326 PLANTS NOYJE THUKBERIAN^. 



exceeding the leaves. Pedicels and the orbicular sepals glabrous. Corolla about 4 

 lines long. Anthers subcordate. Unripe fruit 7 or 8 lines in diameter, yellowish. — 

 This is perhaps the Mexican plant figured in Mo^ino and Sesse's collection of draw- 

 ings, and doubtfully referred by De Candolle to /. ruscifolia ; but it does not belong 

 to that species. 



The remaining portions of Mr. Thurber's collection are rich in undescribed plants ; 

 but the greater part of these also occur in Wright's, Bigelow's, and Parry's collec- 

 tions. Two plants, however, found by Mr. Thurber alone, deserve particular notice ; — 

 one, a remarkable new genus of Eriogoneag, Centrostegia, found on the eastern borders 

 of California, the characters of which have been contributed to the forthcoming 

 volume of De CandoUe's Prodromus ; — the other, the new parasitic flower mentioned 

 by Mr. Thurber (supra, p. 315), as growing on the branches of a shrubby Dalea. 

 An account of it is subjoined. 



PiLosTYLES Thurberi (sp. uov.) : bracteis sepalisque rotundis margine nudis ; ovario 

 semisupero ; stigmate disciform! sessili medio subumbonato. — On a small mountain, 

 near the Gila River ; June, 1850 ; parasitic on the branches of Dalea Emoryi. 



To the four plants already known of the Apodanthece, a group appended to the 

 Rafflesiacece, Mr. Thurber has made an interesting addition in the present species. 

 These plants are simply single flowers, surrounded by a few bracts, parasitic and sessile 

 on the stems of various Dicotyledonous plants, mostly of Leguminosffi. While the 

 Rafflesias are extremely large, — the flower of R. Arnoldi, as is well known, measuriuo' 

 three feet in diameter, — the largest of the Apodanthese is only three lines in breadth 

 or length, and most of them, like the present species, of barely half that size. The 

 tribe, so far as known, is confined to America ; the original species of Pilostules, Guill. 

 (Frostia, Bertero, in Endl.) inhabiting Chili, and the two others being from Brazil, 

 while the single Apodanthes, Poit. was found in French Guiana. The present discov- 

 ery extends the range of the tribe into the temperate region of North America. The 

 late Mr. Gardner, who published (in Hooker's Icones Plantarum, t. 144 and t. 155) the 

 two Brazilian species, confidently referred them all to the older genus Apodanthes and 

 perhaps with sufficient reason. But Mr. Brown, in his conspectus of the RafiiesiaceEe 

 appended to his second memoir on Rafflesia, &c. (in Trans. Linn. Soc. 19, part 3) after 

 having examined original specimens of Apodanthes Casearice, preserved in spirits has 

 retained the two genera ; Apodanthes having a more manifest calyx and corolla the 



