Vernal barley Hordeum intercedens Class: Liliopsida Order: Cyperales Family: Poaceae Dudek and Associates Species Accounts Status: Federal: None State: None Data Characterization Data reviewed includes the herbarium specimens at Rancho Santa Ana Botanical Gardens, Clairmont, the University of California, Riverside, GIS data base, and available literature. The California Natural Diversity Data Base (CDFG) does not include this species. Twelve specimens of vernal barley are at Rancho Santa Ana Botanical Garden. The UC, Riverside GIS data base includes eight localities, apparently all based on the Rancho Santa Ana material. Five collections are associated with Salt Creek west of Hemet and six collections are associated with the San Jacinto River primarily north of the Ramona Expressway. A single collection represents the wetlands near Nichols Road north of Lake Elsinore. This last locality is mapped too far south in the UCR GIS data base. Very little literature is available regarding vernal barely. What is available focuses on systematics. While the distribution of key populations within western Riverside County are relatively well understood because of their close links with the alkali vernal plains habitats, the overall distribution of this species in the planning area is poorly known. It is expected to occur in the Temecula-Murrieta area, the Santa Rosa Plateau, and perhaps the Anza area. Habitat and Habitat Associations Vernal barley is associated with mesic grasslands, vernal pools, and large saline flats or depressions (Braum and Bailey 1987; Skinner and Pavlik 1994). In Riverside County, vernal barley is found in the Dominio-Willows-Traver Soils series and is associated with alkali flats and flood plains within the alkali vernal plains community (Ferren and Fiedler 1993). Within this community vernal barley is primarily associated with alkali annual grasslands and vernal pools and to a lesser extent alkali scrub and alkali playa (F. Roberts, botanist, in litt., September 1999). Associated species include: seablite (Suaeda moquinii), alkali weed (Cressa truxillensis), wire-stem popcorn flower (Plagiobothrys leptocladus), sand spurry (Spergularia marina), California goldfields (Lasthenia californica), Mojave silver scale (Atriplex argentea), San Jacinto Valley crownscale (A. coronata var. notatior), bracted saltbush (A. serenana), five-hook bassia (Bassia hyssopifolia), sharp-tooth peppergrass (Lepidium dictyotum), dwarf peppergrass (Lepidium latipes), little mousetail (Myosurus minimus var. apus), alkali heath (Frankenia grandifolia), smooth tarplant (Hemizonia pungens ssp. laevis), and toad rush (Juncus bufonius) (Bramlet 1993; F. Roberts, in litt., 1999). The distribution of vernal barley in San Diego and Orange County suggests that this species may occur in mesic grasslands, hard and basaltic vernal pool habitats within Riverside County. Biogeography Vernal barley occurs in scattered locations bordering the Central Valley of central California, southwestern California, and northwestern Baja California, Mexico, below 1,000 meters elevation (Barkworth 1993). In southern California it has been reported from Orange, Riverside, and San Diego Counties. In Mexico, it has been reported as far south as Punta Blanca about 130 km south of El Rosario (Reiser 1996). Range The distribution of Hordeum intercedens is not well understood in western Riverside County. However, known populations appear to be closely associated with the distribution of alkali soils and the alkali vernal plains community. The majority of recent collections are from the Upper Old Salt Creek drainage area west of Hemet and along the San Jacinto River floodplain from Mystic Lake south to at least the I-215 where it occurs in extensive stands forming the dominant element of the alkali annual grassland community (Ogden 1996; F. Roberts, in litt., 1999). The species likely occurs in other areas such as the Santa Rosa Plateau. Key Populations in Planning Area Three key populations of vernal barley have been identified within the planning area: the San Jacinto Wildlife Area, the middle segment of the San Jacinto River from Ramona Expressway south to Railroad Canyon, and the Salt Creek area west of Hemet. In its undisturbed condition, the population at Salt Creek as a local dominant over 200 to 400 hectares. Biology Genetics: Vernal barley, a member of the Poaceae, is one of about 30 species of Hordeum (Barkworth 1993). It is closely allied to, and often confused with Hordeum depressum, another alkali favoring species, and H. pusillum (Braum and Bailey 1987). Reproduction: No studies are available regarding the reproductive biology of vernal barley. Dispersal: No studies are available regarding the dispersal of vernal barley seeds. Threats This species and its habitat is threatened by urbanization, agricultural conversion, discing, trampling from livestock, channelization, and alteration of hydrology (U.S. Fish and Wildlife Service 1998). Special Biological Considerations Low, obscure, and difficult to distinguish from other barley species. This species blooms from March to June (Skinner and Pavlik 1994). Population size varies considerably from year to year depending upon rainfall, local flooding, and disturbance. Hordeum intercedens has previously been misidentified as Hordeum depressum at many locations, including Hemet and along the San Jacinto River. References to H. depressum in documents regarding San Jacinto Valley crownscale and spreading navarretia in recent listing actions (U.S. Fish and Wildlife Service 1998) represent misapplied references to vernal barely. Literature Cited Barkworth, M. 1993. Hordeum, in The Jepson Manual, Higher Plants of California, J.C. Hickman, edit.,University of California Press, Berkeley, California. Bramlet, D. 1993. Plant species of special concern in the alkaline sinks of the San Jacinto River and the Old Salt Creek tributary area. Unpublished Report. Braum, B.R., and L.G. Bailey 1987. A taxonomic study of the annual Hordeum depressum and related species. Canadian Journal of Botany 66: 401-408. Ferren, W.R., and P.L. Fiedler 1993. Rare and threatened wetlands of Central and Southern California, in Interface between Ecology and Land Development in California, J.E. Keely editor, Southern California Academy of Sciences, Los Angeles. Ogden 1996. Mitigation site surveys for the Eastside Pipeline project. Prepared for Metropolitan Water District of southern California, Los Angeles, California. Reiser, C. 1996. Rare Plants of San Diego County, 1996 edition. Unpublished. Aquafir Press, San Diego, California. Skinner M.W., B.M. Pavlik. 1994. California Native Plant Society's Inventory of Rare and Endangered Vascular Plants of California, Special Publication, 5th ed., California Native Plant Society. U.S. Fish and Wildlife Service 1998. Endangered and Threatened Wildlife and Plants; Determination of Endangered or Threatened Status for Four Southwestern California Plants from Vernal Wetlands and Clay Soils. Federal Register 63 (197): 54975 - 54994.