The Rare Plant Phenology Forum is a place for field botanists to share observation data relating to flowering and fruiting times, as well as the general location of California’s rare plant taxa. Sharing these types of observations assists field botanists, researchers, consultants, and others on when to conduct field studies and surveys on the subject taxon. This forum is only as rich as the number of contributors that provide this type of data. The data that contributors provide is not expected to be voluminous, but is expected to be as scientifically accurate and reliable as possible. Short, succinct entries will keep this reference usable and quickly searchable for individuals seeking phenology information on a specific rare plant taxon.

Phenology forum info and how-tos

What to include when logging observation data

  1. Subject Title: The scientific name of the plant species, which should be the only text entered into the subject heading. Use the most up-to-date nomenclature as found in the CNPS Inventory. Please do not use common names and include subspecies (ssp.) or varieties (var.) when applicable (e.g. “Arctostaphylos tomentosa ssp. daciticola”). This will allow for taxon entries to be easily searchable in the forum. Before entering data for a specific taxon, the forum should be searched for existing threads of the subject species to avoid multiple threads for a single species. Each subsequent post for the same species should be posted as a reply in the appropriate species entry post.
  2. Date: The date of the observation. The date should be uniform among entries and given as “DD-Month-YYYY”
  3. Name of Observer: The first and last name of the person reporting the observation.
  4. Total No. Individuals: An estimate of the size of the population given as the total number of individuals.
  5. Phenology: An estimation of the population’s flowering, fruiting, and/or vegetative condition as a percentage; which gives a qualitative assessment of the taxon’s phenology; whether it is beginning, peaking, or ending.
  6. Location: The general location of the observation including: regional location, county, Jepson Bioregion, and elevation in feet (if possible). (Please do not use specific coordinates in order to protect against rare plant poachers and other potential threats).
  7. Notes/Observations: Any other notes and/or observations that seem relevant should also be included in the entry such as, if the population is peripheral, disjunct, a range extension (elevational or distributional), a new county record, notable or unusual seasonal weather patterns, etc.
  8. Photographs: A photo of the plant population and at least one photo of an individual plant, preferably of diagnostic features, if possible.

Sample entry

  • Subject Title: Blepharizonia plumosa
  • Date: 14-Sep-2011
  • Name of Observer: Heath Bartosh
  • Total No. Individuals: 550
  • Phenology: 50% Flowering, 50% Fruiting, 0% Vegetative
  • Location: Black Diamond Mines Regional Preserve, Contra Costa County, Border of SnJV and SnFrB; Elevation 1,500 feet.
  • Notes: This population is near the northern and western extent of the species range.
  • Photos: See attached photos of plant population and diagnostic characteristics.

Who can be a member of the Phenology forum?

Existing Rare Plant Status Review Forum members automatically have access to the Rare Plant Phenology Forum.  If you are currently not a Rare Plant Status Review Forum member, but would like to contribute to the Rare Plant Phenology Forum, please fill out and submit a Rare Plant Status Reviewer Form to Aaron E. Sims (

Instructions on registering for the forum

  1. Go to
  2. Click on the “Register” link on the top, left side of the screen.
  3. Fill in the fields on the registration form, choose your preferences and submit. Please choose a username that contains your name (e.g. joe smith, joesmith95814, etc.)
  4. After registering, email your Username and a filled out copy of the reviewer form to
  5. Once you receive an email confirmation from Aaron, log in at the top of
  6. Click on Rare Plant Phenology and select a taxon to review. Use the “Post Reply” button to share your comments/data.

Note: This discussion forum is only visible when you are logged in.

This project has been developed by the CNPS Rare Plant Program and the CNPS Rare Plant Program Committee.  Please contact Aaron E. Sims ( if you have any questions regarding the CNPS Rare Plant Program or the Rare Plant Phenology Forum.

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

Note: You will only see the forum if you are logged in.

Phenology Forum