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The White-Margined Penstemon (Penstemon albomnrginn tus Jones), a Rare Mohave Desert Species, and the Hualapai Mountains Land Exchange in Mohave County, Arizona JOHN L. ANDERSON U.S. Bureau of Land Management, Phoenix, Arizona Abstract: The white-margined penstemon (Penstemon albonzargimtzls Jones) is a rare Mohave Desert species with an unusual tripartite distribution with disjunct localities in Arizona, California, and Nevada. The Arizona population is the largest single population occurring with a range of 15 miles by 5 miles in Dutch Flat near Yucca, Arizona in Mohave County. The land ownership pattern in Dutch Flat was a checkerboard of public and private land, a legacy of railroad lands. Although the Bureau of Land Management (BLM) designated the white- margined penstemon Area of Critical Environmental Concern (ACEC) in 1993 for conserva- tion of this Arizona BLM sensitive species, the checkerboard pattern of public and private lands within the ACEC made its conservation management difficult. Rural development was increasing impacts to the Dutch Flat area as the private land was being sold off in 40 acre parcels. The Hualapai Mountains Land Exchange between the Santa Fe Pacific Railroad and the BLM provided a tool for consolidating a portion of the ACEC into a solid block of public land, thereby increasing its manageability for the conservation and survivability of the white- margined pens temon. A real estate artifact of the westward U.S. expan- lic lands selected by the proponent) and 70,000 sion in the nineteenth century is the large areas of acres of offered lands (private lands offered to the checkerboard land ownership patterns between BLM by the proponent). The area covered by the public and private land. To encourage pioneer Hualapai Mountains Land Exchange contained settlement, the federal government gave railroad occupied habitat of a rare Mohave Desert plant companies every other section (the odd-numbered (BLM 1995), Penstemon albomarginatrrs Jones, the sections) along railroad routes they constructed. white-margined penstemon (Figure 4), a member Because of the resultant checkerboard land owner- of the Figwort family (Scrophulariaceae). An anal- ship pattern, there are no large areas of contiguous ysis of the impacts of the Hualapai Mountains ownership; consequently, these areas are both Land Exchange on the white-margined penstemon hard to manage for natural resource values on and its habitat was conducted to determine wheth- public land (either federal or state) and hard to er the effects of the exchange to the plant would be develop for private land owners. Throughout the positive or negative (BLM 1998). West, the Bureau of Land Management (BLM) has Penstemon nlbomnrginatrrs was described by entered into various land exchanges with private Marcus Jones (1908), who said it was "a most con- land owners to consolidate federal land ownership spicuous and remarkable plant." It is indeed a to facilitate natural land resource management distinctive species that has never been confused and protection of special habitats and species (Los with any other species of Penstemon. A member of Angeles Times 2000). In Mohave County, Arizona, subgenus Penstemon, which is characterized by one such checkerboard example is the Dutch Flat glabrous anthers that dehisce the full length and and Hualapai Mountains area east of Interstate 40 are usually widely spreading, Pensfemon albomnr- and approximately 20 miles south of Kingman ginntus is a low growing plant 15-35 cm tall with (Figure 1).Here, the private land was originally several herbaceous stems arising from a buried owned by the Atchison, Topeka, and Santa Fe Rail- root crown. It has a glabrous inflorescence of road (Figure 2). medium-sized, lavender-pink, campanulate flow- In 1997 the BLM and the Santa Fe Pacific ers, 13-17 mm long, with a glabrous staminode Railroad, through its representative, Ironhorse and yellow hairs in the throat. The most distin- Investors (the proponent), began the Hualapai guishing morphological character of the white- Mountains Land Exchange (Figure 3) involving margined penstemon is the scarious white margins approximately 70,000 acres of selected lands (pub- of the leaves, which are lanceolate to oblanceolate, soon activity. For much of the year it is not visible above ground. As a rare plant, Penstemon albomarginata has an unusual tripartite distribution pattern in the Mohave Desert (Scogin 1989). It occurs in three widely disjunct localities between three states- Arizona, Nevada, and California. The Arizona locality in Dutch Flat near Yucca is the single larg- est occurrence, extending in a band approximately 15 miles long and 5 miles wide along the western base of the Hualapai Mountains and Dutch Flat between Rock Creek on the northwest to Cow Creek on the southeast, although the entire area does not contain the appropriate soil habitat (Fig- ure 5). Nevada has the widest scattered colonies (approximately 15 colonies) in two metapopula- tions over a hundred miles apart, one