PENNELL—SCROPHULARIACEAE OF THE ROCKY MOUNTAINS. 367 
Ipano: Fremont: Beaver Canyon, Shear 3033 (Y), 3053 (Y); Canyon Creek (U, Y); 
Island Park (F). 
60. Penstemon rydbergii A. Nels. 
Penstemon rydbergit A. Nels. Bull. Torrey Club 25: 281. 1898. ‘‘It was met with 
in abundance in an aspen grove in a draw in the Laramie Hills [Wyoming], July 1, 
1897. Type specimen collected at Green Top [Albany County], in Herb. Univer- 
sity of Wyoming, A. Nelson no. 3214.” Isotype seen in herbarium of Columbia 
University at the New York Botanical Garden. 
Penstemon erosus Rydb. Bull. Torrey Club 28: 28. 1901. ‘Colorado: Indian 
Creek Pass, 1900, F. K. Vreeland, 615 (type).” Type seen in herbarium of the New 
York Botanica] Garden. . 
Penstemon lacerellus Greene, Leaflets 1: 161. 1906. ‘‘At Sargents’, southern 
Colorado, 5 July, 1901, C. F. Baker, n. 352, as in U. S. Herb.” Type seen in U. S. 
National Herbarium. 
Penstemon latiusculus Greene, Leaflets 1: 161. 1906. “Stony ground along stream 
banks at Gunnison, Colo., 24 July, 1901, C. F. Baker, n. 588, as in U. S. Herb.” 
Type seen in U. S. National Herbarium. 
Intergrades with P. procerus; apparently nearest to P. procerus aberrans, from 
which, however, its larger flowers and more lacerate sepals distinguish it. 
Moist grassy flats or slopes, aspen thickets, at altitudes of (2,100) 2,200 to 3,000 
(3,300) meters; Submontane and Montane zones; flowering from late June to mid- 
August. Mountains, eastern Wyoming, southward on both continental slopes, 
through most of Colorado. 
Wromine: Albany: Antelope Basin (M, U, Y); Centennial, Nelson 8725, in part 
(M, U, Y); Chug Creek (M, U, Y); Green Top, Nelson 3214 (M, Y); Nashs Fork 
(Y); head of Pole Creek (Y); Sherman (F). Carbon: Hayden Forest, Eggle- 
ston 11242 (U). Johnson: Crazy Woman Creek, 7. A. Williams (U). Laramie: 
Horse Creek, E. Nelson 80 (Y). 
Conorapo: Chaffee: Salida, Clements 253 (Y). Clear Creek: Grays Peak (U); 
Mount McClellan, E. L. Greene (E). Delta: On Tongue Creek, Mesa Grande, 
Purpus 303 (F). Grand: Middle Park, W. A. Henry (M). Gilpin: Central 
City (Y); Eldora to Baltimore (Y); Tolland, Pennell 6371 (¥), 6377 (M, U, Y). 
Gunnison: Gunnison, Baker 588 (M, U, Y), Pennell 6288 (D, R, Y); Parlin (Y); 
Pitkin (Y); Sapinero (B). Huerfano: Indian Creek Pass, Vreeland 615. i 
mer: Mountains, Osterhout 57. Mineral: Wagon Wheel Gap, B. H. Smith (A, F). 
Montezuma: Chicken Creek, Baker, Earle & Tracy 658 (F, M, U, ¥). Ouray: 
Engineer Mountain, Purpus 706 (F). Park: Como, Crandall 4795 (Y); Saguache: 
Marshall Pass (U, Y); Sargents, Baker 352 (M, U, Y), Pennell 6293 (A, D, H, K, 
Y), 6301 (Y). Summit: Robinson, Shear 3329 (U, Y). 
Uran: Uinta: Youngs Springs, Goodding 1196 (F, M, U, Y). 
61. Penstemon aggregatus Pennell, sp. nov. 
Stems few or several, slightly decumbent at base, erect, 30 to 80 cm. tall, from a 
much-branched rootstock, puberulent in lines to glabrous above, pale green; leaves 
Pale green, obscurely veined, glabrous, those at the base of the stem much tufted, 
the blades lanceolate, acute (or the lowermost obtuse), entire, altogether 5 to 17 cm. 
long, narrowed into a petiole-like base one-half to two-thirds the length of blade, 
the stem leaves lanceolate or narrowly lanceolate, the upper ones slightly clasping, the 
largest 7 to 15 cm. long, 1 to3 cm. wide; thyrsus narrow, not secund, less than one-half 
the height of the plant, composed of 3 to 8 rather close fascicles, each consisting of 2 
axillary, closely erect branches, their pedicels shorter to much longer than the pedun- 
cle; sepals 5 to 7 cm. long, lanceolate-attenuate, acuminate, not veined, with white 
