



Stem apparently suffrutescent, with slender angular branches, which are clothed 

 with a deciduous pubescence. The leaves are deltoid, or deltoid-ovate, scarcely 

 an inch long, obtuse or subcordate at the base, irregularly erose-toothed, 

 tomentose on both sides, almost white underneath, except the reticulated veins. 

 The heads are not larger than a small pea, and are disposed in racemose spikes, 

 which are about two inches long. The sterile ones are pedicellate, with the . 

 involucre pubescent, 5-6-toothed, and about fifteen-flowered. Corolla of the 

 sterile flowers tubular-infundibuliform and glabrous ; the bracteole or chaff at its 

 base broadly ligulate. The fertile involucre is sessile ; the base surrounded with 

 imbricated broadly ovate membranaceous mucronate bracts, which are crenulate 

 on the margin ; scales numerous, membranaceous on the margin, terminating in a 

 sharp stout scabrous spine, which is often a little curved or uncinate at the tip. 

 Styles filiform and obtuse. 



* Journ. of the Acad. Sc. Philad. n. ser. vol. 1. p. 172. 



