California Flora Research Articles

Grimmia shevockii and G. insolita, two new species endemic to California

ABSTRACT Introduction California is a biodiversity hotspot for bryophytes, and its northern counties are among the most endemic-rich areas for bryophytes in North America. Having 29 species in California, Grimmia Hedw. is the third richest moss genus in the state, but recent fieldwork suggests that this number is an underestimate. The identity of some specimens endemic to the Klamath Mountains of California and previously identified as G. brevirostris R.S.Williams remains unclear, and they potentially represent a new species. Two further specimens of Grimmia from Siskiyou County, California, do not correspond to any species described so far. Here we present morphological and phylogenetic arguments for recognising these plants as two new moss species in the genus Grimmia subg. Orthogrimmia Schimp. Methods Morphological characters across potential new species were reviewed and compared with those of related species. Phylogenetic analyses based on the plastid trnS–trnF and nuclear ITS regions were conducted. Key results and conclusions The molecular and morphological analyses revealed two new species of Grimmia for California, which are described and illustrated: G. shevockii J.Muñoz, I.Solano & D.Quandt and G. insolita J.Muñoz, I.Solano & D.Quandt. The former is resolved in a monophyletic clade with high support, whereas the latter has incongruent positions in the plastid and nuclear phylogenies, thus it is hypothesised that it could have a hybrid origin. Both of the two new species and G. hamulosa undoubtly pertain to Grimmia. The richness of the bryophyte flora of California provides a clear warrant for future research.

Variation in Leaf Reflectance Spectra Across the California Flora Partitioned by Evolutionary History, Geographic Origin, and Deep Time

AbstractEvolutionary relatedness underlies patterns of functional diversity in the natural world. Hyperspectral remote sensing has the potential to detect these patterns in plants through inherited patterns of leaf reflectance spectra. We collected leaf reflectance data across the California flora from plants grown in a common garden. Regions of the reflectance spectra vary in the depth and strength of phylogenetic signal. We also show that these differences are much greater than variation due to the geographic origin of the plant. At the phylogenetic extent of the California flora, spectral variation explained by the combination of ecotypic variation (divergent evolution) and convergent evolution of disparate lineages was minimal (3%–7%) but statistically significant. Interestingly, at the extent of a single genus (Arctostaphylos) no unique variation could be attributed to geographic origin. However, up to 18% of the spectral variation among Arctostaphylos individuals was shared between phylogeny and intraspecific variation stemming from ecotypic differences (i.e., geographic origin). Future studies could conduct more structured experiments (e.g., transplants or observations along environmental gradients) to disentangle these sources of variation and include other intraspecific variation (e.g., plasticity). We constrain broad‐scale spectral variability due to ecotypic sources, providing further support for the idea that phylogenetic clusters of species might be detectable through remote sensing. Phylogenetic clusters could represent a valuable dimension of biodiversity monitoring and detection.

A FLORISTIC STUDY OF SWANTON PACIFIC RANCH, SANTA CRUZ COUNTY, CALIFORNIA

The Swanton Pacific Ranch (SPR) is located north of the town of Davenport, in Santa Cruz County, California, and is owned by California Polytechnic State University, San Luis Obispo. SPR is approximately 1295 ha and contains areas of salt marsh, coastal prairie, coastal bluff scrub, northern coastal scrub, riparian forest, redwood forest, mixed evergreen forest, and chaparral. The property extends over an elevational gradient from 0 m to 420 m. In this study, we conducted a floristic inventory at SPR and documented 636 taxa. Between 2017 and 2019 we vouchered 547 taxa with 974 specimens. We were unable to locate 63 taxa that had been previously reported, 27 represented from historic collections and 36 represented by personal observations, but lacking vouchers. We relocated, but did not collect, 26 taxa known from previous collections. Overall, we documented 93 families at SPR, with Asteraceae, Poaceae, and Fabaceae having the most species, respectively. California rare taxa, listed by the California Native Plant Society, made up 2.5% of the flora (n = 18). Locally rare taxa made up 10% of the flora (n = 65). Non-native taxa made up 26% of the flora (n = 169). We vouchered one new taxon for Santa Cruz County, Senecio aphanactis Greene, which has a California Rare Plant Rank of 2B.2; documented a new occurrence of Hesperocyparis abramsiana (C.B.Wolf) Bartel var. abramsiana, a Federally Threatened conifer; and collected a form of Sanicula crassicaulis Poepp. Ex DC that we have published as a distinct variety. Overall, this relatively small coastal ranch contained approximately 10% of the flora of California. The 2020 CZU Lightning Complex Fire burned ca. 90% of SPR within a year of this study being completed. This opens the possibility for this study to be used as a baseline for future studies examining post-fire shifts in plant diversity at a landscape scale.

