Low elevation grasslands in California long have been dominated by Mediterranean grasses, but many areas still have large native forb populations. Alien forbs invade these grasslands, displacing both native and other alien species. Italian thistle is a noxious alien herb that has recently invaded these grasslands, including ungrazed blue oak (Quercus douglassii) and interior live oak (Quercus wislizenii) stands in Sequoia National Park. Here, Italian thistle tends to dominate under oaks and has the potential to substantially alter the foothill ecosystem by displacing native plants and acting as a ladder fuel that can carry fires into the oak canopy. We tested the effects of selectively reducing Italian thistle populations alone and in combination with restoration of native species. Two thistle eradication techniques (clipping and the application of clopyralid herbicide) and two restoration techniques (addition of native forb seeds or planting native grass plugs) were used. After two consecutive years of treatment we found: a) clipping was not effective at reducing Italian thistle populations (clipping reduced Italian thistle density in some areas, but not vegetative cover), b) herbicide reduced both Italian thistle density and vegetative cover for the first two growing seasons after application, but cover rebounded in the third growing season, c) native forb cover and species richness were not significantly affected by clipping or spot-treating with herbicide, d) the grass and forb addition treatments by themselves were not effective at reducing Italian thistle during the course of this study and e) sowing annual forb seeds after clipping resulted in greater forb cover and moderately reduced Italian thistle vegetative cover in the short term.

The taxonomically difficult and ecologically and phytogeographically important genus, Calamagrostis, was examined for British Columbia (BC). Morphological characters were analyzed by Principal Components Analysis (PCA) to characterize taxa and to aid in the development of a new key. Eight native species (Calamagrostis canadensis, C. lapponica, C. montanensis, C. nutkaensis, C. purpurascens, C. rubescens, C. sesquiflora, and C. stricta) are confirmed to occur in British Columbia, of which C. montanensis, C. nutkaensis, C. purpurascens, C. rubescens, and C. sesquiflora are reliably distinguishable. Comparison of species distribution to regional climatic and vegetation history suggests that Calamagrostis nutkaensis and C. sesquiflora likely survived in coastal refugia during late Wisconsin glaciations. Calamagrostis purpurascens likely persisted beyond the glacial limits or within nunataks and then spread into previously glaciated sites. Two interior continental species, C. montanensis and C. rubescens, probably spread north and west from the unglaciated zone south of the Cordilleran and Laurentide ice sheets. Calamagrostis lapponica likely persisted north of the ice sheets, and then spread southward into high-elevation sites in northern and eastern BC. Calamagrostis canadensis and C. stricta probably survived south and north of the ice sheets, and then spread into the previously glaciated terrain.

Foxtail pine, Pinus balfouriana Grev. & Balf., is an endemic subalpine conifer of California with two allopatric subspecies. The northern subspecies grows in northwestern California and the southern subspecies is found in the southern Sierra Nevada. We studied three northern and three southern populations of P. balfouriana to evaluate the population biology, demography, mortality agents, and environmental conditions in these contrasting regions. Northern populations exist under a mesic climatic regime, a diversity of geological substrates, stands of high tree species richness, lower densities and basal areas, but higher numbers of recruitment, with a relatively mixed size class distribution. Southern foxtail pine populations exist under a xeric climatic regime dominated by granitic substrates, with moderate to high stand densities, less tree species-rich, lower recruitment numbers, but higher basal areas; due to a skewed size class distribution with high representation of large diameter trees. Recruitment in the north averaged 169.3 seedlings/saplings ha⁻¹, compared to 91.3 seedlings/saplings ha⁻¹ in the south, despite the fact that northern populations produce less cones on average (3695 cones ha⁻¹) than populations in the southern Sierra Nevada (7642 cones ha⁻¹). At the stand-level, solar radiation input and foxtail pine density were correlated with fecundity. These factors may correspond with microenvironmental and topographic conditions that favor germination (e.g., warmer microclimate) and propagule pressure (e.g., seed supply). At the local or plot-level, microenvironmental conditions (e.g., litter, substrate type, and microhabitat) and factors corresponding to local seed supply (e.g., density, basal area, number of cones, and number of reproductive adults) were correlated with recruitment, particularly in the southern Sierra Nevada. Foxtail pine is recruiting episodically in higher numbers in the north and lower numbers in the south. Four of six populations appear to be stable, due to low mortality and high survivorship. Low estimates of population growth (λ) at Lake Mountain (north) and Sirretta Peak (south) were due to mortality of large diameter trees and low recruitment. At these locations, mountain pine beetle-mediated mortality and drought stress appear to be important factors contributing to current population trends.

Garrya (Garryaceae) comprises 15 species of shrubs and small trees restricted to the Americas. Garrya is taxonomically divided into two subgenera, Garrya and Fadyenia, which differ in morphology, secondary chemistry, and geographic distribution. The present work uses nuclear ribosomal DNA (ITS) sequence data from 11 Garrya species to elucidate phylogenetic relationships within the genus and test the monophyly of the subgenera. Results strongly support subgenus Fadyenia as monophyletic, while monophyly of subgenus Garrya is supported only by maximum parsimony analyses. ITS data do not provide evidence for genetic admixture between the two subgenera of Garrya in spite of broad geographic overlap.

The holotype of Arctostaphylos hooveri P. V. Wells, cited as having been deposited in the Robert F. Hoover Herbarium, California Polytechnic State University (OBI), apparently is not extant. The isotype deposited in the University Herbarium (UC) at the University of California, Berkeley (Hoover & Wells 1960 — UC 1218855) is designated as the lectotype, and the isotype in the California Academy of Science Herbarium (CAS 423565) is thereby an isolectotype. Hoover 8520 (OBI 175682) is recognized as a paratype.

Calyptridium parryi var. martirense is described as new. Here we present quantitative measurements and statistical analyses of a number of morphological features that demonstrate the distinctiveness of this new taxon. The new variety differs from the others in having shorter fruits (3.1–4.1 mm) and a correspondingly smaller fruit length to sepal length ratio (1.0–1.4). The capsule is also the widest (1.4–2.2 mm) and the sepals the longest (2.4–3.9 mm) of any other C. parryi variety. Calyptridium parryi var. martirense is currently known only from high elevation locations (1900–2630 m) in the Sierra de San Pedro Mártir, Baja California, Mexico.

The following nomenclatural combinations in Phacelia (Boraginaceae) are established: P. campanularia A. Gray var. vasiformis (G. W. Gillett) Walden & R. Patterson, stat. nov.; P. imbricata Greene var. bernardina (Greene) Walden & R. Patterson, stat. nov.; P. imbricata Greene var. patula (Greene) Walden & R. Patterson, stat. nov.; and P. nemoralis Greene var. oregonensis (Heckard) Walden & R. Patterson, stat. nov. Typification and clarification of nomenclature is provided for Phacelia floribunda Greene and Phacelia phyllomanica A. Gray. Synonymies are provided for all names.