1899] SOME ROCKY MOUNTAIN CHRYSOTHAMNI 371 
Nutt., to which it is allied on the one side, by its less glabrate condition, its 
narrower leaves, yellow stems, paniculate (not corymbose) inflorescence, and 
proportionately shorter style appendages. From C. sfeciosus Nutt., to which 
it must be compared on the other side, by its stout yellow (not whitish) 
branchlets, its longer less filiform leaves, glabrate involucral bracts, pubes- 
cent corolla tube, and more open-paniculate inflorescence. 
Under no. 2066 it has been distributed as C. Speciosus, from Cummins, 
August 10, 1896. Collected near the same locality (Wood’s Landing), 
August 9, 1897, no. 3477, the latter taken as the type number. Specimens 
from Gros Ventre river, August 23, 1894, no. 966, is a form with more virgate 
and glabrate branchlets. 
CuRYSOTHAMNUS PULCHERRIMUs fasciculatus, n. var.— size and 
habit of the species; the season’s branchlets short, numerous, 
forming a brush-like fascicle at the ends of the woody branches : 
leaves numerous, short (2-3), somewhat rigid, green or yel- 
lowish-green, with a thin tomentum: inflorescence similar to that 
of the Species but smaller, terminating the numerous branchlets. 
The fascicled branchlets and short rigid leaves suggest C. co/linus 
Greene, but the size, habit, inflorescence, and floral characters are those of 
C pulcherrimus. C. collinus, in its pubescent long acuminate bracts, is quite 
N contrast to this. 
First collected in 1894 on Boulder creek, August 26, no. 1120; in 1897 
at Creston, August 28, no. 4419 and distributed as C. sfeciosus. 
_ Curysornamnus FRIGIDUS Greene, 1. c.— What is typical of 
| this species is not quite clear (see note under var. concolor), but 
it seems plain that it was intended to include that superabundant 
but variable species of the high plains, popularly known as 
_“fabbit-brush.” It is illustrated by Dr. Greene’s specimens from 
famie, August 10, 1895; the writer’s nos. 2787, 5280, 5282, 
ay 
Curysornamnus FRIGIDUS concolor, n. var.— Yellowish-green 
| throughout except for the bright yellow flowers, 3-4°" high from 
. barely shrubby base, the numerous stems rather slenderly 
“itgate, terminating in a narrow thyrsus (sometimes peicete 
_“*tymbose): leaves linear, erect or irregularly spreading, eA 
6: t-2™ wide: bracts mostly acute, the outer with a light 
‘omentum like that of the stems and leaves, all with a thin, 
- atious-ciliate margin: corolla tube short-pubescent. 
