Obligate seeding plants—those that are killed by fire and whose persistence depends on soil-stored seedbanks—may be particularly susceptible to indirect effects of habitat loss and fragmentation. Especially for rare species, fragmentation can create conditions that reduce the likelihood of achieving sufficient seed bank stores due to changes in the interactions of the remaining plants with their pollinators or their natural enemies such as herbivores or seed predators. Arctostaphylos morroensis (Morro Manzanita) is an endemic obligate seeder whose distribution has been reduced greatly to a small portion of coastal California in habitat that is fragmented by development. We examined the reproductive ecology of A. morroensis to determine the factors that affect seed input to the soil seed bank. In stands of different ages and percent cover of Morro Manzanita, we observed insect pollinators, and measured flower and fruit production, and rates of fruit predation over two years, hypothesizing that, based on previous literature on obligate-seeders, fruit set should be relatively high across all stands, fruit set should be resource-limited, and seed input should be relatively high. Our observations suggest that A. morroensis reproduction is dependent on pollinators, which were primarily bees. Contrary to our predictions, we found that fruit set was relatively low (averaging 10–18% over both years) at all stands and appears to be pollinator-limited. Fruit predation rates were high, with the majority of fruits in experimental trays removed in a matter of weeks. We suspect that seed input in this rare species is strongly limited by low fruit set and high seed predation.

California's central coast contains high species richness and plant endemism that is threatened by ongoing land use and climate change. Better understanding of regional vegetation dynamics is needed, where its vegetation mosaic and stand succession interact with a strong Mediterranean climate, wildfire, and grazing. We examined what historical data could reveal about these interactions by using two lines of evidence—historical aerial photographs from 1938 and vegetation maps surveyed in the 1930s—and comparing them to other photographs and maps up to 2015. We used the recently established Jack and Laura Dangermond Preserve as the study area. The Preserve, stretching from the coast near Point Conception to the Santa Ynez Mountains, encompasses chaparral, grassland, oak woodlands, coastal scrub and closed-cone pine vegetation types. We asked what long-term vegetation change has occurred, and if we could detect the influences of wildfire frequency and grazing pressure. Across the 80-year time period, we found that grassland cover decreased by 26%, while shrubland and oak woodland cover increased by 31% and 16%, respectively. Our results were consistent across both historic datasets, lending confidence to the trends observed over time. These trends are consistent with other similar analyses along coastal California, supporting the long-held hypothesis that coastal grassland communities, and their unique biodiversity values, are lost as grazing and fire decrease. Our results motivate future work on the restoration of native grassland species and point to the possibility of using designed spatial patterns of coastal California vegetation mosaics to preserve long term habitat dynamics for the region's native plant communities in this biodiversity hotspot.

A common belief of many hikers and naturalists is that smooth-barked species like Arbutus menziesii Pursh (Pacific Madrone, Ericaceae) have bark that is colder than the air temperature. Beliefs like this draw upon specific experiences people have after comparing different species. Natural history has a ‘history’ of stories like this that sometimes can misinform. The incorrect myths are not usually problematic, but there are instances of natural history myths that can influence policy decisions. The philosophy of science is to test theories and their assumptions; this study tests the pervasive ‘fact’ that species with especially smooth bark, specifically Arbutus menziesii and Arctostaphylos Adans. (Ericaceae) species in California, have substantially cooler bark than other species or the air temperature. When tested, however, results showed bark temperature did not differ from air temperatures among species on shaded stems, while on sunny stems temperatures differentially increased based on the relative color of the stem. Two experiments were conducted to test the human perception that smooth bark is cooler than other stems: (1) a test of the hypothesis that bark temperature is caused by xylem water cooling the stem, and (2) a surface-area experiment to test whether the perception is due to thermal conductance from hands to stem. Xylem-water cooling received no support, but surface-contact thermal conductance did. Perceptions of cold bark in smooth-barked species have persisted because only plant processes were considered, rather than the simple physics involved.

We have re-located the presumed type population of Potentilla millefolia Rydb. var. algida Jeps. (Rosaceae), an ambiguous cinquefoil from the high Trinity Alps of California previously known to Western science only from Harvey Monroe Hall's original collection in 1909. Based on the totality of morphological and ecogeographical evidence, we conclude that this plant represents a valid taxon that bears more resemblance to P. versicolor Rydb. than to P. millefolia s. s., and which is furthermore more appropriately treated at the species level. Since the combination P. algida Soják is already taken, we propose the replacement name P. norrelmukana DiNicola & Ertter, after the Nor Rel Muk Wintu people to whose land the taxon is endemic, and the English common name “Nor Rel Muk Cinquefoil.” This resurrection adds a new rare species to the California flora.

A new Ranunculus species, Ranunculus basalticus Giblin sp. nov., is described from sagebrush-steppe and low elevation grassland areas of south-central Washington. The species is close in appearance to two sympatric Ranunculus species, the narrow endemic R. triternatus A.Gray and the broadly distributed R. glaberrimus Hook. However, discrete morphological, ecological, and distribution differences easily separate R. basalticus from these other species. The earliest record of R. basalticus dates to 2004 in the form of a digital photo, with subsequent voucher specimens first collected in 2009. Additional field collecting, along with photo submissions to iNaturalist, suggest that R. basalticus is a narrow endemic of Kittitas, Klickitat, and Yakima counties in Washington. It most commonly occurs in soil-stabilized basalt talus, for which the specific epithet refers. Although R. basalticus appears to have a narrow distribution, within its range, population sizes can exceed 100 plants. All currently documented populations are on public lands managed for multiple uses, though there appear to be no direct threats to these populations.

Horkelia tridentata Torr. var. illiterata Ertter & Reveal is proposed for aberrant populations clustered in the southeast margin of the species' range in the High North Coast Ranges in California. The variety has most of the diagnostic characters of var. flavescens (Rydb.) Ertter & Reveal, which is otherwise the only variety in the North Coast Ranges, but lacks the hairs on the interior wall of the hypanthium that provide the most reliable distinction between var. flavescens and var. tridentata; the epithet indicates a classic example of plants that “haven't read the book.” This is the only variety of H. tridentata that occurs in and near the Berryessa Snow Mountain National Monument. The relatively few populations indicate that some level of conservation status is warranted.