Forty-two mosses and three liverworts are reported as new for Nevada. The genera Amblyodon, Campyliadelphus, Isopterygiopsis, Mesoptychia, Myurella, Plagiobryoides, Plagiobryum, Platydictya, Pseudocampylium, and Preissia are new for the state of Nevada. Splachnobryum obtusum and Pseudoleskeella rupestris are now confirmed for Nevada based on recently collected material. Grimmia texicana is excluded from the Nevada checklist based on a herbarium label locality error. The bryoflora of Nevada with 355 taxa is comprised of two hornworts, 49 liverworts, and 304 mosses.

Eremocarya (Boraginaceae), a recently resurrected segregate of the genus Cryptantha, has generally been recognized as containing a single species, E. micrantha, with two varieties. Here we present evidence that these two varieties are distinct in a number of features and that they should be treated as separate species: Eremocarya lepida and E. micrantha. Eremocarya lepida differs from E. micrantha in having a significantly greater corolla limb width, nutlet length, maximum nutlet width, and maximum nutlet width: apical nutlet width. Eremocarya lepida also has prominent yellow fornices near the apex of the corolla throat, whereas fornices are absent and the fornix region lacks pigmentation in E. micrantha. In addition, we report the discovery of clusters of minute (ca. 0.1 mm long), transparent, stalked, ellipsoid structures born near the apex of the inner corolla tube that are associated with the five corolla fornices, these being unique to E. lepida. These structures, which we term “fornix bodies,” are of unknown chemistry and function, but they may possibly have a role in the pollination of the showier, larger-flowered E. lepida. In addition to these morphological characters, the two species differ in distribution, elevation, and plant community/vegetation. Eremocarya lepida occurs at higher elevation in chaparral, coniferous woodland, and high desert scrub of southern California and northern Baja California, México. Eremocarya micrantha occurs at lower elevations in desert habitats of Arizona, California, New Mexico, Texas, Oregon, and Utah in the United States, and Baja California and Sonora in México. All of these data strongly support recognition of two species in Eremocarya.

Ceanothus otayensis McMinn (Rhamnaceae) was previously known only from metavolcanic-derived soils of the northern Peninsular Ranges—predominantly the San Ysidro Mountains—in San Diego County, California, and adjacent Baja California, Mexico. Recently, a new population of C. otayensis was discovered on sedimentary soils at Marine Corps Air Station Miramar, 25 km northwest of the next nearest known population. Sedimentary deposits at the new locality are thought to produce unusual soils. It is possible that the disjunct distribution of C. otayensis is a response to soil conditions, a phenomenon frequently seen in other members of Ceanothus, for instance on serpentine. The present study uses soil chemistry data for seven populations and subpopulations of C. otayensis (metavolcanic: n  =  5; sedimentary: n  =  2), as well as 22 populations of closely related Ceanothus, to determine whether soils of C. otayensis are chemically distinct from those of closely related Ceanothus, and answer the following question: are sedimentary-derived soils at the new locality chemically similar to metavolcanic-derived soils that support all other known populations of the species? Soils of C. otayensis proved to be chemically distinct from soils of closely related Ceanothus, with significantly lower levels of nitrate, sulfur, and conductivity. Sedimentary and metavolcanic soils of C. otayensis proved to be chemically indistinguishable from one another (P < 0.05), with low levels of all assayed nutrients other than Ca, suggesting a chemical similarity among the soils of C. otayensis that may help explain its disjunct distribution. Population size estimates indicate that the new disjunct locality at Marine Corps Air Station Miramar supports about 75 adult individuals.

Coreopsis tinctoria (coreopsis, calliopsis, plains coreopsis, or golden wave) is an annual herbaceous Asteraceae with a broad geographic distribution mostly in the central and western United States. It co-occurs with Bouteloua curtipendula (sideoats grama) or other native C₄ grasses. When grown together, C. tinctoria response variables decreased significantly in the presence of B. curtipendula aboveground, belowground, and total dry mass. The response variables included mean plant height, number of flower buds per plant, flowers per plant, as well as aboveground, belowground, and total dry mass. The presence of B. curtipendula belowground dry mass caused the greatest suppression of C. tinctoria belowground dry mass. When B. curtipendula tops were clipped to reduce grass aboveground dry mass (simulated herbivory), the percent survival of C. tinctoria plants increased from one percent in the no-clipping treatment to 18% in the neighbor removal treatment (100% clipped). Coreopsis tinctoria does not appear to be a good competitor in the presence of B. curtipendula and seems to be restricted to gaps or patches in disturbed grasslands where competition from perennial grass neighbors is reduced.

Carex xerophila Janeway & Zika is described from gabbro and serpentine soils on the west slope of the northern Sierra Nevada in California. It is documented from four populations in or on the margins of chaparral and open forest. The new species is assigned to Carex section Acrocystis Dumort., and a key is provided for all California representatives of the section. Carex xerophila differs from C. globosa Boott in its uniformly short, erect basal peduncles and Sierra foothills habitats. Carex xerophila differs from C. brainerdii Mack. by its green leaves that are not densely papillose below, its relatively shorter perigynium beaks, and its lower elevation montane habitats. Carex xerophila has more strongly nerved scales and perigynium faces than C. rossii Boott.

I report a new species of Nemophila growing sympatrically in some localities with N. menziesii Hook. & Arn. var. atomaria (Fisch. & Mey.) H. P. Chandler (sensu Constance 1941) in Northern California. The new species, N. hoplandensis, differs from N. menziesii var. atomaria in both floral and vegetative color. The corollas of N. menziesii var. atomaria range from deep blue to a bluish white. Nemophila hoplandensis has large and unusually bright white corollas and vegetative structures that are a brighter green than those of N. menziesii var. atomaria. I provide support from controlled crosses for treating these populations as a new species; despite sharing pollinators N. hoplandensis is reproductively isolated from N. menziesii var. atomaria via failure of hybrid seed production following artificial crosses. Molecular phylogenetic analyses also clearly differentiate N. hoplandensis within the genus. The newly described species, currently known only from Mendocino and Napa counties, has a range that is more restricted than and lies within the range of N. menziesii var. atomaria.