California Botanical Society

Paul Silva in 1954 in Collioure, France

Paul Silva Student Research Grants

The Paul Silva Student Research Grant is named after Paul Silva (1922-2014), a phycologist and Curator of Algae at the University Herbarium, UC Berkeley, whose bequest to the Society has made this award possible. Awards are made to qualified undergraduate and graduate student members of the Society working on projects that will help achieve the Society's goal of advancing Western American botany. Students from any accredited university doing botanical research within western North America and who are members of the Society are eligible for this award.

The next deadline for receipt of applications for a Paul Silva Student Research Grant is May 31, 2018. Proposals will be reviewed by a panel of experts, and winners will be announced within two months of the application deadline.

For application details and application form are here:

Application Details

Application Form

2017 Recipients

Jennifer Harrower, University of California, Santa Cruz

Investigating the Impacts of Climate Change on Joshua Trees and their Symbionts: Joshua trees are threatened by rapid climate change and may be locally extinct from their namesake national park within a century. These iconic trees form symbiotic relationships with moth pollinators and root fungi that is essential to plant growth and reproduction. Joshua trees are limited to a narrow range of climate conditions and must spread to new habitats following the changing climate, but it is unknown if their obligate symbionts will move in synchrony or how changing environmental conditions will impact symbiosis. This study proposes to use climate gradients in Joshua Tree National Park to study the distribution of Joshua trees, their pollinators and symbiotic root fungi, and the outcomes of those interactions on plant performance. The results of this research will contribute directly towards shaping Joshua tree conservation policy by providing detailed information on the distribution and interactions of Joshua trees and their symbionts, and inform the creation of a multimedia art exhibit that will be shown in both art and science venues.

Nila Le, University of San Francisco

Climate change and limited distribution of the California native plant and rocky outcrop endemic Arabis blepharophylla: Why do some species have broad geographic distributions while other species are confined to a narrow distribution? This is a central question in ecological research, particularly for plants, which are sessile and confined to the environment where they germinate. Arabis blepharophylla (Brassicaceae) is a California native, endemic, and rare perennial herb that ranges central coastal California, concentrated in the San Francisco Bay Area and adjacent Coast Ranges. What is driving A. blepharophylla’s limited distribution along the central California coast? Arabis blepharophylla occurs exclusively on isolated coastal bluffs, rocky outcrops, and serpentine ridges. This unique distribution results in the potential for limited dispersal of seeds among populations, which can restrict range expansion. Likewise, a patchy distribution can result in reduced pollen flow and the formation of genetically distinct, isolated populations. Many of the locations that A. blepharophylla has historically been documented have not been officially updated for decades, and in some cases since the late 1800s! We suspected that A. blepharophylla’s range has been reduced from its already restricted distribution and low abundance due to anthropogenic disturbance and climate change. If A. blepharophylla’s range has been significantly reduced over the past century, this species could be a fitting candidate for listing under the Native Plant Protection Act or the California Endangered Species Act. To understand what factors regulate this species’ distribution, I will use a combination of field, greenhouse, analytical, and molecular lab techniques. For my Master’s research, I am investigating two key questions: 1) the roles of limited dispersal and microhabitat specificity in explaining this species’ narrow distribution, and 2) the potential for genetic divergence among populations. This summer, I will perform molecular laboratory work to infer A. blepharophylla’s population genetic structure using cutting edge next-generation DNA sequencing techniques. Specifically, I hypothesize that A. blepharophylla’s fragmented distribution has resulted in genetically isolated populations that may represent evolutionarily significant units (ESUs; genetically unique populations). The discovery of genetically unique lineages may be critical in guiding conservation decisions for this species.

Annie Ayers, Kate Miller, Drew Burke, and Maxwell McCollum, California Polytechnic University, San Luis Obispo

A floristic survey of Mt. Conness and Skelton Plateau in Yosemite National Park: Scattered along the crest of the Sierra Nevada in California are fragments of ancient landscapes surrounded by glacially carved chasms. Effectively an archipelago of high elevation islands, these unglaciated sites harbor a diverse assemblage of long-living alpine plants that are adapted to cold, short growing seasons and are reliant on water from winter snowpack and summer monsoons. How this specialized plant community responds to climate fluctuations, such as the recent 6-year drought, may indicate how it will fare with predicted climate warming for the region. The purpose of this study is twofold: 1) document plant diversity and abundance to establish a baseline for this plant assemblage, and 2) test whether shifts in population abundance and elevation have occurred since the recent drought. In 2010, more than 600 plots were established at twelve unglaciated sites in Yosemite National Park. Within each plot, we identified all species, estimated their percent cover, and recorded plot elevation, slope, aspect and moisture. We selected two sites for resampling in 2017: the south slope of Mt Conness and Skelton Ridge, north of Tuolumne Meadows. In 2010, we found that plots at these two sites contained 98 and 129 species respectively, including 11 CNPS special-status species. Within the sites, species diversity declined with increasing elevation, but was highly variable across microenvironments--wet areas harbored significantly more species, including more special status species. Ongoing comparisons between 2010 and 2017 surveys will reveal what changes, if any, have occurred during the recent drought event.

