(DRAFT) - Taxonomy
                       Species EVENING-PRIMROSE, EUREKA VALLEY
                                Species Id ESIS701024
                                   Date 13 MAR 96



TAXONOMY

NAME - EVENING-PRIMROSE, EUREKA VALLEY OTHER COMMON NAMES - EVENING-PRIMROSE, EUREKA VALLEY;EVENING-PRIMROSE, EUREKA DUNES; PRIMROSE and EUREKA ELEMENT CODE - CATEGORY - Angiosperm PHYLUM AND SUBPHYLUM - MAGNOLIOPHYTA, CLASS AND SUBCLASS - MAGNOLIOPSIDA, ORDER AND SUBORDER - MYRTALES, FAMILY AND SUBFAMILY - ONAGRACEAE, GENUS AND SUBGENUS - OENOTHERA, SPECIES AND SSP - AVITA, SSP. SCIENTIFIC NAME - OENOTHERA AVITA SSP. AUTHORITY - TAXONOMY REFERENCES - COMMENTS ON TAXONOMY - Eureka Valley Evening-primrose Oenothera avita ssp. eurekensis (Munz & Roos) W. Klein KINGDOM: Plant GROUP: Angiosperm DIVISION: Magnoliophyta CLASS: Magnoliopsida ORDER: Myrtales FAMILY: Onagraceae A suffrutescent perennial herb, stems and herbage white-storage and +/- spreading-villous (03,08,09). Stems arising from deep-seated, fleshy underground parts. Much of the year in a rosette stage; leaves crowded, deltoid-ovate 1-3.5 cm long. In spring (with sufficient moisture) plants bolt producing often rather bushy stems 3-6 cm tall (up to 1 m). Flowers solitary in the axils of leaves from the base of the stem upwards; large, conspicuous, vespertine, perfect. Sepals 4, recurved at anthesis. Petals 4, white, 1.5-2.5 cm long, aging to reddish. Stamens 8. Stigma with 4 linear lobes. Ovary inferior, narrow cylindric with prolonged floral tube. Fruit a dehiscent capsule 2.5-3 cm long. In summer, after seed set, all leaves fall and new rosettes formed at the tips of the old fruiting shoots; sand burial often then returns the plant to a rosette stage (03,09,10). The first material from Eureka Dunes was assigned to the Oenothera deltoides complex as subspecies eurekensis (09,10). Its Taxonomy - 1 (DRAFT) - Taxonomy Species EVENING-PRIMROSE, EUREKA VALLEY Species Id ESIS701024 Date 13 MAR 96 distinguishing features within this taxon were its perennial, suffrutescent habit and densely villous herbage. Later, Klein allied the subspecies with Oenothera california (07) on the basis of its tendency to perenniate from underground rootstocks and its non-woody fruit capsules (10). Still later Klein placed it in a new species complex, Oe. avita of eastern California and western Arizona (08,10). This is the most current treatment and is supported by karyological data (Oe. avita with n=7, Oe. a. ssp. eurekensis with n=7, whereas Oe. californica is n=14) (08,10). Scientific names associated with this subspecies are: Oenothera deltoides ssp. eurekensis, Oe. californica ssp. eurekensis, and Oe. avita ssp. eurekensis (07,08,09). Common names associated with the subspecies are: Eureka Valley evening-primrose, Eureka Dunes evening-primrose, and the Eureka Primrose. Type specimens: Munz & Roos 20, 158, 18 Sept. 1954 (RSA; isotypes: CAS, DS, UC) (03). Illustrations are included in the following references: 02,03,05,09, and 10. Taxonomy - 2
                                  (DRAFT) - Status
                       Species EVENING-PRIMROSE, EUREKA VALLEY
                                Species Id ESIS701024
                                   Date 13 MAR 96



