Mediterranean-type climate California experiences both frequent wildfires and periodic drought. Climate change models predict increased severity of drought, and wildfire size and frequency, leading to concern about the ability of some plant species to recover to pre-fire conditions when wildfires and drought coincide. During exceptional drought, drought-adapted native vegetation, such as perennial native grassland, can experience substantial die-off. Here we use three post-fire case studies in southern California to assess the combined effects of fire and drought on the resilience of a native perennial bunchgrass, Stipa pulchra Hitchc. (Poaceae). We hypothesized that resilience to fire, assessed as post-fire survival, resprouting and fecundity (i.e., number of flowering plants and inflorescences), would decrease if the fire occurred during a drought. Unburned (control) sites had about double the survival and resprouting, and about three times the fecundity compared to moderate-severity burn sites. Resprouting and fecundity in the low-severity burn sites was about twice that of moderate-severity burn sites, and survival was five times higher. Responses to two springtime fires that occurred during drought were similar (average mortality 37%), in contrast to a fall fire with no drought (6%). We cannot separate the relative contribution of drought effects from those of the time of year (spring vs. fall), burn severity, and other site factors. However, moderate-severity burns, in combination with drought, decreased survival, resprouting, and fecundity of S. pulchra.

Herein I present the description of two new species, Streptanthus medeirosii N.Jensen from the Tehachapi Mountains in Kern County, and S. juneae N.Jensen from the San Bernardino Mountains in San Bernardino County, each described based on phylogenetic, morphological, geographical, and ecological evidence. In order to distinguish S. medeirosii and S. juneae from similar species, I provide diagnoses, a table comparing morphological characters, a taxonomic key, and maps showing their geographic ranges. To enable these comparisons, I also designate lectotypes for two closely related species, S. bernardinus (Greene) Parish and S. campestris S.Watson.

In the course of preparing the treatment of Nemacladus (Campanulaceae, Nemacladoideae) for Volume 18 of Flora of North America north of Mexico, it has become apparent that several new taxa must be described and others recircumscribed. These are: two new species of uncertain affinities from the White Mountains and Inyo Mountains; in the N. longiflorus A.Gray group, a new species and a variety elevated to species; four new species in the N. sigmoideus/N. secundiflorus complex; and a new variety of Nemacladus twisselmannii J.T.Howell.