California Floristics 1

Saturday, October 22 at 10:00-11:40 am, Fir Room

*note alternate instance of this session – Saturday at 1pm

Session Description: The field of floristics covers the range of studies focused on documenting and understanding the components of the flora of a local area, a county, regions, to the entire state, and beyond. Floristics covers the basic components that support a wide range of disciplines, from basic science to land use planning. Without understanding the flora, we are just guessing as to what the flora of a given area is, including the common and rare species. This session includes results of local floristic studies, taxonomic changes or considerations of specific taxonomic groups, and different methods and tools to conduct floristic research.

Session Chairs: David Magney (CNPS, Floristics Specialist, Sacramento, CA, USA) and Nina House (California Botanic Garden, Claremont, CA, USA)

37.1    New plant species from Mono and Inyo counties

Ann Howald (CNPS Bristlecone Chapter, Sonoma, CA, USA), Steve Matson (CNPS Bristlecone Chapter, Big Pine, CA, USA)

Mono and Inyo counties include much of the east slope of the Sierra Nevada, the White and Inyo Mountains, other major mountain ranges, and adjacent lands of the Great Basin and Mojave Deserts. Nevada lies on the far side of the eastern boundaries of these counties. The diverse and rugged terrain of Mono and Inyo counties, with extensive open lands and limited road networks, means that new species are still being found here. In recent years, several new studies of the floras of Mono and Inyo counties have been completed, with others ongoing. These studies, and other fieldwork, have found a number of plant species not previously known from these counties. Recent finds include plants newly detected in California but present in other states, such as: Castilleja angustifolia var. flavescens (Northwestern Paintbrush), Oxytropis oreophila var. juniperina (Mountain Oxytrope), and Eremothera nevadensis (Nevada Suncup). Also, several plants new to science have been described recently from Mono and Inyo counties, including: Nemacladus morefieldii (Morefield’s Threadstem), Nemacladus matsonii (Matson’s Threadstem), N. inyoensis (Inyo Threadstem), Erythranthe angulosa (Sweet-stem Monkeyflower), E. bergeri (Berger’s Monkeyflower), and E. howaldiae (Moss-bed Monkeyflower). Presently, none of the taxa mentioned above are included in The Jepson Manual. In addition, numerous species disjunct from distant parts of California recently have been detected in Mono County for the first time. In this presentation, we will discuss and illustrate a selection of new plant species from Mono and Inyo counties.

37.2    Vascular plant flora of Ladd Canyon, Santa Ana Mountains, California

Daniel Donovan (California State University, Long Beach, Long Beach, CA, USA), Amanda E. Fisher (California State University, Long Beach, Long Beach, CA, USA)

Southern California’s Santa Ana Mountains are a coastal range between Orange and Riverside counties, within the California Floristic Province global diversity hotspot. Ladd Canyon in the northern Santa Anas is an intriguing target for a floristic survey because it has relatively few access routes and has not been well explored. The steep terrain covers 18.2 km² in the Cleveland National Forest. Significant Pinus attenuata stands on the high ridges are associated with the only serpentine soil in the mountains. Local topography is thought to funnel wet marine air through the canyon, and the canyon has burned less frequently than the rest of the mountains, with no recorded burns in much of its area. A complete checklist of taxa could shed light on the effects of Ladd’s low human traffic, wetter microclimate, and low fire frequency. As of August 2022, I have made 79 trips to Ladd Canyon, including three overnights, and made 692 collections. The vouchered checklist has 324 taxa (9 based only on previous records). Sensitive taxa in Ladd Canyon include Lepechinia cardiophylla (CRPR 1B.2), Calochortus weedii var. intermedius (1B.2), Monardella hypoleuca ssp. intermedia (1B.3), Lilium humboldtii ssp. ocellatum (4.2), Romneya coulteri (4.2.), Rhinotropis [Polygala] cornuta var. fishiae (4.3), Allium haematochiton (NatureServe N3N4), and Palmerella debilis subsp. serrata (NatureServe G3T3). There are 113 annual taxa (34.9%), compared with 39% annual taxa across the Santa Ana Mountains and 44% in San Mateo Canyon in the southern part of the range. There are 269 native taxa and 55 non-native taxa (including 19 invasive and 3 cultivated), yielding 17% non-native and 7.1% invasive taxa. The more frequently visited San Mateo Canyon has 20.1% non-native taxa, and the entire range 22.5%.

37.3    The rich flora of Ventura County, California

David L. Magney (California Native Plant Society, Sacramento, CA, USA)

The vascular plant flora of Ventura County, California is rich and diverse, consisting of approximately 1,951 native specific and infraspecific taxa and 2,657 native and naturalized taxa. Ventura County is 4,806.1 square kilometers (1,855.6 square miles) and ranges in elevation from sea level to 2,692 meters (8,831 feet). The flora is represented by 766 genera in 158 families. Approximately 73% of the plants are native taxa. While Ventura County only represents 1% of the land area of California, it contains 37% of the California flora (native and naturalized). It ranks second in species richness only to San Bernardino County, which is more than three times the size of Ventura County. Ventura County has more taxa than 13 states and 2 districts/territories of the United States of America.

37.4    A Vascular Flora of the Manter and Salmon Creek Watersheds in the southern Sierra Nevada, Tulare County, California

Nina House (California Botanic Garden, Claremont Graduate University, Claremont, CA, USA)

The Manter and Salmon Creek watersheds occur in the southern Sierra Nevada, Tulare County, California, and encompass a 51 sq. mi. section of the Kern Plateau. This region is known to host numerous endemic plant species (e.g. Frasera tubulosa and Horkeliella purpurascens) and species of conservation concern (e.g. Eriogonum breedlovei var. shevockii and Carlquistia muirii). The Domeland Wilderness, which makes up 25 sq. mi. of the study site, has few herbarium specimen records documenting plant diversity. Conducting a systematic floristic inventory of this under-documented region provides an opportunity to record rare plant locations, new county records, species at the edge of their range, and disjunct plant populations. Documenting this diversity is vital, as there are several ongoing impacts from land use and climate change. Cattle grazing, off highway vehicular use, logging, severe drought, and the impacts of an altered fire regime were all documented during the study. These disturbances will have lasting impacts on the flora. Throughout the project, I completed a total of 24 field trips, totaling 90 field days, and resulting in the collection of 1,412 herbarium specimen records. The primary goal of this project was to produce an annotated checklist of the regional flora. With field work, plant identification, and analyses for this project complete, I will be presenting an overview of the study area and will place this into a conservation context.

37.5    California cholla changes: Recent research and taxonomic changes in the Cylindropuntia of southern California and Baja California

Michelle Cloud-Hughes (Desert Solitaire Botany and Ecological Restoration, San Diego, CA, USA), Marc Baker (Arizona State University, Tempe, AZ, USA), Lucas Majure (Florida Natural History Museum, Gainesville, FL, USA), Jon Rebman (San Diego Natural History Museum, San Diego, CA, USA)

Recent genetic studies within the genus Cylindropuntia have revealed evolutionary relationships at the clade, species, and, in some cases, intraspecific levels. Morphological analyses of the genus have generally supported these genetic results. Results of these studies within the Californica clade of Cylindropuntia, comprising species occurring in California and Baja, have raised several questions regarding relationships between taxa, particularly among the C. alcahes and C. californica subspecies. This talk presents a summary of our current knowledge of the Californica clade of Cylindropuntia, including recent name changes, and discusses the major questions still to be addressed.