PENNELL—SCROPHULARIACEAE OF THE ROCKY MOUNTAINS. 825 
PENSTEMON [Mitchell] Schmidel.! 
KEY TO SECTIONS. 
Anther sacs opening from the distal apex, throughout or partially; seeds grayish 
brown or brown, deepening to blackish, minutely or obsoletely reticulate. 
Corolla scarlet, somewhat fleshy, the throat tubular. EtmieEra (Reichenb.) Benth. 
Corolla 25 to 30 mm. long, the posterior lobes 5 mm. long, united one-half their 
length, the anterior lobes scarcely spreading; anther sacs 2 mm. long, lanceo- 
late, minutely puberulent, slightly united at base; seeds 2.5 mm. long, less 
sharply angled; leaves at base of stem obovate, those on the stem ovate, the 
upper ones rounded at base, the opposite leaves completely clasping the 
stem; thyrsus strict, the peduncles and pedicels short. .I. Centhranthifolii. 
Corolla 30 to 35 mm. long, the posterior lobes 8 to 12 mm. long, united two-thirds 
to three-fourths their length, the anterior lobes decurved-reflexed; anther 
sacs 1.5 to 2 mm. long, triangular-ovate, scarcely puberulent, broadly united 
at base; seeds 2 to 2.2 mm. long, sharply angled; leaves at base of stem 
lanceolate-oblong, those on the stem linear to lanceolate, narrowed at base 
and slightly clasping, the opposite leaves not meeting; thyrsus lax, the 
peduncles and pedicels longer. ..........----------eeeeeeeees II. Barbati. 
Corolla dull red, blue, purplish blue, or white, membranous, the throat usually 
wider. : 
Anther sacs glabrous to lanate; seeds merely angled; corolla throat terete or 
anteriorly flattened and ridged within. Inflorescence thyrsoid, rarely 
seeming racemose; leaves thin to succulent, not coriaceous; plants her- 
baceous to suffrutescent at base. EuPENSTEMON Benth. 
Corolla throat rounded anteriorly; seeds brown, 1.5 to 5 mm. long; stems erect 
from base, not suffrutescent; plants probably biennial. 
Corolla glandular-puberulent within, white or red. 
Corolla red, the throat narrow; sterile filament glabrous; leaves entire; 
plants glabrous, glaucous..........-----------+--- III. Utahenses. 
Corolla white, the throat broad; sterile filament bearded; leaves fre- 
quently dentate; plants rough-puberulent, not glaucous...IV. Albidi. 
Corolla not glandular-puberulent within, blue or purplish blue (except in 
Spectabiles and Petiolatt). 
Leaves broadly linear to orbicular. 
Corolla throat nearly tubular, the posterior lobes united but slightly at 
base, the corolla scarcely 2-lipped. Plants cinereous-puberulent; 
corolla glabrous within.............-....--2+--- V. Fremontiani. 
Corolla throat evidently inflated anteriorly, the posterior lobes united 
at least one-fourth their length, the corolla evidently 2-lipped. 
Leaves relatively thin, not fleshy; plants scarcely or not glaucous 
(except in Spectabiles and Petiolati); sterile filament relatively 
slender, scarcely or but slightly enlarged distally; seeds 1.5 to 
3.5 mm. long, finely and closely reticulate; posterior corolla lobes 
more arched, usually but slightly spreading. 
Plants more or less densely puberulent or pubescent; corolla mostly 
purplish, the posterior lobes mostly less united, always for less 
than one-half their length; anther sacs always glabrous, the line 
of contact between the sacs relatively long. Sterile filament 
conspicuous, densely bearded with yellow or orange hairs; seeds 
more evidently reticulate. ........-.....-.+---- VI. Cristati. 
10. C. Schmidel, Icones Plantarum 2. 1762. Type, from description and pre- 
Linnean citation, Chelone pentstemon L. This would establish the orthography 
‘*Penstemon.”’ 