CaliPopGen: A genetic and life history database for the fauna and flora of California

CaliPopGen is a database of population genetic data for native and naturalized eukaryotic species in California, USA. It summarizes the published literature (1985–2020) for 5,453 unique populations with genetic data from more than 187,394 individuals and 448 species (513 species plus subspecies) across molecular markers including allozymes, RFLPs, mtDNA, microsatellites, nDNA, and SNPs. Terrestrial habitats accounted for the majority (46.4%) of the genetic data. Taxonomic groups with the greatest representation were Magnoliophyta (20.31%), Insecta (13.4%), and Actinopterygii (12.85%). CaliPopGen also reports life-history data for most included species to enable analyses of the drivers of genetic diversity across the state. The large number of populations and wide taxonomic breadth will facilitate explorations of ecological patterns and processes across the varied geography of California. CaliPopGen covers all terrestrial and marine ecoregions of California and has a greater density of species and georeferenced populations than any previously published population genetic database. It is thus uniquely suited to inform conservation management at the regional and state levels across taxonomic groups.

Loxopteroides weeksae gen. et sp. nov. (Anacardiaceae) samaras and associated foliage from the Eocene of western North America

An extinct kind of winged fruit found at several Eocene sites in California and Oregon, western USA, occurs in association with pinnately compound anacardiaceous leaves that have been called Rhus mixta. The samaras were previously treated along with isolated leaves from the Chalk Bluffs flora of California in an extinct sapindaceous genus, Thouiniopsis myricaefolia (Lesquereux) MacGinitie. However, the samaras are nonschizocarpic and hence readily distinguished from the mericarps of extant Sapindaceae such as Acer, Thouinia and Thouinidium. We reassign the fruits to Anacardiaceae and note similarity to the extant Neotropical genus Loxopterygium which differs, however, in the shape of the endocarp and placement of the style. Fruits of Loxopteroides weeksae gen. et sp. nov. co-occur with leaves of Rhus mixta at multiple localities in California and Oregon.

NOMENCLATURAL NOTES ON TWO WESTERN TRICHOSTEMA

Two species of Trichostema L. (Ajugoideae, Lamiaceae) from western states need nomenclatural clarification. Trichostema simulatum Jeps. occurs throughout northern California and southern Oregon. It was published by Willis Linn Jepson in his 1925 flora of California citing the type collection as “Klamathon, Copeland 3534, Type”. This is a conflation of the collector's name and the specimen number of the exsiccata West American Plants, in which the type specimen was distributed by C. F. Baker in 1903. Furthermore, an herbarium name, “Trichostema laetum Greene,” appears on most T. simulatum type material. This designation was never published and is a nomen nudum. Trichostema austromontanum F.H.Lewis occurs throughout the mountain ranges of southern California and Baja California. Originally published with two subspecies by Harlan Lewis in 1945, the three taxa have since been determined to be invalidly published because Lewis did not provide a species description, only subspecies descriptions. Herein, we provide a clarification on the type specimens of T. simulatum Jeps. as well as a valid publication of the species name T. austromontanum.

Genome-wide genetic variation coupled with demographic and ecological niche modeling of the dusky-footed woodrat (Neotoma fuscipes) reveal patterns of deep divergence and widespread Holocene expansion across northern California.

