California Rare Plant Rank: 1B.2, Rare, threatened, or endangered in California and elsewhere, fairly endangered in California.

Legal Status State: Not state listed California Rare Plant Rank: 1B.2, Rare, threatened, or endangered in California and elsewhere, fairly endangered in California. Federal: Not federally listed Critical Habitat: No critical habitat has been designated for this species. Recovery Planning: No recovery plan for this species. Notes: No status changes proposed or anticipated during the permit term. Taxonomy Recurved larkspur is a perennial herb in the buttercup family (Ranunculaceae). It was described by E. L. Greene (1889:285), who noted that it was frequent in moist, subsaline grounds along the San Joaquin River from Antioch to Tulare. Davis (1900:440), and later Jepson (1914:524), proposed that recurved larkspur be regarded as a variety of Delphinium hesperium. However, this proposal was rejected by all later botanists, and the most recent treatments of Delphinium accept recurved larkspur at species rank (Warnock 1997:215; Koontz and Warnock 2012:1,141). Recurved larkspur is known to hybridize with several other larkspur species (Warnock 1997:215). Descriptions of recurved larkspur s physical characteristics and discussions of how the species can be distinguished from other similar larkspurs can be found in Warnock (1997:215) and Koontz and Warnock (2012:1,141). Distribution General Recurved larkspur is endemic to California. It is distributed primarily throughout the western and southern San Joaquin Valley from Contra Costa County to Kern County, with additional occurrences in the interior South Coast Ranges, Carrizo Plain, and western Mojave Desert (Antelope Valley) (Koontz and Warnock 1

2012:1,181; Consortium of California Herbaria 2012). It also occurred historically in the Sacramento Valley (Koontz and Warnock 2012:1,181). Distribution and Occurrences within the Study Area Thirty-five element occurrences of recurved larkspur are known to be present in Kern County (California Department of Fish and Game 2012). Only three of these element occurrences are present in the permit area. Historical Historically, recurved larkspur probably was abundant in the Kern River Delta and on the floodplains between Buena Vista Lake and Tulare Lake. However, few collections document the historic extent of the species. In 1935, recurved larkspur was collected from four miles west of Bakersfield near the present location of California State University, Bakersfield (Consortium of California Herbaria 2012; California Department of Fish and Game 2012). This occurrence element (EO# 21) is presumed extant, although the population has not been relocated since the original collection, and most of the natural habitat in this area has been urbanized. Recent Two other recurved larkspur element occurrences in the permit area are located south of the Kern River and east of Interstate 5 (California Department of Fish and Game 2012). One element occurrence (EO #31) consisted of a single plant observed in 1992 in an area adjacent to the Ten Section Oil Field. The second element occurrence (EO #93) consisted of three plants observed in 2006 in an area south of State Route 119 (Taft Highway). Both of these element occurrences are presumed extant, as the habitat at both locations remains undeveloped. Natural History Habitat Requirements Recurved larkspur is associated with alkaline habitats, primarily with alkaline grasslands, allscale (Atriplex polycarpa) scrub, and spinescale (Atriplex spinescens) scrub, although it sometimes occurs in iodine bush (Allenrolfea occidentalis) scrub and mesquite (Prosopis glandulosus) thickets (Koontz and Warnock 2012:1,181; California Department of Fish and Game 2012). It generally occurs on loam soils (sandy loam, loam, and clay loam) that are moderately to strongly alkaline and well-drained to moderately well-drained 1. Most of the populations range in 1 Soils information determined by overlaying the occurrence locations over SSURGO soils maps using SoilWeb (California Soil Resources Lab 2012). 2

elevation from 3 meters (m) (10 feet) on the valley floor up to 365 m (1,200 feet) in the adjacent foothills. A few populations in the Antelope Valley, Carrizo Plain, and interior South Coast Ranges are found at elevations between 425 m (1,400 feet) and 685 m (2,250 feet) (California Department of Fish and Game 2012). Species commonly associated with recurved larkspur include annual grasses (Bromus spp., Festuca spp., Hordeum spp.), alkali sacaton (Sporobolus airoides), common spikeweed (Centromadia pungens), bush seepweed (Suaeda nigra), alkali heath (Frankenia salina) (California Department of Fish and Game 2012). Table 1. Habitat Associations for Recurved Larkspur Land Cover Type Habitat Designation Habitat Parameters Rationale Alkali Grassland Primary Below 1,200 feet, on alkaline loam soils Saltbush Scrub Primary Below 1,200 feet, on alkaline loam soils California Department of Fish and Game 2012 Notes: Wasco, Kimberlina, Tennco, and Calflax soil series Reproduction Little information on reproduction in recurved larkspur is known. The species blooms from March to early May (Warnock 1990). Larkspur species are self-compatible (capable of producing seeds by pollen from the same plant) (Lewis and Epling 1959; Waser and Price 1991; Bosch et al. 1998; Williams et al. 2001), but because larkspur flowers are protandrous (staminate and pistillate phases temporally separated, with pollen produced and shed before the stigmas become receptive) (Waser 1978; Richter et al. 1994; Bosch et al. 1998), pollinators are required for seed set. The primary pollinators of larkspur species are bumblebees and hummingbirds, although other bee species, flies, and butterflies also visit the flowers (Macior 1975; Waser 1978; Richter et al. 1994; Bosch et al. 1998; Elliot and Erwin 2009). Table 2. Key Seasonal Periods for Recurved Larkspur Jan Feb Mar April May June July Aug Sep Oct Nov Dec Germination Blooming Seed Dispersal Sources: Notes: 3

