Slender-lobed Four O'Clock [Mirabilis tenuiloba Wats.]
Listing CNPS List 4 R-E-D Code 1-1-1
State/Federal. Status -- None NYCTAGINACEAE Mar.-May
Global Rank G3? State Rank S?
Distribution: San Diego County, Imperial County; Baja California, Mexico
Habitat: Sonoran Desert Scrub on sandy, gravelly, or rocky slopes is the preferred habitat of this herbaceous perennial. Sites examined in The Anza-Borrego Desert were xeric, but relatively well protected locales near boulders.
Known Sites: Slender-lobed Four O'Clock is seen occasionally in desert canyons as in Meyers Creek. It is also found on the Borrego Palm Canyon Nature Trail. Herbarium specimens are from the Jacumba Mountains and in Borrego Palm Canyon. Old reports are from Mount Tule/Carrizo Gorge, The Narrows, North Mortero Wash, and Lava Flow Wash. This shrub is occasional alongside washes east of Coyote Wells, and in rugged canyons south of Pinto Wash in Imperial County.
Twenty collections from Baja California are found in the herbarium of the San Diego Natural History Museum; south to 25 51' North where collected by Moran (SD 66783) on a broad sandy wash near Marquer Bay.
Status: Slender-lobed Four O'Clock populations in San Diego County are likely stable based on the limited historical impacts to its desert habitat. It may be overlooked due its superficial similarity with white flowering forms of Mirabilis bigelovii, a common desert species. More collection data is needed. Provisionally, it is recommended that substantial portions of all sizeable populations be protected.
Copyright © May 1994 Craig H. Reiser.
Back to Craig H. Reiser's Rare Plants of San Diego County