Frangula californica ssp. californica
NATIVE – CA ENDEMIC
- Eudicots are a major lineage of flowering plants; see family for general characteristics
- Buckthorn Family (Rhamnaceae)
- Evergreen shrub
- New branches have red stems
- Alternate (1 leaf at each junction with stem) and simple (not divided into leaflets)
- Smooth surface, elliptic, and leathery
- Shiny dark green upper surface; lighter green underneath
- Margins may be toothed
- Inflorescence (flower arrangement) of many small yellow-green flowers
- Ovary partly inferior (partly below the attachment of other flower parts)
- Fruit is a 2-seeded drupe (a fleshy fruit with usually 1 seed in a hard inner shell–a stone fruit); turns black when mature
- Grows to 15 ft.
- Lifespan may be 100-200 years
- Native and endemic (limited) to California
- Grows in coastal sage scrub, desert scrub, chaparral, and woodlands
- See Calflora for statewide observations of this plant
- Grows at elevations to 9,000 ft.
Uses (San Mateo County Parks prohibits removal of any natural material)
- Fruit is a food source for many mammals and birds
- Native people had many uses for coffeeberry, including
- Preparation of the inner bark for a laxative tea to counteract the binding caused by their staple food, acorns; other members of the Buckthorn family were used for this purpose as well (Tutka 2015)
- Leaves used to treat poison oak dermatitis, as well as rheumatism
- Extracts used to treat wounds and sores (antimicrobial properties)
- Early European settlers attempted and failed to make a coffee substitute from the bitter, inedible fruit (Ritter 2015)
- CAUTION – leaves and bark can be toxic if ingested
- Frangula (FRANG-yoo-luh) – perhaps from the Latin frangere, “to break,” referring to the brittle wood
- Coffeeberry – fruit and seeds resemble the fruit and seeds (beans) of Coffea species, in the Madder family (Rubiaceae), from which the drink coffee is made (Breen 2019); also, coffeeberry seeds may be roasted to create a bitter coffee substitute (Shaw 2019)
- Readily re-sprouts from root crown following fire or other disturbance
- Edgewood’s coffeeberry is classified as a subspecies
- Subspecies rank is used to recognize geographic distinctiveness, whereas variety rank is appropriate for variants seen throughout the geographic range of the species; in practice, these two ranks are not distinct
- Previously classified in the genus Rhamnus
- Host to the fungus-like microorganism Phytophthora ramorum, which causes Sudden Oak Death (SOD)
- At Edgewood, the 2 species known to be highly susceptible to SOD are coast live oak (Quercus agrifolia var. agrifolia) and Pacific madrone saplings (Arbutus menziesii)
- For a complete list of known hosts and host associates see USDA Risk Analysis for Phytophthora ramorum, pp.6-9
- May also be confused at Edgewood with other evergreen trees/shrubs with similar leaves
|California Coffeeberry||Toyon||Pacific Madrone||California Bay|
|Growth Habit||shrub||shrub / tree||tree||tree|
|Height||≤ 15 ft.||≤ 30 ft.||≤ 130 ft.||≤ 148 ft.|
|Margin (Edge)||smooth or finely toothed||serrated||smooth||smooth|
- Found in chaparral, coastal scrub, and open woodlands
- See iNaturalist for observations of Frangula californica
- Flowers May – July
- Mature fruit seen August – October
Breen, P. 2019. Rhamnus californicus. Landscape Plants. Department of Horticulture, College of Agricultural Sciences, Oregon State University.
Golden Gate National Park Conservancy. 2020. Rhamnus californica (California Coffeeberry).
Ritter, M. 2018. California Plants: A Guide to Our Iconic Flora. Pacific Street Publishing, San Luis Obispo, California.
Shaw, H. 2019. Exploring California Coffeeberries. Hunter Angler Gardener Cook.
Tutka, M. 2016. Plant Guide: California Coffeeberry. U.S. Department of Agriculture (USDA), Natural Resources Conservation Service (NRCS), National Plant Data Center.