Ecological Relationships Recurved larkspur is probably pollinated by bumblebees, although other floral visitors may effect some pollination. Therefore, conservation and management of the pollinator fauna will also need to be part of the conservation strategy for recurved larkspur. The effect of drought on recurved larkspur is not known. However, recurved larkspur is likely to survive periods of drought through dormancy of its perennial underground structures. Drought may affect seedling establishment, and it is likely to affect whether or not plants bloom. Therefore, monitoring during drought years may provide little information on the status of the populations. Population Status and Trends Global: Of 91 known occurrences of recurved larkspur, 2 have been extirpated, and 55 are known only from historic records (before 1993). Thirty-four populations have been revisited or discovered since 1992. The population status is good to excellent for 24 occurrences (26.4%) and fair for 7 occurrences (7.7%). The population status of 58 occurrences is unknown. Population trends are not known for any occurrences (California Department of Fish and Game 2012). State: Same as above Study Area: Two of the recurved larkspur occurrences in the study area are reported to be in fair condition, and the status of one occurrence is unknown. Population trends for the occurrences in the study area are unknown; however, the number of reported plants was extremely low for both occurrences. Threats and Environmental Stressors The primary threat to recurved larkspur has been the conversion of habitat through agriculture, urban development, oil field development, road and utilities construction, and landfill expansion (California Department of Fish and Game 2012). Environmental stressors to the remaining occurrences included livestock grazing and trampling, competition from nonnative plants, and litter and trash dumping (California Department of Fish and Game 2012). 4

Conservation and Management Activities Recurved larkspur has been a covered species under several HCPs that have been implemented within the study area, including the ARCO Coles Levee HCP, the Kern Water Bank HCP, the Nuevo-Torch HCP, and the Seneca and Enron Oil and Gas HCP (U. S. Fish and Wildlife Service 2013). These documents were not reviewed during preparation of this species account. Data Characterization Information on the habitat requirements of recurved larkspur appears to be adequate for modeling the species distribution in the study area. As with most plants, almost no specific information exists about the life history of recurved larkspur. However, generalized information about the life history of larkspurs is available from studies of other larkspur species and is likely to be adequate to address species management or other conservation measures for recurved larkspur. Management and Monitoring Considerations The current population status and habitat condition are currently unknown for the occurrences in the study area. Effective management measures cannot be determined until the populations have been surveyed to determine these parameters. Some general measures that are likely to be applicable would be fencing to manage the effects of grazing and trampling by livestock and removal or control of invasive plant species. Modeled Species Distribution in Study Area Model Description Model Assumptions Primary Habitat: Annual grassland and saltbush scrub, below 1,200 feet elevation, on the following soil series: Wasco, Kimberlina, Tennco, and Calflax. Secondary Habitat: Annual grassland and saltbush scrub, below 1,200 feet elevation, on the following soil series: Milham, Panoche, Garces, and McFarland. Model Rationale Recurved larkspur is associated with alkaline habitats, primarily with alkaline annual grasslands and saltbush (Atriplex spp.) scrub(koontz and Warnock 2012:1,181; California Department of Fish and Game 2012). It generally occurs on loam soils (sandy loam, loam, and clay loam) that are moderately to strongly alkaline and 5

