The Claytonia sibirica complex, including C. sibirica and C. palustris, exhibits considerable morphological variation that encompasses ecological diversity over a wide geographic range. Shoots are basically rhizomatous in the complex and least specialized in C. sibirica var. sibirica. Claytonia sibirica var. bulbillifera, a serpentine endemic of southern Oregon and northern California, forms succulent, storage scale leaves distal to its foliage leaves each growing season. These scale leaves, which consist primarily of leaf base, are generally lacking in other members of the sibirica complex and give the shoot systems of C. sibirica var. bulbillifera a bulb morphology. Claytonia palustris, like C. sibirica var. sibirica, forms an apically swollen rhizome, but differs in its habit by forming renewal shoots, born in the axils of the basal leaves, at the ends of plagiotropic, single long internodes.

Most populations of Salvia pachyphylla occur along mountain ranges adjacent to the Mojave Desert of southern California, southwestern Nevada, and northern Baja California, Mexico. A smaller disjunct group occurs in eastern Arizona near the southern edge of Navajo and Hopi reservation lands near Winslow, AZ. This study was undertaken to determine whether there are morphologically and genetically distinct geographical groups within S. pachyphylla and whether these groups form a cohesive unit easily separated from S. dorrii. Specimens of S. pachyphylla and broadly sympatric taxa in S. dorrii were examined in a morphometric analysis of twelve characters. A preliminary molecular analysis using the nuclear ribosomal DNA internal transcribed spacers (ITS-1 and ITS-2) and the embedded 5.8 S subunit was also performed on the same taxa. Morphometric analysis supports the continued recognition of S. pachyphylla and S. dorrii as distinct species and the recognition of three subspecies within S. pachyphylla, requiring two new subspecies, eremopictus and meridionalis, described here. The molecular data support the recognition of the S. dorrii species complex as a whole, but do not support the separation of S. dorrii and S. pachyphylla as distinct species, although the Mexican populations of S. pachyphylla appear genetically distinct.

Prior molecular work using ITS and chloroplast sequence data revealed that the endemic Lithophragma trifoliatum and the broad-ranging L. parviflorum form a tight clade with a third species, L. affine. We used AFLPs to assess the fine scale relationship of these three species from populations where their distributions overlap in northern California. Our results revealed two groups of L. trifoliatum, one nested within a group of L. affine and L. parviflorum and the other grouped with other populations of L. parviflorum, contrary to predictions based on plant morphology alone. The morphological pattern was not supported by the molecular data, suggesting that pink flowers evolved more than once, concurrently with other floral traits such as size and nectary length. It is also possible that this pattern is due to recent evolution or gene flow between the two color morphs. The possible ecological importance of these differences in floral traits (e.g., for pollination) warrants further study, as well as the extent to which these populations are reproductively isolated.

During a three-year botanical inventory of the Hanford Nuclear Reservation in south-central Washington, we located three previously undescribed entities (Astragalus conjunctus S. Watson var. rickardii Welsh, K.A. Beck, and Caplow, Eriogonum codium Reveal, Caplow, and K.A. Beck, and Physaria douglasii (S. Watson) O'Kane and Al-Shehbaz subsp. tuplashensis (Rollins, K.A. Beck, and Caplow) O'Kane and Al-Shehbaz, four species new to Washington (Cistanthe rosea (S.Watson) Hershk., Gilia leptomeria A. Gray, Loeflingia squarrosa Nutt., and Myosurus clavicaulis M.E. Peck), and one previously described species that had generally gone unnoticed by the American botanical community (Festuca washingtonica E.B. Alexeev). The botanical inventory was a part of the Hanford Biodiversity Project, which was funded by the Department of Energy and administered by The Nature Conservancy of Washington.