Understanding how species have responded to past climate change may help refine projections of how species and biotic communities will respond to future change. Here, we integrate estimates of genome-wide genetic variation with demographic and niche modeling to investigate the historical biogeography of an important ecological engineer: the dusky-footed woodrat, Neotoma fuscipes. We use RADseq to generate a genome-wide dataset for 71 individuals from across the geographic distribution of the species in California. We estimate population structure using several model-based methods and infer the demographic history of regional populations using a site frequency spectrum-based approach. Additionally, we use ecological niche modeling to infer current and past (Last Glacial Maximum) environmental suitability across the species' distribution. Finally, we estimate the directionality and possible spatial origins of regional population expansions. Our analyses indicate this species is subdivided into three regionally distinct populations, with the deepest divergence occurring ~1.7 million years ago across the modern-day San Francisco-Bay Delta region; a common biogeographic barrier for the flora and fauna of California. Our models of environmental suitability through time coincide with our estimates of population expansion, with relative long-term stability in the southern portion of the range, and more recent expansion into the northern end of the range. Our study illustrates how the integration of genome-wide data with spatial and demographic modeling can reveal the timing and spatial extent of historic events that determine patterns of biotic diversity and may help predict biotic response to future change.

AN UPDATED DATABASE OF SERPENTINE ENDEMISM IN THE CALIFORNIA FLORA

We update and revise the serpentine affinity database of Safford et al. (2005), which documents levels of plant taxon association with ultramafic (“serpentine”) substrates in the California flora. The revised database reflects recent taxonomic changes consistent with the second edition of the Jepson Manual (TJM2) and more recent updates to the Jepson eFlora, and includes additional species that were not previously documented as serpentine associates. We also include serpentine-associated species that have been described since the publication of TJM2 and are not yet incorporated in the eFlora. A number of taxa were removed from the Safford et al. (2005) database due to new ecological information or taxonomic changes. As before, the new database presents information on rarity, geographic distribution, taxonomy, and lifeform. Based on our new database numbers and TJM2's list of California endemic species, the percentage of California endemic full species that are +/– restricted to ultramafic substrates has risen to 14.7%. Of 255 total endemic taxa in our database (including strict and “broad” endemics), 148 (c. 60%) come from only ten plant families, concentrated mostly in one or two genera per family. The North Coast and Klamath Ranges continue to support more serpentine endemics than the rest of the State combined. The previous version of the database has been widely used in biodiversity research and conservation management, and we hope that this improved and updated version will prove as valuable.

Biology and native host range of the defoliating beetle Ageniosa cf. badenii (Chrysomelidae), a potential biological control agent for Cape ivy (Delairea odorata) in invaded countries

ABSTRACT Delairea odorata Lemaire, Cape ivy (Asteraceae: Senecioneae), is native to South Africa but invasive in several countries. The plant is a target for biological control in the USA (California and Hawaii) and Australia, where its aggressive smothering tendencies threaten native ecosystems. The beetle Ageniosa cf. badenii (Vogel) (Chrysomelidae) was investigated in South Africa as a potential agent for D. odorata in invaded countries. Adults are wingless and nocturnal. Females deposit clusters of 1–10 eggs on the leaf undersides. Neonate larvae are highly mobile and feed on the leaves during the four instars, before pupating in the soil. Mean (± SE) developmental time from egg hatch to adult emergence was 30.8 ± 0.4 days on D. odorata. During larval no-choice tests with 34 asteraceous plant species, survival to adulthood was confined to 10 species in the tribe Senecioneae. Neonate larvae completed development (with sustained fitness ≥ 65% in relation to the highest ranked host) on three native (Senecio tamoides DC., D. odorata and S. skirrhodon DC.) and one exotic (Gynura procumbens (Lour.) Merr.) species. The beetle’s narrow host range was confirmed by larval paired-choice and adult multi-choice tests and field observations. Ageniosa cf. badenii may be a suitable agent for Hawaii, where the tribe Senecioneae is not represented in the native flora. However, since Senecioneae are well represented in the native flora of Australia and California, more intensive testing is needed to determine if the beetle is a candidate for introduction into these areas.

Adaptation and divergence in edaphic specialists and generalists: serpentine soil endemics in the California flora occur in barer serpentine habitats with lower soil calcium levels than serpentine tolerators.

