Buddleja utahensis is a species of Buddleja endemic to the southwestern United States (northwest Arizona, eastern California, southern Nevada, and southwestern Utah), where it is known by the common names Utah butterfly bush and Panamint butterfly bush. Named and described by Coville in 1892, the shrub favours limestone outcrops at elevations of 700–2000 m, where it is often found in association with Joshua trees.
Buddleja utahensis is a compact, dwarf dioecious shrub reaching 0.3–1.0 m in height. The bark is rimose and greyish, while the plant structure is characterized by persistent naked twigs. The younger branches are terete, bearing subsessile linear to oblong leaves 1.5–3.5 cm long by 0.3–0.5 cm wide, rounded at the apex and attenuate at the base. Both surfaces of the leaves are densely short tomentose, bestowing a silver-grey appearance. The inflorescences are 4–12 cm long, with 3–7 pairs of heads forming verticels, subtended by leafy bracts. The verticels are 0.5–1.13 cm in diameter, each comprising 15–30 pale yellow flowers, the corollas 4–5 mm long. Capsules are up to 2.5 mm long, with numerous globose seeds up to 0.4 mm in diam.
- Buddleja utahensis was first described and published in Proceedings of the Biological Society of Washington 7:69. 1892. "Buddleja utahensis". Germplasm Resources Information Network (GRIN). Agricultural Research Service (ARS), United States Department of Agriculture (USDA). Retrieved January 22, 2012.
- Norman, E. M. (2000). Buddlejaceae. Flora Neotropica 81, pp 116–117. New York Botanical Garden, USA. ISSN 0071-5794
- Stuart, D. (2006). Buddlejas. Plant Collector Guide. Timber Press, Oregon, USA. ISBN 978-0-88192-688-0
- Norman, E.M. 1992. Buddlejaceae, Butterfly Bush Family. Journal of the Arizona-Nevada Academy of Science 26:5-6.
- Calflora Database: Buddleja utahensis (Panamint butterfly bush, Summer lilac, Utah butterflybush)
- Jepson eFlora (JM2) treatment of Buddleja utahensis[permanent dead link]
- UC Photos gallery — Buddleja utahensis
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