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Ahart Herbarium
Ahart Herbarium presents
All Things Botanically Related (Series)

Vernal Pools
Distribution and Ecology of Vernal Pools
by Carol Witham
Thursday, March 16, 2023
7-8pm
Register for Zoom >>(opens in new window)
After registering, you will receive a confirmation email containing information about joining the meeting.
Kaleidoscopes were a favorite holiday gift for children many years ago. They displayed a quickly and constantly changing series of brilliantly colored patterns. The metaphor works for California’s vernal pool landscapes.
Carol Witham will help us to explore the short-lived, weird-looking, fascinating fauna that evolved millions of years ago, and dazzling swaths of tens of thousands of tiny flowers that change from week to week through a two- to- three month “season”.
This tour of California vernal pools will answer questions such as “what makes a vernal pool” and “why are they found almost nowhere but California” plus explore vernal pools from throughout the state.

Carol Witham is a self-taught vernal pool ecologist and has been studying that ecosystem for over three decades. She is a private consultant specializing rare plants and animals of vernal pools plus their management. Carol is author of Field Guide to the Vernal Pools of Mather Field, Sacramento County and co-editor of Jepson Prairie Preserve Handbook, 3rd Edition. She is also very active in vernal pool conservation advocacy and education.
Carol is currently the treasurer for the Sacramento Valley Chapter and a member of the state board of directors of CNPS. In the past she has served in several leadership roles within the statewide organization including president, vice-president and treasurer.
All Things Botanically Related - Past Presentations:

Showy Milkweed and Diversity
Creating High Value Habitat in the Built Environment
by Pat Reynolds
River Partners Native Seed and Plant Program Director, Heritage Growers General Manager
Thursday, February 16, 2023
7-8pm
Watch the Presentation Recording >>(opens in new window)
Landscaping with native species and incorporation of habitat enhancement features within urban areas is a significant and underutilized conservation action that can effectively increase habitat values in the built environment. If designed properly, urban gardens can provide important habitat for beneficial insects including pollinators, improve water infiltration and retention, reduce irrigation requirements, combat climate change, and create resilient landscapes for the benefit of people and the environment. Pat Reynolds’ presentation will focus on the steps that go into the design, implementation and maintenance of habitat gardens dominated by native herbaceous vegetation and include the incorporation of habitat features designed to maximize ecological values and habitat function. His talk will also include discussions of some of the findings of a U.C. Davis class study that looked at the social and ecological ramifications of a habitat enhancement project that he leads in his South Davis neighborhood with hopes of inspiring others to implement similar neighborhood projects. He will also provide an update on the status of Heritage Growers, a venture of River Partners, that produces source identified native seeds and plants for habitat restoration. As part of the Heritage Growers’ update, Pat will share some of the phenology data collected and photographs taken from Heritage Growers’ 2022 demonstration garden.

Pat Reynolds is a restoration ecologist with more than 30 years of professional experience in the design, implementation and monitoring of habitat restoration projects including the effective use of native seed. He is the General Manager of Heritage Growers, River Partner’s Native Seed and Nursery Program, the former General Manager of Hedgerow Farms, and a past Associate Restoration Ecologist with H.T. Harvey & Associates. Pat sits on the Yolo County Planning Commission and is the Restoration Ecologist on the Science and Technical Advisory Committee for the Yolo County Habitat Agency. He has been a member of the California Native Grassland Association (CNGA) Board of Directors since 2017 where he often serves as an instructor for CNGA restoration workshops and events and periodically contributes to the CNGA’s Grasslands journal. Pat has a passion for the use of native plants and incorporation of habitat features in urban settings to maximize habitat values.
California Phenology Thematic Collections Network
Ahart Herbarium is actively photographing specimens in the collection and linking the images to the collection information for each species. This information is accessible through the California Phenology Thematic Collections Network (www.CCH2.org(opens in new window)). Through a National Science Foundation grant, the Herbarium will be imaging over 30,000 specimens in the collection which will be similar to the one here. Collectively, over 23 different herbaria and collections across California will be located on CCH2. Check out the website!(opens in new window)