STATUS

Coded Status E: Federal Endangered COMMENTS ON STATUS - U.S. STATUSES AND LAWS: The Eureka Valley evening-primrose (Oenothera avita ssp. eurekensis) has been designated Endangered pursuant to the Endangered Species Act of 1973 (50 CFR 17.12; P.L. 93-205, 87 Stat. 884; 16 U.S.C. 1531-1540), as amended. The subspecies has this status wherever found including the State of California. Removal and reduction to possession of any federally listed plant from an area under Federal jurisdiction is unlawful (50 CFR 17.61 and 17.71). This subspecies is protected by the Lacey Act (P.L. 97-79, as amended; 16 U.S.C. 3371 et seq.) which makes it unlawful to possess any wild plant (including roots, seeds, and other parts) within U.S. territorial or special maritime jurisdiction (as defined in 18 U.S.C. 7); or to import, export, transport, sell, receive, acquire, or purchase in interstate or foreign commerce any wild plant (including roots, seeds, and other parts) taken, possessed, transported, or sold in violation of any State law or regulation. It is also unlawful to import, export, transport, sell, receive, acquire, or purchase any wild plant (including roots, seeds, and other parts) taken or possessed in violation of any U.S. law, treaty, or regulation or in violation of Indian tribal law. RESPONSIBLE FEDERAL AGENCIES: USFWS -Responsible for the management/recovery, listing, and law enforcement/protection of this species. BLM -Responsible for the law enforcement/protection of this species with applicable State and Federal laws on public land under their control (43 CFR 4140). Also responsible for management/recovery on Bureau of Land Management lands. All Federal agencies have responsibility to ensure that any action authorized, funded, or carried out by that agency is not likely to jeopardize the continued existence of the species or result in the destruction or adverse modification of Critical Habitat (50 CFR 402), and to utilize their authorities to carry out programs for the conservation of the species. STATE STATUSES AND LAWS: STATE: California DESIGNATED STATUS: Endangered Status - 1 (DRAFT) - Status Species EVENING-PRIMROSE, EUREKA VALLEY Species Id ESIS701024 Date 13 MAR 96 ADMINISTRATIVE AGENCY: California Dept. of Fish and Game STATE STATUTE: California Endangered Species Act; Fish and Game Code Chapt. 1.5, Art. 1, Sec. 2050. INTERNATIONAL STATUSES, TREATIES, AND AGREEMENTS: None. ECONOMIC STATUSES: None. 78/04/26:43 FR 17910/17916 - Listed as Endangered, no Crit. Hab. 83/12/08:48 FR 55100/55102 - Notice of 5 year review 85/07/22:50 FR 29900/29901 - Notice of 5 year review 85/09/27:50 FR 39526/39527 - Notice of review 87/07/07:52 FR 25523/25525 - Notice of 5 year review completion Status - 2
     

HABITAT ASSOCIATIONS

HABITAT - TERRESTRIAL TERRESTRIAL LAND USE - Shrub and Brush Rangeland Sandy Areas other than Beaches COMMENTS ON HABITAT ASSOCIATIONS - Oenothera avita ssp. eurekensis occurs from about 2900 to 4000 feet elevation, only in the southern Eureka Valley on very sandy habitats associated with arid desert sand dune systems. It occurs on the lower slopes of large active, but relatively stable, dunes (described variously as a longitudinal system or as transverse dunes with a sand mountain) (01,12), and it occurs on the obstacle type of dune system where the sand covers the spur ridges of the Saline Range (01,12). All these habitats have deep sand substrate. Oe. a. ssp. eurekensis does not occur on the mostly unstable upper slopes of the Eureka Dunes. Here, only Swallenia and Dicoria are found. It occurs on the lower dunes on slopes of 5-25 degrees that are mostly stable (10). The satellite dune areas, where Oe. a. ssp. eurekensis occurs west of the Eureka Dunes, are of moderate to gentle slope and mostly stable (01). Here, Oe. a. ssp. eurekensis also occurs well out onto sandy bajada slopes. Soils of the Eureka Dunes are alkaline (pH ranging from 8.1 to 9.3), non-saline, non-sodic, and very low in nitrogen (less than 0.06 ppm) (10). No data is available for the soils in the satellite dune areas. Little climatological data has ever been reported for the Eureka Valley (01,10,12). Summers are quite hot with daily temperatures commonly exceeding 40 degrees Celsius (104 F) in June, July and August. Winters are cool, daytime maximum temperatures are probably always above freezing, while night temperatures commonly drop below freezing from November to February (01,10,12). Average annual precipitation is probably about 115 mm (4.5 in) (10). Most of the precipitation usually falls in the cool part of the year, from November through March. Summer thunderstorms generally occurring in July and August may in some years account for a significant proportion of the years total precipitation (01,10,12). It is thought that the dunes act as an aquifer, providing the dune system with an above average supply of available soil moisture (10,12). Vegetation on the dunes where Oe. a. ssp. eurekensis occurs is very sparse and consists of few species. On the lower and more stable dune slopes, Oe. a. ssp. eurekensis is associated with Swallenia, Dicoria, Astragalus lentiginosus var. micans, Tiquilia plicata, Oryzopsis hymenoides and a few other species (01,02,05,10,12). Surrounding the dunes are Creosote Bush Scrub and Allscale-Alkali Scrub (02,10,12). Habitat Associations - 1
                                (DRAFT) - Food Habits
                       Species EVENING-PRIMROSE, EUREKA VALLEY
                                Species Id ESIS701024
                                   Date 13 MAR 96



