CNPS Rare Plant Treasure Hunts

RPTHers keying out Streptanthus breweri plants

Community science that’s fun and beautiful!

Update: Rare Plant Treasure Hunts are on hold. We’ll promote new events if they become available.

The native plant community is filled with incredible volunteers who care about California’s precious  plant diversity. So in 2010, CNPS launched its Rare Plant Treasure Hunts (RPTH), partnering our scientists with volunteers to obtain up-to-date information on California’s rare plants.

Many rare plant populations haven’t been seen in decades, and some parts of the state have seen little to no botanical exploration to date. This program helps conserve our rare flora by providing valuable data to the CNPS Rare Plant Program and the California Department of Fish and Wildlife. Treasure Hunters can join an organized rare plant search or learn how to plan their own trips by attending one of our training events.

Upcoming Events

Join the Hunt!

Three ways you can make a real difference for rare plants in California.

Attend an RPTH

Just showing up and helping with a scheduled RPTH is easy an appreciated. Simply monitor the RPTH Calendar, CNPS social media, or announcements by your local CNPS chapter.

Coordinate an RPTH

Become a local RPTH coordinator and schedule hunts in your favorite areas, for your favorite rare plants! Your local chapter and CNPS RPTH staff will be available to help you plan and promote your effort.

Steward a Rare Plant

Some plants really need a caretaker — or steward.  CNPS is looking for people like you to “adopt” a rare plant in your area and monitor its status.  You’ll gather valuable data about changes in the plant’s population size (especially valuable for annual species and short-lived perennials), pollinators, seed production, seed dispersal, and more!

Behind the Scenes of a Rare Plant Treasure Hunt

See highlights from a beautiful rare plant hunt through Lobos Ranch!

More information

RPTH background and results

Cirsium fontinale obispoense. Credit David Magney.
Cirsium fontinale obispoense. Credit David Magney.

CNPS and the California Department of Fish and Wildlife (CDFW) track California’s rare plants in the California Natural Diversity Database (CNDDB), which has now provided us with a map of nearly 38,000 rare plant occurrences across the State. Right now, nearly half of those occurrences are historical, meaning that they have had no documentation in at least 20 years. Getting up-to-date information on our rare plants is critical to understanding which populations are still present and which species need our closest attention to ensure their long-term conservation.

The project has already seen some incredible results in the first 8 years since its inception: we’ve documented over 2,500 separate rare plant occurrences, and of those, nearly 1,000 occurrences are new to science! Focus areas for RPTH vary from year to year and are dependent on project funding.The California deserts were a major focus area of the project during its first four years, as many solar energy projects threaten this biodiversity hotspot. In other years we have focused on the Los Padres National Forest, other National Forests, and the Central Coast. In 2015 we focused on Northern California and the Bay Area. Now we’re focusing on the major burn areas in the Wine County and Ventura / Santa Barbara Counties that suffered from the Thomas Fire and other recent wildfires. We’re always working to expand the Program throughout California and encourage botanical enthusiasts from all parts of the state to get involved!

Data needs

Weed’s mariposa lily (Calochortus fimbriatus) Photo: Danny Slakey

Examples of the kind of data the Rare Plant Program needs include:

  • Specific rare plant population occurrences
  • Number of plants growing at a site
  • Site conditions where the plants are growing (or are supposed to be growing)  

CNPS is  focused primarily on the rarest or the rare species, and those rare plants that have not
been observed in the wild for over 20 years.  See below for instructions and field data forms that you can download, print, and complete in the field, or you can complete the form online from your field notes and submit it electronically, whichever is the easiest approach for you. The RPTH Manager will provide you with all the information you need, such as maps, photographs of the plant, best time to search for it, etc.

RPTH collection and reporting resources

Please use only the special Rare Plant Treasure Hunt version of the CNDDB form for this project so we can track the data collected.

Important caveats on plant collection:
CNPS promotes the ethical collection of plants with appropriate permits and landowner permission, for the purpose of documenting occurrences for herbaria. CNPS requests that no plants should ever be collected without landowner permission and/or required permits. Once permission is granted, we ask that trained individuals collect the plant(s) and deposit the specimen(s) in a major California herbarium. Please follow the CNPS Policy on Ethics and Best Practices for Collecting Native Plants.

Stories from the Field

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