The following Participating Institutions are custodians for this species in the CPC National Collection:
The Arboretum at Flagstaff
Cincinnati Zoo & Botanical Garden
The conservation of Purshia subintegra is fully sponsored.
Joyce Maschinski, Ph.D. contributed to this Plant Profile.
Arizona cliffrose, Purshia subintegra (Kearney) Henrickson is a xeric rosaceaeous evergreen shrub with pale yellow flowers and entire leaves that lack glands. Usually less than 2 m tall, it is closely related to Purshia stansburiana, a widespread species that has lobed leaves with glands and stalked glands on the hypanthium. Known from four disjunct populations in central Arizona, P. subintegra usually occurs on lacustrine outcrops, which have a distinct chalky white appearance. The largest population occurs in the Verde Valley, where a Pliocene limestone deposit called the Verde Formation forms finger-like protrusions into the basin (Phillips et al. 1996).
Distribution & Occurrence
Plants seem to be restricted to a single layer of chalky white lake deposit limestone, which form the top layer of finger-like mesas. (USFWS 1995)
|This species is found in four localities in central Arizona below the Mogollon Rim. The most northern of these four locations contains the healthiest individuals, but these are threatened by road construction.|
Conservation, Ecology & Research
The species germinates after a period of cold stratification and seeds have a fairly high viability. However, the species is difficult to maintain in cultivation. It has extremely large and deep taproots in the wild.
The drought of 2001 and 2002 in this species habitat is a huge threat to its continued survival. A population viability analysis has shown that the species is undergoing a slow but steady decline in both in natural and reintroduced populations.
(Maschinski 2000; USFWS 1995)
overuse by cattle and burros
off-road vehicle traffic
From 1996-2000, the Arboretum at Flagstaff undertook a mitigation project that entailed learning how to cultivate Arizona cliffrose from cuttings of 65 plants that were threatened by the construction of one road. After a year of work, protocols were finally established for the successful cultivation of this species from cuttings. While not fast, (can take from 6 months to 1 year) this knowledge was key to saving the individuals in the population that were slated to be destroyed by the planned road.
The next step of the process was determining the methods to successfully reintroduce this desert plant into its native habitat. To do this, The Arboretum at Flagstaff conducted 4 experimental reintroduction trials, and found that growing the cuttings in native soil, transplanting them to the reintroduction in February, and watering them for over 5 months resulted in the greatest survival. As of 2002, the results were somewhat promising, as some of the individuals in the reintroduced population were able to survive a second year of drought--the worst in recorded history in the area. (Maschinski 2000)
Baggs, J.E.; Maschinski, J. Detecting morphological and growth rate differences of a confusing Purshia complex using a common garden study. Ecological Section. Botany 2001 "Plants and People"; August 12 - 16, 2001; Albuquerque Convention Center: Albuquerq
Baggs, J.E.; Maschinski, J. The threat of Increasing Hybridization of an Endangered Plant Species, Purshia subintegra, in the Verde Valley, Arizona. Southwestern rare and endangered plants: proceedings of the third conference; September 25-28; Flagstaff,
Baggs, J.E.; Maschinski, J.. From the Greenhouse to the Field: Cultivation Requirements of Arizona Cliffrose. Southwestern rare and endangered plants: proceedings of the third conference; September 25-28; Flagstaff, AZ. In: Maschinski, Joyce; Holter, Loue
Kartesz, J.T. 1996. Species distribution data at state and province level for vascular plant taxa of the United States, Canada, and Greenland (accepted records), from unpublished data files at the North Carolina Botanical Garden.
Phillips, B.; Lutz, D.; Popowski, R.; Shaw, H. The Verde Valley Sonoran Desertscrub: An Ecosystem at Risk. Gen. Tech. Rep. RM-GTR-283. Proceedings of the Southwestern Rare and Endangered Plant Conference; September 11-14; Flagstaff, AZ. In: Maschinski, J.
Weber, W.A.; Wittmann, R.C. 1996. Colorado flora: Eastern slope. Niwot, Colorado: Univ. Press of Colorado. 524p.