FOOD HABITS

TROPHIC LEVEL - AUTOTROPH Food Habits - 1
                         (DRAFT) - Environment Associations
                       Species EVENING-PRIMROSE, EUREKA VALLEY
                                Species Id ESIS701024
                                   Date 13 MAR 96



ENVIRONMENTAL ASSOCIATIONS

G = General A = Adult LIM = Limiting RA = Resting Adult J = Juvenile FA = Feeding Adult RJ = Resting Juvenile BA = Breeding Adult FJ = Feeding Juvenile P = Pupae L = Larvae E = Egg RL = Resting Larvae FL = Feeding Larvae
LIFESTAGE ENVIRONMENTAL ASSOCIATIONS G G Environment Associations - 1
                               (DRAFT) - Life History
                       Species EVENING-PRIMROSE, EUREKA VALLEY
                                Species Id ESIS701024
                                   Date 13 MAR 96



LIFE HISTORY

HABIT: The Eureka Valley evening-primrose is an herb (02,03,05,07,08,09, 10,12). LIFE CYCLE: Perennial (02,03,05,07,08,09,10,12). TYPE OF REPRODUCTION: Sexual and vegetative (10,11). Oe. avita ssp. eurekensis may be capable of producing independent ramets from the rosettes that form on the floral axis or on the creeping underground rootstocks. The demographic significance of this is unknown (10,11). REPRODUCTIVE PHENOLOGY: Germination occurs from November to December. Stem and leaf growth begins in April. From late April through early July, budding and flowering occurs. Fruit is produced from May to early July. Seed dispersal begins from June to July (01,05,10). SEX OR SPORE STATUS: Monoclinous (07,08,09,10,11). POLLINATION, SPORE AND SEED DISSEMINATION: Little or nothing is known about the biology of the pollinating insect for Oenothera, hawkmoths (Sphingidae) of the genus Celerio (10,11). Flowers produced by late May and early June have a high probability of being visited by pollinators carrying compatible pollen (11). Seed dissemination is due to the wind (10,11). SEED BIOLOGY: Pavlik reports an apparent high viability of seed (90 percent), but low percent germination (10). At constant temperatures Oe. a. ssp. eurekensis exhibited a rather narrow optimum at 20 degrees Celsius, but with only 49 percent germination after 12 days; thermo-periodic alterations increased this greatly, peak germination occurred with both 5 and 10 degree alterations and was 32 percent greater than at the optimal constant temperature (10). Annual seed production is quite high, Pavlik and Barbour estimate annual seed production as about 600-700 seeds per cubic dm of canopy volume (11). This compares favorably with that of other related species (11). Estimates of seed rain were also quite high, 21,317 seeds/sq. m/year (11). Supplements of water and nitrogen in field experiments produced no significant effect on seed production (11). Pollination factors appear to be the most critical in reducing seed production relative to the maximum reproductive potential (11). Nothing is known of seed longevity and dormancy requirements. POPULATION BIOLOGY: In general, little is known about the population biology of sand dune plants in North America (11). Little is known about Oe. a. ssp. eurekensis in particular. Two studies have recently begun (01,11). Life History - 1 (DRAFT) - Life History Species EVENING-PRIMROSE, EUREKA VALLEY Species Id ESIS701024 Date 13 MAR 96 Results of Pavlik's studies on survival/mortality rates, density and population trends have not been published yet, although results of studies of seed dispersal and effects of herbivores are available (11). Studies by Bagley produced data on population density and cover but information on population trends awaits further work (01). At the north end of the Eureka Dunes measured stands of Oe. a. ssp. eurekensis range from 0 to 1010 mature plants per hectare (avg.=373/ha) with a cover of 0.3 to 0.002 percent (avg.=0.09 percent) (01). The percentage of the population in the mature age class ranged from 29 to 69 percent (avg.=50 percent) (01). ECOLOGICAL/EDAPHIC FACTORS: The Eureka Valley evening-primrose occurs only on sand dunes. Soils are psamment Entisols. Detailed data is available only for the Eureka Dunes. The Dune sands are dominated by quartz grains with some finer, dark, heavy materials of magnetite, hornblend, augite, and olivine (10,12). Grains tend to be coarse and poorly sorted on the low northern and southern toes of the dunes, but are finer and well sorted with elevation (10,12). Mean grain size of 0.30 mm is considerably larger than in the other desert dunes on Inyo County (10). Oe. a. ssp. eurekensis occurs in an arid climate, average annual precipitation is probably about 115 mm (4.5 in) (10). The dune system appears to act as an aquifer, providing an above average supply of available soil moisture (10,12). TROPHIC STATUS: Phototrophic (10). CHARACTERISTIC DOMINANCE: Component (01,05,10,12). COMMUNITY ECOLOGY: Vegetation on the dunes where Oe. a. ssp. eurekensis occurs is very sparse and consists of few species. On the lower and more stable dune slopes, Oe. a. ssp. eurekensis is associated with Swallenia, Dicoria canescens, Astragalus lentiginosus var. micans, Tiquilia plicata, Oryzopsis hymenoides and a few other species (01,02,05,10, 12). Surrounding the dunes are Creosote Bush Scrub and Allscale-Alkali Scrub (02,10,12). Nothing is known about community stability and successional trends. SPECIES INTERRELATIONSHIPS: None. OTHER LIFE HISTORY DESCRIPTORS: None. Life History - 2
                           (DRAFT) - Management Practices
                       Species EVENING-PRIMROSE, EUREKA VALLEY
                                Species Id ESIS701024
                                   Date 13 MAR 96



