ADDISONIA 53 
(Plate 187) 
PENSTEMON SECUNDIFLORUS 
Lavender-pink Beard-tongue 
Native of the east slope of the central Rocky Mountains 
Family SCROPHULARIACEAE Ficwort Family 
Penstemon secundiflorus Benth. in DC. Prodr. 10: 325. 1846. 
This beautiful plant is a fit species with which to introduce the 
forms of Penstemon of the great home-land of the genus, the high- 
lands of western temperate North America. As are its congeners 
previously shown, P. secundiflorus is luxuriant of bloom and its 
flower-form alone would arouse our interest. Peculiarly its own is 
the unusual flower-color, a shade of lavender-pink with a suggestion 
of violet. 
No species better illustrates the appropriateness of the common 
name ‘beard-tongue.’ The genus Penstemon is distinguished by 
the presence within the corolla of a rudimentary or abortive stamen, 
of which the anther in the course of evolution has become wholly 
lost, while the well-developed filament lies like a ‘tongue’ along 
the lower side of the corolla throat. In our species this tongue is 
much enlarged, and on its upper side bears a dense beard of orange- 
golden hairs—a ‘bearded tongue’ conspicuous against the lavender 
ground-color of the flower. 
Penstemon secundiflorus is one of a group of closely related species, 
all distinguished by such a hairy tongue. They occur on the high 
plains, plateaus, and mountain foot-hills of the west, and the dis- 
tribution of each is surprisingly precise. Our species I have seen 
in abundance on loose granitic slopes at different points in the 
eastern foot-hills of Colorado, yet its entire range follows this 
narrow belt of land from southeastern Wyoming to northeastern 
New Mexico. Some species of this genus are known from but a 
single park-like valley or a single mountain-range or isolated peak,— 
when we can read the lesson of such dispersal, what information 
such plants will give of the evolution of climate and land on our 
continent! 
The lavender-pink beard-tongue is a quite smooth glaucous 
herbaceous plant, from a short rootstock sending up several stems, 
each terminating in a narrow panicle of lavender-pink flowers. 
The stems are erect, and nine to eighteen inches tall. The leaves 
of the winter rosette, persisting at the base of the stem until the 
