22 | Muhlenbergia, Volume 4 
THE GENUS ROSENBERGIA 
By HOMER DOLLIVER HOUSE 
To the treatinent of the genus Cobaea by Brand, Pflanzen- 
reich IV. Fam. 250: 25-28. 1907, little need be added in the 
way of specific descriptions, except to call attention to the in- 
validity of the generic name Cobaea Cav., which is antedated 
by Cobaea Necker. Brand has apparently also transposed the 
species C. macrostoma and C. triflora, to judge from the descrip- 
tions and specimens cited, and has reduced C. ¢rzflora to a va- 
riety of the former. The type of Cobaea Cav. is C. scandens, 
while the type of Rosenbergia is R. gracilis. These two spe- 
cies represent groups of such divergence of characters that they 
might easily be regarded as separate genera were it not for a 
species (C. Aschersoniana) which is intermediate between the 
two groups. 
The genus Cobaea belongs to the tribe Cobaeeae of the 
Polemoniaceae, and the invalidity of the generic name Codaea 
Cav. suggests the proposal of a new tribal name Rosenberg- 
ieae. 
Of the eleven known species, eight occur in tropical North 
America, from Mexico to Panama. ‘The other three species are 
confined to tropical South America. C. scandens is common in 
cultivation. 
ROSENBERGIA Oersted, in Vidensk. Meddel. Kjoebenhavn. 
30. 1856. 
Cobaea Cav. Ic. 1: 11. pls. 76, 77.1791. Not Cobaea Neck. 
Elem. 1: 129. 1790. 
Twining leafy vines: carpels septicidal: sepals foliaceous or 
membranaceous: flowers solitary, large, axillary: leaves com- 
pound, the rachis terminating in a tendril. 