MANAGEMENT PRACTICES

RESULT MANAGEMENT PRACTICE Beneficial Controlling/Restricting Off-Road Vehicles Beneficial Restricting/regulating human disturbance of populations Beneficial Maintaining undisturbed/undeveloped areas Adverse Off Road Vehicles Existing Off Road Vehicles Adverse Hiking/Camping Existing Hiking/Camping Adverse Low Gene Pool Existing Low Gene Pool Adverse Erosion Existing Erosion COMMENTS ON MANAGEMENT PRACTICES - During the 1960's the high slopes of the Eureka Dunes began attracting off road vehicle (ORV) enthusiasts. Because the access road reaches the dunes at their northern end, most ORV activity centered there or nearby (05). This northern end of the dunes is also where the populations of Oenothera avita ssp. eurekensis (Eureka Valley evening-primrose) are best developed (01,05,12). ORV use increased fairly rapidly through the mid-1970's on the Eureka Dunes (05) as it did throughout much of California's desert regions. During this time such ORV activity was unrestricted and constituted a serious threat to the plants and animals of the Eureka Dunes ecosystem (03,05,13). Oe. a. ssp. eurekensis plants were run over and crushed as the lower dune slopes and sandy borders were used heavily for vehicle staging and camping areas and as vehicles moved from one area of the dunes to another. A serious possibility was that increasing impact could effect sand strength and result in increased wind erosion with unknown consequences (03,10) - possibly changing the character of the dunes. This serious ORV impact to the plants and to their habitat was of special concern because of the very restricted distribution of this subspecies and the relatively small known population. Little is known of the genetic diversity within this rare subspecies, possibly a low gene pool may already exist. The population biology of Oe. a. ssp. eurekensis remains virtually unknown (10). In the fall of 1976 the dunes were closed to ORV use (03,05,10, 12). Since that official closure, vehicle trespasses have occurred on a regular basis with some major violations occurring in 1978 and 1979 (02,04,05,06,12). Apparently in the 1980's enforcement has been more evident and only sporadic ORV activity has taken place (05,12). APPROVED PLAN: U.S. Fish and Wildlife Service. 1982. Eureka Valley Dunes Recovery Plan. U.S. Fish and Wildlife Service, Portland, OR. 80 pp. In order for the Eureka Valley evening-primrose to survive and Management Practices - 1 (DRAFT) - Management Practices Species EVENING-PRIMROSE, EUREKA VALLEY Species Id ESIS701024 Date 13 MAR 96 flourish, threatening impacts such as detrimental and indiscriminate ORV use and excessive human intrusion into the dune habitat, must be reduced, and, if possible, eliminated. Protection and management of the Eureka Dunes is therefore imperative. Closure of Eureka Dunes to all ORV use must be maintained and enforced. Clear communication of legal restrictions, accompanied by adequate enforcement, will greatly assist in the recovery of this species. Restrictions should include confining all vehicles to designated roads, and prohibiting camping on dune slopes and borders. Research on the Eureka Valley evening-primrose and dune area should be encouraged to further protect this species. The dunes were closed to all ORV activities in 1976. Since the closure, seedlings have appeared in ecologically damaged areas. Signs have been erected, and law enforcement patrols have been initiated. It has not been considered necessary to transplant or seed areas or otherwise supplement the natural reproductive processes at this time. Management Practices - 2
                                   (DRAFT) - References
                         Species EVENING-PRIMROSE, EUREKA VALLEY
                                  Species Id ESIS701024
                                      Date 13 MAR 96



