Penstemon humilis var. obtusifolius

Non-technical Description:Zion penstemon is a mat-forming perennial forb with numerous erect, pubescent, leafy stems 7-35 cm tall.  Leaves are usually minutely toothed and dark green.  Basal leaves are 1-9 cm long with oval blades and petioles. Upper stem leaves are sessile and narrower.  The glandular-pubescent inflorescence consists of 3-9 discrete whorls of flowers.  Flowers have violet or dark blue tubular corollas 8-19 mm long and a glandular green calyx 3-5 mm long.  Anther sacs are 0.4-0.8 mm long and open their entire length.  Fruits are capsules 4-8 mm long. Flowering occurs from April-June. (Cronquist et al. 1984, Fertig 2010, Welsh et al. 2008).

Similar Species: Rydberg’s penstemon (Penstemon rydbergii) has entire leaves and glabrous inflorescences. Rockville penstemon (P. pachyphyllus var. congestus) has waxy, bluish-green leaves and glabrous inflorescences.

 Habitat: Occurs in pinyon-juniper, oak, montane brush, and Ponderosa pine communities on Navajo Sandstone bedrock and shallow sandy soils at 1580-2450 m (5180-8040 ft) (Fertig 2010). 

References: Cronquist, A., A.H. Holmgren, N.H. Holmgren, J.L. Reveal, and P.K. Holmgren, eds. 1984. Volume 4, Subclass Asteridae (except Asteraceae).  Intermountain Flora, Vascular Plants of the Intermountain West, U.S.A. New York Botanical Garden, Bronx, NY. 573 pp. Fertig, W. 2010.  Rare plants of Zion National Park.  Moenave Botanical Consulting, Kanab, UT. 95 pp. Welsh, S.L., N.D. Atwood, S. Goodrich, and L.C. Higgins.  2008.  A Utah Flora, 2004-2008 summary monograph, fourth edition, revised.  Brigham Young University, Provo, UT.  1019 pp.

Author: Walter Fertig, Moenave Botanical Consulting, Kanab, UT. April 2017