Penstemon mucronatus N.H.Holmgren

Authority

Pavlik, Bruce M. & Barbour, Michael G. 1988. Demographic monitoring of endemic sand dune plants, Eureka Valley, California. Biol. Conserv. 46: 217-242.

Family

Scrophulariaceae

Scientific Name

Penstemon mucronatus N.H.Holmgren

Type

TYPE: UNITED STATES. UTAH. Daggett Co.: Utah Highway 44, 6.5 km (4 mi) airline distance S of Manila, ca 0.8 km (0.5 mi) N of Sheep Creek crossing, T4N, R20E, S6, 1980 m (6500 ft) elevation, sandy slopes, 25 May 1978, N. Holmgren, P. Holmgren & R. Barneby 8747 (HOLOTYPE: NY; ISOTYPES: BRY, UT, UTC, and others to be distributed).

Description

Latin Diagnosis - Foliis integerrimis glabris glaucis sect. Coeruleis Pennell pertinens, foliis caulinis late ovatis apice acuminatis staminodioque lato P. pachyphyllo A. Gray ex Rydberg similis, sed staminodii pilis abbreviatis 0.3-0.8 (1) (nec 1-2) mm longis diversa.

Species Description - Short-lived perennial herb; stems erect or ascending, 1-2.5 (4) dm tall, single to few arising from a thick crown or short-branched caudex; herbage glabrous and glaucous; leaves entire, fleshy, the basal and lower cauline 3-6 (10) cm long, (10) 13-24 cm broad, oblanceolate, rounded or obtuse to acute, the upper cauline leaves (1) 2-3 cm long, 8-20 (30) mm broad, broadly ovate, mucronate; thyrse not secund, of 6-8 distinct verticillasters, the cymes several-flowered, glabrous; sepals (3.5) 5-6.5 mm long, broadly lanceolate, acute to acuminate, glabrous, becoming ribbed with age, the margins broadly scarious, entire to slightly erose; corolla 13- 17 (20) mm long, tubular-salverform, the tube 7-9 (10) mm long, the throat not very deep and 4.5-5.5 (7) mm broad (in pressed specimens), only slightly bilabiate, the lobes of the upper lip smaller than the lower, rounded, spreading, the lobes blue, the throat violet with dark reddish purple guidelines inside and onto the lobes, wholly glabrous except for the sparsely bearded palate; staminode reaching the orifice, distally expanded, 0.8-1.4 mm broad, and uncinate, bearded on the ridges with relatively short, brownish yellow to gollden-yellow hairs, the hairs 0.3-0.8 (1.0) mm long; fertile stamens included, the anther-sacs 0.7-1.0 (1.1) mm long (after dehiscence), dehiscing the full length, becoming opposite but tiot explanate, blackish on back, glabrous except for the papillate-toothed sutures; cap- sule ca 8-10 mm long.

Discussion

(Fig. 10)

Dry juniper and pinyon-juniper woodlands in sandy and gravelly soils, 1500- 2400 m (5000-8000 ft) elevation. Eastern end of the Uinta Mountains and low hills of the East Tavaputs Plateau of northeastern Utah, northwestern Colorado and adjacent Wyoming (Fig. 12). May-June.

The ovate to orbicular, mucronate-tipped leaves of P. mucronatus resemble those of P. pachyphyllus A. Gray ex Rydb., which lies to the west and south in north eastern Utah, and P. cyathophorus Rydb. from further east in north-central Colorado and adjacent Wyoming. The staminode of P. mucronatus is broad as in P. pachyphyllus but the bearding is of short, straight hairs 0.3-0.8 (1.0) mm in length rather than of long, densely tangled hairs of 1.0-2.0 mm length as in the latter. Penstemon cyathophorus differs from both these species by its exserted stamens and parallel anther-sacs. Also included in this alliance are P. osterhoutii Pennell and P. harringtonii Penland (see Penland, 1958).