BOTANY. 123 
Arnott under P. heterophyllus. The present single specimen resembles the var. «, in the narrow 
and marginless sepals, and in the smaller flowers; but the peduncles are principally three- 
flowered. Not improbably it belongs to an entirely different species, 
PENTSTEMON HETERANDRUM (n. sp.): glabrous; stem slender, virgate; leaves lanceolate or 
oblong-linear, obtuse, callose-serrulate, obtuse or subauriculate at the base; panicle spicate, 
interrupted ; cymes subsessile, several-flowered ; calyx puberulous, the segments ovate-lanceo- 
late ; corolla (nearly white) infundibuliform, slightly gibbous above, with 5 short subequal 
lobes, in estivation various ; stamens glabrous, straightish, of nearly equal length, all anther- 
iferous, or the fifth without an anther. Sierra Nevada, California; June 30. Flower white, 
with pink lines half an inch in length. Cauline leaves an inch long, and 3 lines wide; the 
floral ones successively reduced to small bracts. Anthers glabrous; the cells distinct, mod- 
erately diverging. Stigma minute and simple. Ovary, &c., apparently as in Pentstemon. 
Fruit not seen. Two peculiarities are to be noticed in this remarkable plant, either of which 
would have been sufficient to exclude it from Pentstemon, but both prove to be inconstant in 
the species. One of these relates to the stamens, which, in the flowers examined, were per- 
haps more frequently completely pentandrous than otherwise; the fifth (posterior) filament 
being similar to the others, and bearing either an exactly similar anther, or sometimes one 
with rather smaller cells, and with the filament or connective prolonged into a short and blunt 
apical appendage, as shown in figures 9 and 10. In some flowers, however, this anther was 
found to be reduced to a single and rather imperfect cell, and a bare rudiment of the second 
cell, as in fig. 11; in others again, (as in fig. 12 and fig. 6,) the fifth stamen is wholly desti- 
tute of any trace of anther, as in Pentstemon universally, with this exception, if such it be. 
It is also to be noted that the stamens of this plant are nearly equal in length, at least when 
all five are antheriferous, and that they are inserted into the very base of the corolla. The re- 
maining peculiarity relates to the estivation of the corolla; in which, although some of the 
flower-buds plainly have the two posterior lobes, or one of them, exterior to the others, in the 
manner of the Antirrhinidex generally, (this being, indeed, the only absolute character of that 
suborder), as shown in figures 3 and 4; yet, in quite as many instances we find the lateral 
lobes exterior.in the bud, and covering the two posterior as well as the anterior, (as is repre- 
sented in figure 2), in the manner of the Rhinanthidee: a new and striking instance of 
the instability of the modes of estivation of the corolla, and one not altogether unexpected, 
since Mr. H. T. Clark, a former pupil of Dr. Gray, and an acute and zealous naturalist, showed 
him several years ago that both modes occur in Mimulus ringens, M. moschatus, 
Mimutus tutevs, Linn. In the Sierra Nevada; June. 
CastTintesa Hisprpa, Benth. in Hook. Fl. Bor.—Amer. 2, p. 105. Cedar Mountains, south of 
Great Salt Lake; May. 
CastiLiesa Pattipa, Kunth. Foot of the Humboldt Mountains, on the eastern side; May. 
AUDIBERTIA INCANA, Benth, in Bot. Reg. t. 1469; and in DC. Prodr. 12, p. 359. On the 
Sierra Nevada; June 20. Flowers blue. 
MOoNARDELLA oporatissIMA, Benth. Lab. p. 332; and in DC. Prodr. 12, p. 190. . @uasrtus- 
CcULA; nearly glabrous; branches slender; leaves oblong-lanceolate, narrowed to a petiole at the 
base, rather acute; heads terminal; bracts ovate, (colored,) shorter than the calyx, rather 
acute ; teeth of the calyx ovate-lanceolate, acute, unarmed. Sierra Nevada; July 8. Differs 
from M. odoratissima in its larger and conspicuously petiolate leaves, and in the narrower 
acutish bracts, &c. Flowers rose-colored. 
Most of the species of this genus have the narrow lobes of the corolla sacculate at the apex; 
a character which seems to have escaped the notice of Mr. Bentham. 
MERTENSIA OBLONGIFOLIA, G. Don, Syst. Gard. 4, p. 372; DC. Prodr. 10, p.92. Pulmonaria 
oblongifolia, Nutt. in Journ. Acad. Phil. 7. p. 13. Pass in Humboldt Mountains; May 23. 
Flowers blue. This species was found also in various parts of Utah, by Colonel Fremont. 