at Jean- Goodsprings 30 miles southwest of Las Vegas and one at Amargosa Valley 80 miles northwest of Las Vegas. California has the smallest occurrence, one 4 mile long population of scattered colonies 30 miles east of Barstow at Sleeping Beauty Mountain (MacKay 1999). At all three widely separated localities, the Figure 1. Subject area location within Arizona. white-margined penstemon grows on a similar habitat-sandy soils-but these sandy soils are of different origins. In California and Nevada the usually entire, and shiny glabrous with a bluish plants occupy stabilized sandy soils derived from green color. colluvial sand deposits (personal observation), In his type description, Jones (1908) cited whereas in Arizona the plants occupy sandy loam specimens from Good Springs Station, Nevada, in uplands on alluvial fan terraces, and a smaller 1905, and Yucca, Arizona, where he had first col- number of plants also occupy sandy wash bot- lected it more than 20 years earlier on May 19, toms. There is also a difference in associated vege- 1884 (in the area of the Hualapai Mountains Land tation of the white-margined penstemon between Exchange). Ironically, his 1884 trip to the Yucca Arizona and the other two states. In Arizona the area was probably made possible by the comple- white-margined penstemon occurs with Joshua tion that year of the Santa Fe Railroad to Needles, tree (Yucca brevifolia Engelm.) and mixed shrub California (Lenz 1986). Jones (cited in Lenz 1986) association (Brown 1982), primarily creosotebush wrote that "The whole spring flora was collected (Larrea tridentata (DC) Coville) and white bursage at Yucca and the desert was a perfect garden in all (Ambrosia dumosa (Gray) Payne) with big galleta directions, never was as good for 20 years after- grass (Pleuraphis rigida Thurb.), whereas in Nevada wards." The white-margined penstemon is one of and California it occurs with simply the creosote- the few Penstemon species that grows exclusively bush and white bursage association (Brown 1982), at low elevations in the Mohave Desert (Kearney and Joshua trees are not present (personal obser- and Peebles 1960, Munz 1974); others are Penste- vation). In degraded habitats rayless goldenhead mon bicolor (T. S. Brand.) Clokey & Keck ssp. roseus (Acamptopappus sphaerocephalus (Gray) Gray) and Clokey and Keck and Penstemon subulatus A. Nels. burro bush (Hymenoclea salsola T & G) increase as As an adaptation to the arid conditions of Mohave associated species. There is seemingly much po- Desert valleys, the white-margined penstemon is tential sandy soil habitat for the white-margined an "ephemeral" perennial whose stems die back to penstemon between the existing sites that does not the ground after the spring growing season and contain the plant. The reasons for its disjunct dis- during the hot, dry Mohave Desert summer and tribution pattern, whether biological or physical, the cold Mohave Desert winter. Occasionally, the are unknown but this pattern probably indicates plant will green up in late summer if there is mon- that the Penstemon albomarginatus is a relict species. Legend I White Margin Penstemon Habitat Land Status - Pre-Santa Fe Exchange White Margin Pensternon ACEC I I Private In State I BLM Figure 2. Checkerboard land status pattern in Hualapai Mountains-Dutch Flat area. Legend White Margin Penstemon Habital Land Status - Pre-Santa Fe Exchange 0 White Margin Penstemon ACEC private Shte BLM Land Selected by Proponent Private Land Offered by Proponent a BLM S Figure 3. Selected and offered lands of the Hualapai Mountains Land Exchange. Figure 4. Penstemon albomarginatus Jones. 31 Soil Units Soil Units with White-Margin Pensternon Soil Units without White-Margin Pensternon Figure 5. Soil units with white-margined penstemon present. Penstemon albomarginatus is a BLM sensitive Conservation Service 1996). Based on field obser- species; it was a Category 2 candidate species vations, the Kingman Field Office BLM soil scien- under the old U.S. Fish and Wildlife Service rank- tist, Paul Hobbs, and the author defined which ing. The Kingman Resource Area Resource Man- soils were habitat, soil mapping units 50, 54, 54B, agement Plan (BLM 1995) designated Dutch Flat as and 150B, and which soils were not habitat, soil the white-margined penstemon ACEC to protect mapping units 52, 73, and 76. These soil mapping the best-quality habitat of the species. However, units are also given ecological site names in the the ACEC contained a checkerboard land owner- NRCS report, which are used here. The primary ship pattern of roughly equal amounts of public ecological site supporting the white-margined land, 17,489 acres, and private land, 16,038 acres, penstemon is the sandy loam upland in the 6-12 making management of the white-margined pen- precipitation zone; fewer plants grow on clay loam stemon difficult. The management prescriptions uplands (the surface texture of this unit is still a for the ACEC in the Kingman Resource Area sandy loam) and along sandy (wash) bottoms.

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