well-drained to moderately well-drained, and in the study area this includes soils in the Wasco, Kimberlina, and Tennco series. Other soil series associated with these three soils include Milham, Panoche, Garces, and McFarland (U.S. Department of Agriculture, Soil Resources Survey 2012a, 2012b, 2012c). Model Results Figure D-14 shows the modeled potential habitat for recurved larkspur within the study area. Most of the occurrences in the study area fall within the modeled habitat. Within the Plan Area, modeled habitat is located primarily along the west side near the junction of Interstate 5 and the Taft Highway. Literature Cited Bosch, M., J. Simon, J. Molero, and C. Blanche. 1998. Reproductive Biology, Genetic Variation and Conservation of the Rare Endemic Dysploid Delphinium bolosii (Ranunculaceae). Biological Conservation 86:57 66. California Department of Fish and Game. 2012. California Natural Diversity Database, RareFind 3, Version 3.1.0. Updated June 1, 2012. Report for Delphinium recurvatum. Sacramento, CA. California Soil Resources Lab. 2012. SoilWeb: An Online Soil Survey Browser. University of California, Davis. Available: <http://casoilresource.lawr.ucdavis.edu/drupal/book/export/html/902>. Accessed October 2012. Consortium of California Herbaria. 2012. Herbarium records for Delphinium recurvatum. Data provided by the participants of the Consortium of California Herbaria. Available: <http://ucjeps.berkeley.edu/consortium/>. Accessed: July 19, 2012. Davis, K. C. 1900. Native and Garden Delphiniums of North America. Minnesota Botanical Studies 2:431 457. Elliott, S. E., and R. E. Erwin. 2009. Effects of Flowering Plant Density on Pollinator Visitation, Pollen Receipt, and Seed Production in Delphinium barbeyi (Ranunculaceae). American Journal of Botany 96(5):912 919. Greene, E. L. 1889. New or Noteworthy Species. IV. Pittonia 1:280 287. Jepson, W. L. 1914. A Flora of California, Vol. 1. University of California: Berkeley, CA. Koontz, J. A., and M. J. Warnock. 2012. Delphinium. In The Jepson Manual: Vascular Plants of California, Second Edition, edited by B. G. Baldwin, D. H. Goldman, D. J. Keil, R. Patterson, T. J. Rosatti, and D. H. Wilken, pp. 1136 1142. University of California Press: Berkeley, CA. 6

Lewis, H. and C. Epling. 1959. Delphinium gypsophilum, a Diploid Species of Hybrid Origin. Evolution 13:511 525. Macior, L. W. 1975. The Pollination Biology of Delphinium tricorne. American Journal of Botany 62(10):1009 1016. Richter, P., S. Soltis, and D. E. Soltis. 1994. Genetic Variation within and among Populations of the Narrow Endemic, Delphinium viridescens (Ranunculaceae). American Journal of Botany 81(8):1070 1076. Warnock, M. J. 1990. Taxonomic and Ecological Review of California Delphinium. Collectanea Botanica 19:45 74.. 1997. Delphinium. In Flora of North America North of Mexico, Vol. 3: Magnoliophyta: Magnoliidae and Hamamelidae, edited by Flora of North America Editorial Committee, pp. 196 240. Oxford University Press: New York and Oxford. Waser, N. M. 1978. Competition for Hummingbird Pollination and Sequential Flowering in Two Colorado Wildflowers. Ecology 59(5):934 944. Waser, N. M., and M. V. Price. 1991. Outcrossing Distance Effects in Delphinium nelsonii: Pollen Loads, Pollen Tubes, and Seed Set. Ecology 72:171 179. Williams, C. F., J. Ruvinsky, P. E. Scott, and D. K. Hews. 2001. Pollination, Breeding System, and Genetic Structure in Two Sympatric Delphinium (Ranunculaceae)Species. American Journal of Botany 88(9):1623 1633. United States Department of Agriculture, Natural Resources Conservation Service. 2012a. Official Soil Series Descriptions: Wasco Series. Available: <https://soilseries.sc.egov.usda.gov/osd_docs/w/wasco.html>. Accessed October 2012.. 2012b. Official Soil Series Descriptions: Kimberlina Series. Available: <https://soilseries.sc.egov.usda.gov/osd_docs/k/kimberlina.html>. Accessed October 2012.. 2012c. Official Soil Series Descriptions: Tennco Series. Available: <https://soilseries.sc.egov.usda.gov/osd_docs/t/tennco.html>. Accessed October 2012. United States Fish and Wildlife Service. 2013. Species profile for recurved larkspur. Available: http://ecos.fws.gov/speciesprofile/profile/speciesprofile.action?spcode=q32h. Accessed: January 2013. 7

B a k e r s f i e l d C o n s e r v a t i o n P l a n W hi t e R i v e r K:\Projects_1\City_of_Bakersfield\00036_12_BakersfieldHCP\mapdoc\Species_Model_Figures\D_14_Recurved_larkspur_figure.mxd hw 2/1/2013 M O N T E R E Y S A N L U I S O B I S P O S a n River / Creek J ua n Cr e e k Major Roadway County Boundary HCP Study Area HCP Permit Area Recurved larkspur CNDDB Occurrence (Presumed Extant) Primary Habitat Source: City of Bakersfield 2012; CNDDB 2012 0 5 10 15 Miles UV 58 K I N G S 5 T E M B L O R R A N G E C A L I E N T E R A N G E UV 33 Lost Hills S A N T A B A R B A R A S I E R R A M A D R E R A N G E Cuyama Riv er Buttonwillow UV 43 UV 119 UV 99 Taft P o s o C Wasco V E N T U R A r e e k Delano Shafter Bakersfield S A N E M I G D I O M O U N T A I N S Oildale K E R N T U L A R E K E R N Lamont Arvin P o s o C r e e k UV 58 K er n R i v e r Bear Valley Springs S I E R R A V A D A N E UV 178 T E H A C H A P I M O U N T A I N S Figure D-14 Recurved larkspur Modeled Habitat