Adaptation to harsh edaphic substrates has repeatedly led to the evolution of edaphic specialists and generalists. Yet, it is unclear what factors promote specialization versus generalization. Here, we search for habitat use patterns associated with serpentine endemics (specialists) and serpentine tolerators (generalists) to indirectly test the hypothesis that trade-offs associated with serpentine adaptation promote specialization. We predict that (1) endemics have adapted to chemically harsher and more bare serpentine habitats than tolerators, and (2) edaphic endemics show more habitat divergence from their sister species than tolerators do among on- and off-serpentine populations. We selected 8 serpentine endemic and 9 serpentine tolerator species representing independent adaptation to serpentine. We characterized soil chemistry and microhabitat bareness from one serpentine taxon of each species and from a paired nonserpentine sister taxon, resulting in 8 endemic and 9 tolerator sister-taxa pairs. We find endemic serpentine taxa occur in serpentine habitats averaging twice as much bare ground as tolerator serpentine taxa and 25% less soil calcium, a limiting macronutrient in serpentine soils. We do not find strong evidence that habitat divergence between sister taxa of endemic pairs is greater than between sister taxa of tolerator pairs. These results suggest serpentine endemism is associated with adaptation to chemically harsher and more bare serpentine habitats. It may be that this adaptation trades off with competitive ability, which would support the longstanding, but rarely tested, competitive trade-off hypothesis.

Spatial phylogenetics of the native California flora

BackgroundCalifornia is a world floristic biodiversity hotspot where the terms neo- and paleo-endemism were first applied. Using spatial phylogenetics, it is now possible to evaluate biodiversity from an evolutionary standpoint, including discovering significant areas of neo- and paleo-endemism, by combining spatial information from museum collections and DNA-based phylogenies. Here we used a distributional dataset of 1.39 million herbarium specimens, a phylogeny of 1083 operational taxonomic units (OTUs) and 9 genes, and a spatial randomization test to identify regions of significant phylogenetic diversity, relative phylogenetic diversity, and phylogenetic endemism (PE), as well as to conduct a categorical analysis of neo- and paleo-endemism (CANAPE).ResultsWe found (1) extensive phylogenetic clustering in the South Coast Ranges, southern Great Valley, and deserts of California; (2) significant concentrations of short branches in the Mojave and Great Basin Deserts and the South Coast Ranges and long branches in the northern Great Valley, Sierra Nevada foothills, and the northwestern and southwestern parts of the state; (3) significant concentrations of paleo-endemism in Northwestern California, the northern Great Valley, and western Sonoran Desert, and neo-endemism in the White-Inyo Range, northern Mojave Desert, and southern Channel Islands. Multiple analyses were run to observe the effects on significance patterns of using different phylogenetic tree topologies (uncalibrated trees versus time-calibrated ultrametric trees) and using different representations of OTU ranges (herbarium specimen locations versus species distribution models).ConclusionsThese analyses showed that examining the geographic distributions of branch lengths in a statistical framework adds a new dimension to California floristics that, in comparison with climatic data, helps to illuminate causes of endemism. In particular, the concentration of significant PE in more arid regions of California extends previous ideas about aridity as an evolutionary stimulus. The patterns seen are largely robust to phylogenetic uncertainty and time calibration but are sensitive to the use of occurrence data versus modeled ranges, indicating that special attention toward improving geographic distributional data should be top priority in the future for advancing understanding of spatial patterns of biodiversity.

Rare Lichens Collected in California by Judith (Judy) and Ron Roberston

Judy and Ron Robertson were outstanding amateur lichenologists in California. Their huge lichen collection (over 8,500 collections) was donated to the University of California Herbarium after their deaths. This article describes 36 unusual lichens that they collected in California, together with their provenance, many of them extremely rare or new to the California flora.

Persistence of historical population structure in an endangered species despite near-complete biome conversion in California's San Joaquin Desert.

