330 CONTRIBUTIONS FROM THE NATIONAL HERBARIUM. 
Sterile filament relatively slender, scarcely or not lobed at the apex, 
bearded near the apex with yellow hairs; corolla 23 to 30 (-33) mm. 
long, usually decidedly pubescent within; sepals with an acuminate 
tip nearly equaling or exceeding the body; stem glabrous or puberu- 
CS 28. P. alpinus. 
Sterile filament relatively stout, frequently or mostly bilobate at the apex, 
glabrous (rarely with a few hairs at apex); corolla 30 to 40 mm. long, 
slightly pubescent or glabrous within; sepals with an acuminate tip 
shorter than the body; stem puberulent.......... 29. P. brandegei. 
Corolla 15 to 25 (-30) mm. long, the throat inflated anteriorly and not narrowed 
to the orifice, the anterior lobes spreading and glabrous at the base within; 
sepals minutely and usually obscurely glandular-puberulent externally. 
Corolla widening from a narrow basal tube; sepals ovate, with acuminate tip; 
plants 30 to 100 cm. tall. 
Corolla 15 to 22 mm. long, the posterior lobes united less than one-half their 
length; sepals with a long acuminate tip........ 30. P. saxosorum, 
Corolla (20-) 22 to 30 mm. long, the posterior lobes united over one-half 
their length; sepals with a short acuminate tip....31. P. subglaber. 
Corolla gradually widening from a broad basal tube; sepals broadly ovate, 
acute; plants 10 to 20 cm. tall................ 32. P. uintahensis. 
Anther sacs opening partially. 
Corolla 27 to 30 mm. long, the throat slightly narrowed to the orifice; sepals 
broadly ovate to orbicular, with broad scarious denticulate margin and 
short acuminate tip; thyrsus strongly secund; stem leaves lanceolate, 
narrowed to slightly rounded at the base............ 33. P. cyaneus. 
Corolla 20 to 30 mm. long, the throat not narrowed to the orifice; sepals lanceo- 
late to ovate, with no or moderate scarious margin, acuminate-attenuate; 
thyrsus not strongly secund; stem leaves with a broader rounded base. 
Corolla 20 to 25 mm. long; sepals attenuate-tipped, not or scarcely scar‘ous- 
margined. 
Stem leaves ovate, the largest 2 to 6 em. wide; stem glabrous throughout 
or puberulent only near the base; capsules 9 to 12 mm. long. 
34, P. cyananthus. 
Stem leaves lanceolate, the largest mostly 1 to 1.5 cm. wide; stem more 
puberulent, frequently so nearly throughout; capsules 8 to 10 mm. 
long..-..----.....2222222 2. 2c 34a. P. cyananthus subglaber. 
Corolla 25 to 30 mm. long; sepals shorter-tipped, decidedly scarious-margined; 
stem glabrous or puberulent........ 34b. P. cyananthus longiflorus. 
Anther sacs lanate with flexuous white hairs. 
Corolla deep blue, the throat obviously exceeding the basal tube; anther sacs 
less densely lanate; sterile filament more or less bearded (rarely glabrous 
in P. strictus); thyrsus strict, secund; pedicels relatively short; herbage 
brighter green, rarely glaucous. 
Anther sacs lanate-pubescent with slender hairs, these shorter than or about 
equaling the width of the sac. 
Anther sacs opening partially; pedicels and sepals somewhat glandular- 
puberulent. 
Leaves lanceolate, the cauline ones narrowly so, mostly acuminate, the 
largest 6 to 10 cm. long; sepals with broad scarious margin, acuminate 
to an attentuate tip; corolla 20 to 30 mm. long.! 
1 For description of a related new species, Penstemon mensarum, omitted in the 
key, see p. 380. 
