PLANTS NOV^ THURBERIAN^. 309 



der. Leaves thin ; their divisions 2 to 4 inches long, 6 to 12 lines wide towards the 

 base ; the ribs dotted underneath (like the branchlets, calyx, corolla, &c.), that of the 

 middle division usually bearing a linear excavated gland near the base : the uppermost 

 leaves often either unequally two-parted or entire, and ovate-lanceolate. Peduncles 

 about an inch long. Leaflets of the involucel narrowly lanceolate, entire, 3 to 5 lines 

 long, nearly twice the length of the cup-shaped and truncate entire calyx. Corolla of 

 five spreading, dilated-obovate petals, which are convolute in aestivation, an inch in 

 length ; their claws woolly-pubescent at the margin, united at the base by means of 

 the stamineal column. The latter is considerably shorter than the petals, and its upper 

 half is antheriferous quite to the apex, which is divided into five subulate sterile fila- 

 ments. Style longer than the androecium ; the exserted part gradually thickened up- 

 wards, and triangular, the salient angles stigmatose for nearly their whole length ; the 

 apex undivided. Ovary globose ; the three cells at first vertically divided in the mid- 

 dle by a nearly complete, but thin and delicate, spurious partition, projecting from the 

 back of each cell, which, however, as the ovary enlarges after anthesis, is soon broken 

 up into long and delicate horizontal shreds or hairs, that persist even in the ripe pod, 

 stretching from the dorsal suture almost to the axis, between the two rows of seeds. 

 Ovules ascending, nearly anatropous, biserial. Capsule ovoid, half an inch long, ob- 

 tuse and pointless, or nearly so, the base subtended by the persistent disc-shaped calyx 

 and the involucel. Seeds 2 to 2^ lines long, sparingly and minutely woolly. Albu- 

 men none, or a mere pellicle lining the membranaceous tegmen. Cotyledons large and 

 broad, incumbent on the radicle, transversely contortuplicate, and also longitudinally 

 plicate and folded around the radicle. 



This genus, it will at once be perceived from the characters here assigned to it, be- 

 longs to the tribe Hibiscece, and is most nearly related to Thespesia, having the same 

 calyx, involucel, androecium, &c. It is well distinguished, however, by its trimerous 

 gyncecium, and its dehiscent (three-valved) capsule, with the false dissepiments reduced 

 to a mere fringe of delicate woolly hairs ; to which may be added the persistent involucel, 

 the more complicate embryo, apparently without any albumen, and the habit of the 

 plant. Founded as the genus is upon perhaps the most elegant plant of the valuable 

 collection of Mr. Thurber, who alone appears to have met with it, I have great satisfac- 

 tion in dedicating it to the discoverer, himself well known as a meritorious botanist, 

 long before he engaged in the service of the Mexican Boundary Commission ; — in the 

 course of which, besides fulfilling the proper duties of an arduous and responsible 

 office, he has been able largely to increase our knowledge of the botany of the whole 

 desert frontier. 