Ahart Herbarium passed another minor milestone by accessioning its 120,000th specimen – see the number 120,000 stamped in the middle of the Herbarium logo on the lower left side of the sheet in the left photograph. This specimen is another fine example of the collecting and specimen mounting of Lowell Ahart – his collection number 21,434 from last summer.
Located in Holt Hall room 129, the Herbarium is the most complete repository of plant specimens from northeastern California. The emphasis is on the northern California flora, and includes a great number of rare, threatened, and endangered plant species. Established with specimens donated by the late Professor Vesta Holt in the 1950's, the herbarium now contains more than 107,000 dried and mounted plant specimens. The majority of samples are flowering plants, conifers, and ferns, but bryophytes, lichens, and especially slime molds, are also well represented. The herbarium is used extensively for identification of sensitive and other plant species by various agencies and individuals. Loans of herbarium specimens are made to any higher academic institutions who request them.
Facilities available to visitors to the herbarium include the use of high-quality dissecting scopes, a compound microscope, an extensive reference library, an internet-connected computer, an internet connection for personal computers, and, with suitable training, access to the collection of specimens.
Users of the herbarium facilities and collection are encouraged to make plant collections during their field excursions and donate them to the herbarium. This is how the collection grows and increases its utility and importance to the whole botanical community.
Friends of the Ahart Herbarium Workshops!
Grass (Poaceae) Identification Workshop
Due to popular demand, we are offering a second workshop on
Saturday, March 11, 2023, 9:00am – 4:30pm
(the March 4 workshop is full!)
Grasses dominate many California landscapes, yet their identification presents a challenge to beginner and experienced botanists alike. Despite their prevalence and importance in ecology and agriculture, most general plant taxonomy courses barely touch on the subject.
This workshop is intended to familiarize participants with identification of grasses using spring and summer-flowering species from the Northern Sacramento Valley, Southern Cascade and Northern Sierra Nevada ranges of California. Valley and foothill annual grasslands, montane meadows, riparian corridors, coniferous forest and rock outcrop of this region support a diverse grass assemblage and ample identification “challenges” for experts and novice alike. (Read more>> (PDF))
The workshop will meet Saturday, March 4, 2023, from 9:00 a.m. to 4:30 p.m. in Holt Hall room 129 (the Ahart Herbarium) at CSU Chico. Registration is $110.00 personal, $135.00 business, $100.00 for members of Friends of the Ahart Herbarium, and $50.00 for students (only 2 seats available at the student price). Please register in advance by filling out and mailing the registration form (PDF) and a check for the registration amount; class size is limited to 18 participants, class cancelled without at least 5 participants. For more information about workshop content please contact John Dittes at jcdittes@sbcglobal.net. For more information about registration please contact Colleen Hatfield, Herbarium Director at (530) 898-4235 or chatfield@csuchico.edu.
Register and get more info here! >> (PDF)
About the Instructor
This workshop will be led by John Dittes, Senior Biologist with Dittes & Guardino Consulting. John has 31 years of field-work experience in California and the western United States. Since 1995 he has taught plant ID workshops for the Chico State Herbarium, including Springtime Grasses (Poaceae) of California Valleys and Foothills, Summer-Flowering Grasses (Poaceae) of Northern Sierra Nevada and Southern Cascade Ranges, The Sunflowers (Asteraceae), The Pea Family (Fabaceae), Flora of Vernal Pools and Seasonal Wetlands, and Introduction to Plant Identification and the Jepson Manual.
Save the Date!
Introduction to the Willows of California (Salicaceae)
by John Bair
Saturday, June 24, 2023
California is home to over one quarter of the estimated 120 willow species growing in North America. Cottonwoods and willows are the most common riparian hardwood species in California and yet many of us have little idea of how to tell them apart. Species identification is often neglected because willows are thought to frequently hybridize, which is further compounded by only having vegetative material during field visits when we think we need flowers to make a positive identification. The workshop will focus on the leaf, stem, and other vegetative growth characteristics that are useful in making identification while also emphasizing the regional distributions of the different species. The goal of the workshop is to provide a broad overview of willows, highlight vegetative characteristics used in the identification keys in The Jepson Manual (second edition) and familiarize participants with the six most common willows in California.
Check back soon for more info!
View the Friends of the Herbarium Calendar >>(opens in new window)
Ahart Herbarium is again open to the public!
Hours are Fridays 9:00 am to 5:00 pm, and by appointment.
Visiting the herbarium is by appointment only, by contacting the Curator at ljaneway@csuchico.edu.
Visitors accessing campus facilities must comply with CSU Chico vaccination policy.
Thank you.