338 PITTONIA. 
I at first, and in the herbarium, took this to be a probable 
form or variety of V. cuspidata; but since having grown the 
two side by side, I perceive abundant specific distinctions, 
the most obvious one, at all seasons and stages, is the deltoid 
leaf-outline of V. populifolia. It is in the Canadian Survey 
Herbarium under n. 18,752. 
A FascicLE or New LABIATÆ. 
HEDEOMA DIFFUSA. Low, suffrutescent, the numerous 
branches tufted on a branching woody caudex, from strongly 
decumbent to almost prostrate, 3 to 6 inches long, the herb- 
age from hoary-tomentulose in the northern and typical 
form to merely cinereus-pubescent in the more southerly 
specimens: lower leaves short-petiolate, the blade from 
orbicular to round-ovate, entire, scarcely 2 lines long, the 
upper and floral commonly ovate: flowers few in the axils: 
calyx small, only 14 or 2 lines long including the rather 
short and subequal teeth, the tube gibbous, hispidulous on 
the ribs: corolla very large for the plant, the tube little 
exserted, but limb ample, rich purple. 
Species as far as known confined to Arizona, where, in 
several forms, it ranges from north to south throughout the 
State; the type being a plant obtained near Flagstaff by 
H. H. Rusby, in 1883, and distributed under a manuscript 
name of mine which is not here taken up, not being appro- 
priate to the more southerly forms of what I take to be 
specifically the same. It was obtained again at Flagstaff, in 
1891, by Mr. D. T. McDougal. The less diffuse and less 
distinctly hoary plant was collected by myself, in the south- 
eastern part of Arizona, near Wall’s Ranch, 4 Sept., 1880. 
This appears to have been the earliest gathering. This 
same isin the U. S. Herbarium from Cedar Springs, by 
Toumey, 1892. The whole was referred, by Dr. Gray, as 
far as known in his day, to his rather confused H. thymoides. 