Genomic responses to habitat conversion can be rapid, providing wildlife managers with time-limited opportunities to enact recovery efforts that use population connectivity information that reflects predisturbance landscapes. Despite near-complete biome conversion, such opportunities may still exist for the endemic fauna and flora of California's San Joaquin Desert, but comprehensive genetic data sets are lacking for nearly all species in the region. To fill this knowledge gap, we studied the rangewide population structure of the endangered blunt-nosed leopard lizard Gambelia sila, a San Joaquin Desert endemic, using restriction site-associated DNA (RAD), microsatellite and mtDNA data to test whether admixture patterns and estimates of effective migration surfaces (EEMS) can identify land areas with high population connectivity prior to the conversion of native xeric habitats. Clustering and phylogenetic analyses indicate a recent shared history between numerous isolated populations and EEMS reveals latent signals of corridors and barriers to gene flow over areas now replaced by agriculture and urbanization. Conflicting histories between the mtDNA and nuclear genomes are consistent with hybridization with the sister species G.wislizenii, raising important questions about where legal protection should end at the southern range limit of G.sila. Comparative analysis of different data sets also adds to a growing list of advantages in using RAD loci for genetic studies of rare species. We demonstrate how the results of this work can serve as an evolutionary guidance tool for managing endemic, arid-adapted taxa in one of the world's most compromised landscapes.

Flowering time evolution is independent of serpentine tolerance in the California flora

AbstractComparative phylogenetic tests have been only recently applied to the many hypotheses about the role ultramafic (serpentine) soils play in the evolution and ecology of regional floras. An association between serpentine tolerance and early flowering has been observed at microevolutionary scales but not yet tested broadly across angiosperms. I used both hypothesis testing (phylogenetically independent contrasts) and model‐selection approaches to compare published data of serpentine tolerance with flowering time using phylogenetic trees representing 24 clades of plants representing 27 genera and 17 families. A total of 126 independent contrasts revealed no significant difference in flowering times across all clades or within any one clade except for the Thelypodieae, in which flowering time of serpentine‐tolerant lineages was later. Similarly, an Ornstein‐Uhlenbeck model with one optimal flowering time was preferred over a model with separate optima depending on serpentine tolerance in nearly all genera. A phylogenetically un‐corrected ANOVA found that serpentine‐tolerant species have an earlier distribution of flowering times compared to both endemic and non‐tolerant species, and median flowering times of non‐tolerant species show a bimodal distribution. Therefore, I conclude that the long‐term evolutionary responses of flowering time in a lineage that becomes tolerant of serpentine are variable across genera, with no significant overall bias toward earlier or later flowering. However, given that close relatives of serpentine‐tolerant lineages tend to also flower relatively early, early flowering time may serve as an exaptation for serpentine tolerance. In combination with previously published ecotype studies, these results illustrate the eco‐evolutionary scale dependence of flowering time.

Not All Plant Taxa Display Typical Latitude-Propagule Size Gradients: A Case Study In Arctostaphylos L. (Ericaceae)

Proposed causes of the latitudinal-propagule size gradient invoke differences among biome structures or seed dispersal syndromes. Latitudinal seed-size gradients so far have been predominantly investigated using entire floras, prompting the question of whether such trends exist at smaller scales. Here we consider effects of latitude and elevation on fruit size between and within species in Arctostaphylos L. (Ericaceae), a zoochorous, primarily Californian chaparral shrub genus. We measured fruit size, strongly correlated with seed size in Arctostaphylos, in three species of this genus from multiple localities in the Sierra Nevada foothills, and conducted a character analysis of fruit size across the genus using the standard California flora plant manual (Baldwin et al. 2012). Across the genus we found a weak negative correlation between fruit size and latitude (0.0026 mm diameter/km) and a weak positive correlation between fruit size and elevation (1.3 mm diameter/km). AIC indicates that these trends are not explained by autocorrelation between fruit size and other variables such as maximum plant size. By contrast, intraspecific field data revealed a positive relationship between fruit size and both elevation and latitude. Propagule size gradients within Arctostaphylos oppose those reported for angiosperms globally. This contrast may result from uniformity of fruit structure and animal dispersal, disturbance ecology of chaparral, or local precipitation gradients characteristic of Mediterranean-type climates. Studies of propagule size gradients within taxa can uncover ecological mechanisms behind this trend that remain obscure at global scales.

