CNPS MISSION/STRATEGIC/DIRECTION: Vegetation mapping and classification, Rare Plants, Know.

ORANGE COUNTY CHAPTER FOCUS: Know where plants were, are, could be – and why.

Plant Science by the Numbers – Orange County (OC) / California (CA)


OC:    2,460 sq km
CA: 423,970 sq km

Wikipedia accessed 2023 July 20

Floristic Provinces

OC: 1 – California (Mediterranean climate)

CA: 3 – California, Great Basin, Sonoran Desert

Native Plants

OC: 1,638 taxa
CA: 9,061 taxa

Calflora web application accessed 2023 July 20.

Non-Native Plants

OC:   843 plants
CA: 2,163 plants

Calflora web application accessed 2023 July 20.

Rare or Imperiled (G1, G2 rank)

OC:   21 native species
CA:  758 native species

CNPS Rare Plant Inventory web application-Global Rank filters-accessed 2023 July 20


S. CA Coast Ecological Section: 146 alliances
CA: 447 alliances

CNPS Manual of California Vegetation Online accessed 2023 July 20.

and Moths

OC:    ~300 species
CA: ~ 1,350 species

CNPS Calscape web application-Butterflies to host plant section-accessed 2023 July 20.

Non-Native Plants

OC: 221 species
CA: 224 species

Cal-IPC web application-filtered for high, moderate, and limited-accessed 2023 July 20.

Useful Resources

CNPS HIGH VALUE GO-TO RESOURCES: CNPS is a significant contributor to knowledge about California's rare plants, vegetation patterns, and associated field work. Here are the the direct links.

RARE PLANT PROGRAM:  Since its inception in 1968, the CNPS Rare Plant Program has been a trusted resource for scientific accuracy and integrity. CNPS rare plant data are widely accepted as the standard for information on the rarity and endangerment status of the California flora.

RARE PLANT INVENTORY:  First published in 1974, the Inventory is a widely-accepted authoritative resource on California’s rare and endangered plants. Now in its 8th edition and easily searchable online, it continues to play an important role in scientific research, conservation planning, and the effective enforcement of environmental laws.

VEGETATION PROGRAM:  The CNPS Vegetation Program has established a vegetation classification system that has become the standard for interpreting statewide vegetation patterns and for initiating local and regional ecological assessments.

MANUAL OF CALIFORNIA VEGETATION:  The MCV is California’s definitive system for describing vegetation statewide. It uses a principal unit called an “Alliance” (or series), which is a floristically defined vegetation type identified by its dominant and/or characteristic species. Search by species, primary life form, map, rarity, and more.

FIELD PROTOCOLS & GUIDELINES: CNPS staff, collaborators, and volunteers have all played an important role in helping us refine and present best-practice approaches to field surveys, sampling, mapping, and mitigation.

CALSCAPE: This website is useful to both the science oriented and gardeners. Information includes botanic descriptions and California range maps. Other data provided may include wildlife supported, growing information, climate preferences, and nurseries that have sold the plant.  Many search criteria are available.

LOCAL FLORAS and PLANT LISTS COMPILED BY THE CNPS OC CHAPTER: A list of plants in a specific region and/or time period is called a Flora. Our documents from 1951 to the present can have valuable science, research, and conservation value. We are making sure they stay easily findable in the public domain. Included are recent in-depth survey projects involved with our chapter... The Holy Fire Recovery, Caspers Wilderness Park survey project, and the Whiting Ranch Wilderness Park survey project.

Casper’s Wilderness Park Vascular Plant List 2022; M Simpson, R Crowe, R Vanderhoff, CCH2 website
Flora of Caspers Wilderness Park 2002; Bob Muns, J Strong, T Chester, website
Coal Canyon Plant List – Chino Hills State Park, 2024; R. Vanderhoff
Santa Anta Mts., Holy Fire Surveys – 2019, Vanderhoff, Roberts, Allen and Plant Data tables
Vascular Flora of the S
Biota of the Santa Ana Mts, 1951, W. Pequegnat – too big for WP
Santa Ana Mts., Vascular Plant Additions – 2001, Boyd; pdf
Plants of Lucas Canyon, San Mateo Wilderness, 2014; Ron Vanderhoff; pdf
Bryophytes of the San Juan Loop Trail, Paul Wilson; pdf
Flora of the San Mateo Canyon Wilderness 1995; Boyd, Ross, Mistretta, Bramlet; PDF- too big for WP
Flora of Audubon’s Starr Ranch; Ernest Clarke, Audubon; website
Sinks – Hangman’s Tree Rd – Markel Spur, Plant list – 2003; pdf
Elsinore Peak Plant List,  Steve Boyd, 2003; pdf
Flora of the Santa Rosa Ecological Reserve, T. Chester; website