A review of taxonomic literature, examination of existing herbarium specimens, and a morphological study of field-collected material demonstrates that species circumscriptions have been misapplied for the small-flowered Brodiaea species with spreading perianth lobes and floral tubes narrowed above the ovary. The results of these studies demonstrate that Niehaus's (1971) concept of B. purdyi, polyploid plants that occur in woodland habitats in the northern Sierra Nevada foothills, applies to the taxon originally described as B. minor, placing B. purdyi in synonymy with B. minor. Niehaus's concept of B. minor, diploid plants occurring in vernal pool terrain, applies only to those populations originally described as Brodiaea nana, which is resurrected at species rank.

Coastal sage scrub (CSS) is a target for restoration because it provides habitat for numerous special-status species and it has been impacted by urbanization, agriculture and invasion by non-native species. Many restoration designs have neglected the herbaceous understory component of CSS, although it may comprise the majority of vascular plant species in a natural CSS stand. The omission of an understory may promote invasion by non-native plants and reduce overall success. This study investigated the role of native seed addition, non-native species removal, gaps in the shrub canopy, and soil moisture, upon establishment of a native understory. Native biomass increased significantly with seed addition, and the abundance of experimentally seeded native species was positively correlated with soil moisture. Natives were not affected by competition with non-natives or the presence of gaps. Although all seeded native species germinated, only two of seven established successfully, perhaps due to very low rainfall. Non-native species were negatively affected by the addition of native seeds and had greater growth in gaps. We conclude that planting shrubs in a dense configuration to reduce gap size may reduce non-native species abundance in the understory while having little effect on the native understory. Seeding may be all that is required to establish a native understory, and may also be an effective method of suppressing non-native species.

Frond growth and development of Pentagramma triangularis subsp. triangularis was examined in canyon populations in Ventura County, California during the winter growing season of 2003. Fronds developed from emerging croziers to full size within 35 days and reached sexual maturity by 70 days. Frond growth occured in two stages with stipe elongation nearly complete when the crozier began to unfurl, about a week before full maturation of the entire frond. Discernable developmental stages are described as well as their respective ages. Fern growth occurred both prior to and after the study frond monitoring period, indicating multiple growth flushes throughout the growing season, possibly related to rain events. Based on these preliminary results, suggestions are offered for further study.

Following our recent discovery of seven new Shasta snow-wreath populations during 2003 and 2004, we conducted a GIS analysis using location data from the new sites, and from all previously known sites to determine the habitat, geologic, and soil characteristics of each Shasta snow-wreath population location. Previously considered a species only associated with limestone substrates, our new information shows that 47% of all known Shasta snow-wreath sites occur on non-limestone geologic or soil types.

Additional measurements of male and female plants and staminate flowers are reported for Arceuthobium pendens. Measurements for fruits and seeds of this rare mistletoe are reported for the first time. Additional information on phenology and host reactions to infection is reported also.

Silene salmonacea T.W. Nelson, J. P. Nelson and S.A. Erwin is here described as new and illustrated; endemic to the Klamath Mountains of Shasta -Trinity National Forest west of Clair Engle Lake. Silene salmonacea is compared with Silene hookeri Nutt. and Silene bolanderi A. Gray. A key to the three members of the S. hookeri complex is included.

Lepechinia rossii (Lamiaceae) is described as a new species narrowly endemic to the western Transverse Ranges of southern California. It is a member of section Calycinae, which includes four additional species endemic to California and adjacent Baja California, Mexico—L. calycina, L. cardiophylla, L. fragrans, L. ganderi—and L. mexicana, an anomalous, and probably unrelated, species from central Mexico. Lepechinia rossii is most readily distinguished from other members of section Calycinae by geniculate inflorescence axes, bent at 60–90° angles relative to the subtending stems, and by large, foliaceous inflorescence bracts which are generally equaling or exceeding their adjacent flowers in length, and little reduced distally. At present, two populations are documented, one in the Liebre Mountains (Los Angeles County) and one in the Topatopa Mountains (Ventura County), both occurring in chaparral, on public lands administered by the U.S. Forest Service. Conservation concerns include habitat degradation by off-highway vehicle activity, power line maintenance, petroleum exploration and extraction, and anthropogenic changes in fire frequency.