Tas. 6122. 
PENTSTEMON uomiuis. 
Native of the Rocky Mountains. 
Nat. Ord, ScropHULARINEZ.—Tribe CHELONES. 
Genus Pentstemon, L’Her. ; (Benth. in DC. Prodr., vol. x. p. 320). 
Pentstemon humilis; glaberrimus, foliis radicalibus anguste lineari-lanceolatis 
ellipticis v. elliptico-spathulatis petiolatis integerrimis v. obscure crenatis 
acuminatis caulinis oblongis linearibusve, floribus racemosis breviter 
gracile pedicellatis, calycis lobis recurvis lanceolatis ciliatis, corolla 
semi-pollicari, tubo lente curvo modice inflato, limbo ceruleo 2-labiato, 
labii superioris lobis breviter oblongis inferioris late obovatis obtusis, 
-  filamentis glabris, antheranum loculis divaricatis, stylo piloso. 
Pentsremon humilis, Nutt. in Herb. Acad. Philad. ex A. Gray in Proc. 
Amer. Acad. Arts and Sc., October, 1862, p. 69; S. Watson Bot. 40th 
Parallel, pp. 220 and 454. 
The charming little plant here figured differs very much in 
stature and foliage from the indigenous specimens preserved 
in the Kew Herbarium, which are eight inches to a foot high, 
more robust, and have elliptic-ovate radical leaves, oblong- 
spathulate cauline ones, and flowers two-thirds of an inch long. 
All these, however, are differences of degree only, and I quite 
expect that older specimens of the cultivated plant will 
assume the stature and probably the foliage of the native 
ones. Add to these points the known variability of the 
species of Pentstemon, and that there is no other species to 
which the present bears any resemblance (except the foliage 
to the otherwise very different P. Hallit), and no doubt is 
left in my mind as to the identification of this with P. Aumi/vs. 
Pentstemon humilis was one of the indefatigable Nuttall’s 
discoveries in the Rocky mountains, and it has since been 
gathered by the naturalists attached to various American and 
English Government-exploring expeditions, amongst others, 
by Dr. Lyall, of the Oregon Boundary Commission, who 
collected it at 7000 feet above the sea, between Fort Colville 
and the Rocky mountains, in 1867. The plant here repre- 
SEPTEMBER, 1874, 