Species richness and endemism in the native flora of California.

California's vascular flora is the most diverse and threatened in temperate North America. Previous studies of spatial patterns of Californian plant diversity have been limited by traditional metrics, non-uniform geographic units, and distributional data derived from floristic descriptions for only a subset of species. We revisited patterns of sampling intensity, species richness, and relative endemism in California based on equal-area spatial units, the full vascular flora, and specimen-based distributional data. We estimated richness, weighted endemism (inverse range-weighting of species), and corrected weighted endemism (weighted endemism corrected for richness), and performed a randomization test for significantly high endemism. Possible biases in herbarium data do not obscure patterns of high richness and endemism at the spatial resolution studied. High species richness was sometimes associated with significantly high endemism (e.g., Klamath Ranges) but often not. In Stebbins and Major's (1965) main endemism hotspot, Southwestern California, species richness is high across much of the Peninsular and Transverse ranges but significantly high endemism is mostly localized to the Santa Rosa and San Bernardino mountains. In contrast, species richness is low in the Channel Islands, where endemism is significantly high, as also found for much of the Death Valley region. Measures of taxonomic richness, even with greater weighting of range-restricted taxa, are insufficient for identifying areas of significantly high endemism that warrant conservation attention. Differences between our findings and those in previous studies appear to mostly reflect the source and scale of distributional data, and recent analytical refinements.

Long-term demographic decline and late glacial divergence in a Californian paleoendemic: Sequoiadendron giganteum (giant sequoia).

Mediterranean ecosystems comprise a high proportion of endemic taxa whose response to climate change will depend on their evolutionary origins. In the California flora, relatively little attention has been given to the evolutionary history of paleoendemics from a molecular perspective, yet they number among some of the world's most iconic plant species. Here, we address questions of demographic change in Sequoiadendron giganteum (giant sequoia) that is restricted to a narrow belt of groves in the Sierra Nevada Mountains. We ask whether the current distribution is a result of northward colonization since the last glacial maximum (LGM), restriction of a broader range in the recent past (LGM) or independent colonizations in the deeper past. Genetic diversity at eleven microsatellite loci decreased with increasing latitude, but partial regressions suggested this was a function of smaller population sizes in the north. Disjunct populations north of the Kings River were divergent from those south of the Kings River that formed a single cluster in Bayesian assignment tests. Demographic inferences supported a demographic contraction just prior to the LGM as the most likely scenario for the current disjunct range of the species. This contraction appeared to be superimposed upon a long‐term decline in giant sequoia over the last 2 million years, associated with increasing aridity due to the Mediterranean climate. Overall, low genetic diversity, together with competition in an environment to which giant sequoia is likely already poorly adapted, will pose major constraints on its success in the face of increasing aridity.

Altitudinal shifts of the native and introduced flora of California in the context of 20th‐century warming

AbstractAimThe differential responses of plant species to climate change are of great interest and grave concern for scientists and conservationists. One underexploited resource for better understanding these changes are the records held by herbaria. Using these records to assess the responses of different groups of species across the entire flora of California, we sought to quantify the magnitude of species elevational shifts, to measure differences in shifts among functional groups and between native and introduced species, and to evaluate whether these shifts were related to the conservation of thermal niches.LocationCalifornia.MethodsTo characterize these shifts in California, we used 681,609 georeferenced herbarium records to estimate mean shifts in elevational and climatic space of 4426 plant taxa. We developed and employed a statistical method to robustly analyse the data represented in these records.ResultsWe found that 15% of all taxa in California have ranges that have shifted upward over the past century. There are significant differences between range shifts of taxa with different naturalization statuses: 12% of endemic taxa show significant upward range shifts, while a greater proportion (27%) of introduced taxa have shifted upward. We found significant differences between the proportion of significant range shifts across taxa with different seed sizes, but did not find evidence for differences in shift based on life‐form (annual versus perennial, herbaceous versus woody).Main conclusionsOur analyses suggest that introduced species have disproportionately expanded their ranges upward in elevation over the past century when compared with native species. While these shifts in introduced species may not be exclusively driven by climate, they highlight the importance of considering the interacting factors of climate‐driven range shifts and invasion to understand how floras are responding in the face of anthropogenic change.