     

References

***** REFERENCES FOR ALL NARRATIVES EXCEPT N-OCCURRENCE ***** 01 Bagley, M. 1986. Baseline data for a sensitive plant monitoring study on the Eureka Valley Dunes, Inyo County, California. Bur. of Land Mgmt, Riverside, CA, BLM Contract No. CA-065-R04-61. 104 pp. 02 DeDecker, M. 1976. The Eureka Dunes. Fremontia 3:17-20. 03 DeDecker, M. 1977. California Native Plant Society Rare Plant Status Report: Oenothera avita ssp. eurekensis. CA Native Plant Soc., Sacramento, CA. 4 pp. 04 DeDecker, M. 1979. Can BLM protect the dunes? Fremontia 7:6-8. 05 DeDecker, M. 1982. Eureka Valley Dunes recovery plan. U.S. Fish and Wildl. Serv., Portland, OR. 80 pp. 06 Henry, M.A. 1979. A rare grass on the Eureka Dunes. Fremontia 7:3-6. 07 Klein, W.M. 1962. New taxa and recombinations in Oenothera (Anogra). Aliso 5:179-180. 08 Klein, W.M. 1965. In treatment of Onagraceae by P.A. Munz for N. Amer. Flora, ser. 2, pt. 5:1-231 (see p. 116). 09 Munz, P.A. and J.C. Roos. 1955. California miscellany--III. Aliso 3:118-119. 10 Pavlik, B.M. 1979. The biology of endemic psammophytes, Eureka Valley, California, and its relation to off-road vehicle impact. CA Desert Plan, BLM Contract No. CA-060-CT8-000049. 110 pp. 11 Pavlik, B.M. and M.G. Barbour. 1985. Demography of endemic psammophytes, Eureka Valley, California, I. Seed production, dispersal and herbivory. CA Fish and Game, Endangered Plant Prog., Sacramento. 77 pp. 12 Rowlands, P.G. 1982. Physical and biotic attributes of the Eureka Dunes Region, Eureka Valley, California. Unpubl. rept. submitted to BLM, CA Desert Dist. Library, Riverside, CA. 13 U.S. Fish and Wildlife Service. 1978. Determination that various plant taxa are endangered or threatened species. Fed. Reg. 43(81): 17910-17916. ***** REFERENCES FOR N-OCCURRENCE NARRATIVE ONLY ***** 01 Bagley, M. 1986. Baseline data for a sensitive plant monitoring study on the Eureka Valley Dunes, Inyo County, California. U.S. Bur. of Land Mgmt., Riverside, CA, BLM Contract No. CA-065-R04-61. 104 pp. 02 Bagley, M. 1986. Unpublished field notes from May 29-30 survey of Marble Canyon Dunes and Saline Spur Dunes, Eureka Valley, CA., U.S. Bur. of Land Mgmt., Riverside, CA. 03 DeDecker, M. 1982. Eureka Valley Dunes recovery plan. U.S. Fish and Wildl. Serv., Portland, OR. 80 pp. 04 Pavlik, B.M. 1979. The biology of endemic psammophytes, Eureka Valley, California, and its relation to off-road vehicle impact. CA Desert Plan, BLM Contract No. CA-060-CT8-000049. 110 pp. 05 Rowlands, P.G. 1982. Physical and biotic attributes of the Eureka Dunes region, Eureka Valley, California. Unpubl. rept. submitted References - 1 (DRAFT) - References Species EVENING-PRIMROSE, EUREKA VALLEY Species Id ESIS701024 Date 13 MAR 96 to BLM, CA Desert Dist. Library, Riverside. References - 2