Flora of Crystal Cove State Park; T. Chester; website
Flora of Laurel Canyon, Laguna Coast Wilderness Park; B. Muns, T. Chester; website
Laguna Beach Biological Resources; Karlin Marsh – too big for WP
Laguna Canyon Biological Resources; Karlin Marsh – too big for WP
South Laguna Biological Resources; Karlin Marsh – too big for WP


Common Plants of Upper Newport Bay; Don Millar; website
Flora of the Newport Beach Civic Center Park, 2014; Ron Vanderhoff; pdf
Plants of the UCI Ecological Preserve, 2003; P. Bowler, D. Bramlet; pdf
Vascular Plant Checklist of the San Joaquin Marsh, 2004; P. Bowler & M. Elvin; pdf
Vascular Plant Checklist of the San Joaquin Marsh, 2004; P. Bowler & M. Elvin (Updated to JEP II)


Bryophytes and Lichens OC Checklist, Chris Wagner, UCR, 01-2023
Bryophyte Field Collection Envelope, Chris Wagner, UCR; docx


CALFLORA: A repository for information on California wild plants from diverse sources, including public agencies, academic institutions, private organizations, and individuals.

CALPHOTOS: From UC Berkeley, a huge collection of photos of plants, animals, fossils, people, and landscapes from around the world.


FLORA OF NORTH AMERICA: Presents in one published reference source, information on the names, taxonomic relationships, continent-wide distributions, and morphological characteristics of all plants native and naturalized found in North America north of Mexico.

iNATURALIST: iNaturalist is a citizen science project and online social network of naturalists, citizen scientists, and biologists built on the concept of mapping and sharing observations of biodiversity across the globe. iNaturalist is a joint initiative of the California Academy of Sciences and the National Geographic Society.

JEPSON eFLORA: The foremost authority on the native and naturalized vascular plants of California. For plants occurring in wildlands or otherwise outside of cultivation, the Jepson eFlora contains taxonomic treatments, distribution maps, illustrations, photographs, and identification keys.

NATURAL HISTORY OF ORANGE COUNTY; Peter Bryant:  A local gem with photos and descriptions of Orange County biology. Compiled by Peter J. Bryant, School of Biological Sciences, University of California, Irvine.

VEGETATION CLASSIFICATIONS OF ORANGE COUNTY; Nature Reserve of OC:  Extensive survey information of vegetation alliances found in Orange County. Includes amount of specific species cover found under each alliance.

CALIFORNIA NATURAL DIVERSITY DATABASE; California Dept of Fish and Wildlife:  BIOS is a system designed to enable the management, visualization, and analysis of biogeographic data collected by the California Department of Fish and Wildlife and its Partner Organizations.

WILDFLOWERS OF ORANGE COUNTY AND THE SANTA ANA MOUNTAINS, R. Allen, F. Roberts:  We can not say it enough – this book is the essential guidebook for Orange County flowering plants.

JEPSON MOSS eFLORA:  It is a collaborative effort of a broad group of professional and amateur bryologists, coordinated by UC Berkeley and Cal State Northridge.

FUNGI RESOURCES 2022, Joanne Schwartz:  Field Guides, Background Books, Cookbooks, Organizations, Websites.


CA INVASIVE PLANT COUNCIL:  Works to stop the spread of invasive plants across California. The respected Cal-IPC Inventory identifies plants that threaten California’s natural areas.

WILDFLOWER HOTLINE (Theodore Payne Foundation):  Offers free weekly on-line and recorded updates – posted each Friday from March through May – on the best locations for viewing spring wild flowers in Southern and Central California.

DESERT USA FLORA:  Where are desert wildflowers blooming in California and across the southwest? Desert USA knows and updates regularly.