Species‐specific phenological responses to winter temperature and precipitation in a water‐limited ecosystem

Phenology is the study of seasonal biological events such as flowering, leaf‐out, insect emergence, and animal migration. Long‐term observational studies at numerous temperate zone sites have found that the timing of phenological events responds to temporal variation in climate. To assess the phenological effects of climatic variation on California's flora, The California Phenology Project (CPP) was established in 2010 to develop and to test monitoring protocols and to create tools to support long‐term phenological monitoring and education in several California national parks. The CPP uses standardized protocols developed in collaboration with the USA National Phenology Network (USA‐NPN) to track the phenological status of 30 plant species across key environmental gradients (e.g., latitude, elevation, and precipitation). To date, over 860K phenological records collected by trained citizen scientists, natural resource managers, and park interns participating in the CPP have been contributed to the National Phenology Database. Observations recorded up to twice per week during the first 40 months of monitoring by the CPP were of sufficiently high resolution to detect associations between local climatic conditions and the onset of targeted phenophases. Here, we present analyses of four of the most intensively‐monitored species: Baccharis pilularis (Asteraceae), Quercus lobata (Fagaceae), Sambucus nigra (Caprifoliaceae), and Eriogonum fasciculatum (Polygonaceae). We examined the effects of monthly climate parameters during a four month window (December to March), including mean minimum temperatures (Tmin), total monthly precipitation, and their interactions, on the onset dates of four phenophases per species. Stepwise regressions explained a high proportion (30–99%) of the variation in the onset date of each phenophase. Species and phenophases differed, however, with respect to the strength and the direction of the relationship between each month's conditions (Tmin and/or precipitation) and the timing of vegetative and reproductive phenophases. Given the high climatic variation represented among the monitored sites and among years (2011–2013), it was possible to detect significant associations between local, recent winter conditions and the onset dates of subsequent phenophases, although interactions between monthly conditions were also common. These patterns permit preliminary predictions regarding how these species will respond to future winter warming and intensifying drought.

Three New Subspecies ofMonardella(Lamiaceae) from Southern California, U.S.A.

Continuing work on the flora of California after the publication of The Jepson Manual: Vascular Plants of California has led to the discovery of three new Monardella Benth. (Lamiaceae) subspecies: M. australis Abrams subsp. gabrielensis Elvin & A. C. Sanders, M. australis subsp. occidentalis Elvin, R. A. Burgess & A. C. Sanders, and M. sinuata Elvin & A. C. Sanders subsp. gerryi Elvin, A. C. Sanders & R. A. Burgess. Monardella australis subsp. gabrielensis occurs in the central and western San Gabriel Mountains of the Transverse Ranges, and M. australis subsp. occidentalis occurs on Pine Mountain Ridge in the Western Transverse Ranges and the San Rafael Mountains of the adjacent southern portion of the South Coast Ranges. The two new subspecies of M. australis are most similar to the autonymic subspecies, but both differ in their bract and leaf morphology, pubescence on the stems and calyces, stature, and distribution. Monardella sinuata subsp. gerryi occurs in the Las Posas and Camarillo Hills in the coastal plain of Ventura County in the South Coast Region. The new subspecies is most similar to M. sinuata subsp. sinuata but differs in its stem, leaf, bract, and glomerule size and in its pubescence, nutlets, and ecological setting. Monardella neglecta Greene is transferred to a new rank as a subspecies of M. purpurea Howell, as M. purpurea subsp. neglecta (Greene) Elvin & A. C. Sanders. It is a diminutive, glabrous, serpentine endemic on the Marin and Tiburon peninsulas in northern California. A taxonomic assessment of names within the M. villosa Benth. complex results in the synonymy of M. franciscana Elmer to M. villosa subsp. villosa. Monardella villosa subsp. subserrata (Greene) Epling is recognized as the upland and interior taxon in this species. A lectotype is designated for M. purpurea Howell and recognized for both M. franciscana Elmer and M. neglecta Greene.