PENNELL—SCROPHULARIACEAE OF THE ROCKY MOUNTAINS. 833 
Plants essentially glabrous; leaves filiform or nearly so, closely tufted on abbreviated 
basal branches arising from the shortened caudex; corolla throat less inflated. 
Corolla throat evidently inflated, 9 to 10 mm. long, evidently 2-lipped, the pos- 
terior lobes 4 to 7 mm. long, the lobes spreading to a breadth of 10 to 15 mm., 
‘‘white’; anther sacs ovate-lanceolate; sterile filament densely bearded 
C60) a) en 54. P. exilifolius. 
Corolla throat slightly inflated, 10 to 12 mm. long, sligntly 2-lipped, the posterior 
lobes 3 to 4 mm. long, the lobes spreading to a breadth of less than 11 mm., 
light red-violet; anther sacs linear-lanceolate; sterile filament slightly to 
moderately bearded dorsally..................-- teeeeeee 55. P. laricifolius. 
XII. AMBIGUI. 
Asingle species.........-....00. eee e cece e ec eee cee cece e eens 56. P. ambiguus. 
Asingle species....... 2.00.00 0 cece cece eee ee eee c eee e eee eeeeees 57. P. deustus. 
XIV. GRACILES. 
Corolla glabrous externally (rarely with a few glandless hairs distally). 
Sepals triangular, slightly scarious but nearly entire below, one-third to two-fifths 
the length of the capsule. Thyrsus of lax fascicles; flowers more distinctly 
pediceled...... ccc eee ee eee eee eect eee e cece eens 58. P. watsoni. 
Sepals long-acuminate to caudate-tipped, conspicuously scarious and more or less 
erose-lacerate below, at least one-half the length of the capsule. 
Corolla 8 to 10 mm. long, the throat 2 mm. wide. 
Calyx glabrous externally. 
Sepals with long caudate tip and with relatively slightly toothed scarious 
MALGiN. 2 eee eee eee eee eee eee eee eee eeeeesee---+ 5G, P, procerus, 
Sepals with short caudate tip and with relatively more lacerate scarious 
MAMGIN.. .. eee eee eee eee eee eee ee eee 59a. P. procerus aberrans. 
Calyx pubescent externally.............----.. 59b. P. procerus pulvereus. 
Corolla 10 to 18 mm. long, the throat 2.5 to 4 mm. wide. 
Corolla 10 to 14 mm. long, densely pubescent within, deep violet-blue; sepals 
with conspicuously broad, strongly lacerate margin below, and relatively 
shorter tip, always glabrous; thyrsus densely congested..60. P. rydbergii. 
Corolla 15 to 18 mm. long, slightly to moderately pubescent within, lighter 
violet-blue; sepals with narrower, less lacerate margin below, and rela- 
tively longer tip, pubescent or glabrous; thyrsus less densely congested. 
61. P. aggregatus. 
Corolla glandular-puberulent externally. 
Corolla pale to deep blue, the throat 1.8 to 4 mm. wide; capsule lance-ovate, 5 to 
7 mm. long; plants erect, 10 to 80 cm. tall; thyrsus of many several-flowered 
axillary clusters. 
Corolla deep or violet blue, slightly paler anteriorly, the throat less strongly 
ridged within anteriorly and not apparently inflated posteriorly, the posterior 
lobes abruptly spreading and but little exceeded by the anterior ones; plants 
ascending from creeping stems. 
Corolla 15 to 20 mm. long; stem puberulent in lines. Blades of basal leaves 
over 3 cm. long. 
Corolla 17 to 20 mm. long, deep blue, the throat slightly inflated; sepals 
3.5 to 7 mm. long, with broad and more or less lacerate scarious margin; 
stem leaves nearly always entire; thyrsus more crowded; plants paler 
STEEN. - 2... eee eee eee ee eee eee e eee ea ccceaae 62. P. pseudoprocerus. 
