66 
2. By transferring these species from Parosela or Dalea to 
Petalostemon, which would meet with perhaps as little favor, as 
the latter genus has always been known by its 5 stamens. 
3. By proposing a new genus to include these species, as Dalea 
is not an available name. I have chosen the last method. 
As nearly all the species differ from Psoralea Dalea L. (Dalea 
nigra Mart. & Gal.) in being perennials and closely resembling 
each other in habit, it seems better to select the type of the new 
genus from among these rather than to assign Psoralea Dalea L. 
as such. 
The type selected, Dalea albiflora A. Gray, and several of its 
closer relatives are found in Arizona, New Mexico, and northern 
Mexico. I therefore think it fitting to associate these plants 
with a student who has done much botanical work in this region 
and take pleasure in naming the genus in honor of Professor John 
James Thornber of the University of Arizona. 
Thornbera Rydberg, gen. nov. 
Perennial or annual herbs, related to Pefalostemon and Parosela. 
Flowers in usually dense spikes. Calyx campanulate, 10-ribbed, 
5-lobed. Petals all distinct; banner inserted on the hypanthium 
in the bottom of the calyx, with a cordate or ovate blade and a 
long claw; wings and keel-petals similar to each other, subsessile 
or short-clawed, inserted at the mouth of the staminal tube, the 
blades oval or obovate, slightly oblique but not lobed at the base. 
Stamens 10 or 9, monadelphous, the upper portion of the fila- 
ments free. Fruit indehiscent, 1-seeded. 
Type species, Thornbera albiflora (A. Gray) Rydberg. Dalea 
albiflora A. Gray, Pl. Wright. 2:38. 1853. 
P, A. RYDBERG 