Past Recipients

2017 - Jennifer Harrower, University of California, Santa Cruz: Investigating the impacts of climate change on Joshua trees and their symbionts

2017 - Nila Le, University of San Francisco: Climate change and limited distribution of the California native plant and rocky outcrop endemic Arabis blepharophylla

2017 - Annie Ayers, Kate Miller, Drew Burke & Maxwell McCollum, California Polytechnic University, San Luis Obispo: A floristic survey of Mt. Conness and Skelton Plateau in Yosemite National Park

2016 - Kristen Peach, University of California, Santa Barbara: Predicting responses of wild plant populations to climate change: Integrating climatic and biological factors influencing the ecology of floral attraction

annettacarter1932 Annetta Carter in 1932 on the Calypso Club trip to Ft. Bragg

Photo: Debra Valov

The Annetta Carter Memorial Fund

The Annetta Carter Memorial Fund honors Annetta Carter, who devoted the last 40 years of her life to the study of the Baja California flora. Her special interests were floristics, history, biogeography, and ethnobotany of the Sierra de la Giganta.

The review committee will consider proposals from members of the California Botanical Society who are conducting or proposing to conduct botanical research on the green plants of Baja California. Studies of populations outside Baja will also be considered if they elucidate problems in Baja California.

Application details are here:

- In English

- En Español

Next deadline is December 31, 2019


2018 - Isaac H.L. Marck: Revising the Systematics of Amauri, the Baja California endemic road daisies

2018 - Benjamin T. Wilder: Botanical Diversity and Change of Volcan Tres Virgenes

2016 - Andy Siekkinen: Searching for Hechtia gayorum, the Baja Endemic Bromeliad

2014 - C. Matt Guilliams: Distribution, extent, and floristics of vernal pools in Baja California, Mexico

2014 - Daniel E. Winkler: Reconnaissance of the status of a rare, endemic plant species in Sierra de San Pedro Mártir National Park, Baja California, Mexico

2012 - Kristen Hasenstab-Lehman: The vascular flora of Greater San Quintin, Baja California, Mexico

2010 - Christopher DiVittorio: Adaptive radiation of Encelia (Asteraceae) in Baja California

2008 - Sula Vanderplank: The vascular flora of Greater San Quintin, Baja California, Mexico

2006 - Peter J. Garcia: Plant collecting on Isla Angel, Sea of Cortez

2005 - Jon P. Rebman: Checklist of the plants of Lower California, Mexico

IMG_7113 Justen Whittall, Madroño Editor, with Arjun (left) and Ayana (right)

CBS award winners.Santa Cruz Justen Whittall with (starting from left) Ashlyn, Caitlin and Emma

California Botanical Society
Student Science Fair Prizes

The Society awards prizes from time to time to middle and high school student scientists for botanical projects presented at recognized California science fairs. The program was initiated in 2018 and is aimed to encourage our next generation of botanists.


2018 Synopsys Championship (Santa Clara County, California)

  • Anaya Subramanian, Los Altos High School, Los Altos, CA: Enhancement of mitochondrial function and seed germination by pterostilbene, ellagic acid and nicotinamide riboside (1st place High School division)
  • Alexander Michael Noriega, Oak Grove High School, San Jose, CA: Antimicrobial Synergies of the Digestive Juices Formed by Nepenthaceae Plants (2nd place High School division)
  • Ayana Rose Wilmot, Oakwood School, Morgan Hill, CA: Factors Affecting the Rate of Photosynthesis of California Lichens (1st place Middle School division)
  • Arjun Rajaram, Challenger School-Almaden, San Jose, CA: The effect of different plants on firescaping (2nd place Middle School division)

2018 Santa Cruz County Science & Engineering Fair

  • Emma Schaefer-Whittall, Scotts Valley High School, Scotts Valley, CA: Alkaloid Quantification of Catharanthus roseus and Vinca major and its Effects on Cell Viability (1st place High School division)
  • Isabel O'Malley-Krohn, Pacific Collegiate School, Santa Cruz, CA: Trees for the People: Socioeconomic Distribution of Street Trees (2nd place High School division)
  • Caitlin Sullivan, Holy Cross School, Santa Cruz, CA: Effects of X-Ray Radiation on Plants (1st place Middle School division)
  • Ashlyn McDaniel, Baymonte Christian School, Scotts Valley, CA: Vinegar Stops Mold on Strawberries (2nd place Middle School division)