52 



ILLUSTRATIONS OF 



Cacabtis 



ing placentse. It has a prostrate habit, is about a foot long, its 

 radical leaves are 4 in dies in length, 3 inches broad, upon a pe- 

 tiole If to 2 inches : the cauhne leaves are 1^ inch long, 1 inch 



2 ^"^" ^""O) 



broad, on a petiole of 3 lines ; the peduncles are 11 inch, the 

 calyx 8 lines long, swollen in the middle, 4 lines in diameter, and 

 10-ner\'cd : the corolla is nearly 2 inches long, 1| inch diameter 

 across the mouth, which is obsoletely S-lobed. In all the other 

 species of Nolana mentioned in the work above referred to, the 

 calyx is described as being deeply 5-cleft, with the divisions 

 sagittate or cordate at the base, as in our well-known garden 



Sorema prostrata I but in the plant under consideration 



calyx 



agrees 



Thinogeton. 



This interesting genus was founded by Mr. Bentham upon one 

 of the plants collected on the coast of the Pacific, near Guayaquil, 

 during the voyage of the ' Sulphur / it is identical with Didno- 



it is identical with Dictijo- 

 vuiyx, proposea Dy jJr. Hooker tor a plant obtained by Mr. Dar- 

 win in one of the islands of the Gallapagos group. In many 

 respects its characters approach so closely upon Cacahus, that 

 some might feel disposed to consider them as congeneric; its 

 habit, however, is not so herbaceous, its stems are more strag- 

 ghng, terete, and though fistulose, are more woody ; the petiole 

 is rounder, thicker, and grows to an unusual length (three or 

 four times that of the blade) after the full growth of the leaf ; 

 the corolla is less campanular, more infundibuliform, and after 

 the impregnation of the ovarium, coils up spirally as in Convol- 

 vulus, and remains attached to the calyx until the fruit is ma- 

 tured; the stamens are more unequal and shorter, the filaments 

 less slender and more arched at their origin than in Cacabus; the 

 epigynous gland crowning the ovarium is much larger, more than 

 hemispherical, being gradually lost in the texture of the more 

 slender basal portion, while in Cacabus it is distinct, prominent, 

 and much smaller, rising on the summit of the germen, like a 

 small bulbular expansion of the style. A still more marked dif- 

 ference is seen in the calyx, which in the florescent state in Thi- 

 nogeton, is of much smaller diameter, quite tubular and invests 

 the contracted base of the corolla; it is of thicker texture, and 

 marked by ten prominent fleshy ribs, tapering gradually into the 

 peduncle : m Cacabus, on the contrary, the calyx is at least three 

 times the diameter of the base of the corolla, is more or less 

 globular, of extremely thin and transparent texture, venously re- 

 ticulated, phcated and deeply 5-angular, the angles being saccate 

 at base ; the peduncle in Thinogeton, after the impregnation of 



