Photo taken near Prunedale by Dean W. Taylor
A. pajaroensis growing over A. hookeri ssp. hookeri on a shallow-soiled ridge in maritime chaparral
This fact sheet was prepared by Grey Hayes and Dean Taylor under award NA04N0S4200074 from the National Oceanic and Atmospheric Administration (NOAA), U.S. Department of Commerce (DOC). The statements, findings, conclusions, and recommendations are those of the authors and do not necessarily reflect the views of the NOAA or the DOC.
© Copyright 2006, Elkhorn Slough Coastal Training Program
Last updated: May 2, 2006 08:17
Arnold soils (soils derived from Aromas red sands) in maritime chaparral or around the edges of or under sparse canopy of coast live oak woodland. In the Prunedale hills, after a long period without fire and consequent overtopping by oaks, it occurs for the most part on ridges where soil depth and development are comparably shallow.
Mound-forming to erect shrub to approximately 2-4 m; without basal-burl; young twigs tomentose and bristly white hairy, bark exfoliates in shreds; leaves auriculate (sessile and clasping), glabrous, green to blue glaucous; inflorescence bracts leafy, exceeding the pedicels. Only auriculate-leaved manzanita within its geographic range, but similar in habit to the Santa Cruz Mountains manzanita (A. andersonii), which occurs to the north in the Santa Cruz Mountains.
December to February (identification possible throughout the year)
Manzanita County Park; Long Valley (Elkhorn Slough Foundation conservation property)
Endemic to Santa Cruz and Monterey counties in the Monterey Bay region of central California
The single site documented for Santa Cruz County in 1935 is now a residential development, and was not relocated by Griffin (1978); much suitable habitat in the Larkin Valley region of Santa Cruz County was "conserved" in the 1930s by plantations of exotic Eucalyptus globulus and southern California natives Torrey Pine (Pinus torreyana) and lemonade berry (Rhus integrifolia), eliminating maritime chaparral ecosystems. A reported location in the Santa Cruz Mountains along Ice Cream Grade is based on a mis-identification of A. andersonii.
This species requires fire to regenerate from viable seed buried in the soil. The exact triggers for germination are unknown, but may (as with other manzanitas) include a combination of both heat and chemicals from charred wood or smoke. The fire frequency necessary for stable populations is also unknown but is probably on the order of 80–100 years. Fragmentation of the habitat by housing may make utilization of controlled fire impossible.
Stands in the Prunedale region have declined owing to residential development and fire suppression (Davis 1972, Griffin 1978). One stand near Prunedale visited by Roof (1980) in 1964 and 1966 is confirmed extirpated by residential subdivision. The status and abundance on the Elkhorn Slough Foundation conservation lands requires field determination. The CNPS (2001) report from Davenport (408C) is probably erroneous, being based on either A. andersonii or A. glutinosa. The species is extensively used in cultivation, especially the cultivar “Sunset” (a hybrid A. pajaroensis x A. hookeri ssp. hookeri), which was originally collected at Manzanita County Park and “Paradise,” collected along Paradise Road.
Exotic, invasive weeds also threaten the species throughout its range, especially jubata grass (Cortaderia jubata), iceplant (Carpobrotus edulis and C. chilense), French broom (Genista monspessulana), and blue gum eucalyptus (Eucalyptus globulus).
Abrams, L. and R. Ferris. 1951. Illustrated Flora of the Pacific States, Vol. 3. Palo Alto. Stanford University Press.
Davis, C. B. 1972. Comparative ecology of the Arctostaphylos andersonii complex. Ph.D. Dissertation, University of California, Davis.
Griffin, J. R. 1978. Maritime chaparral and endemic shrubs of the Monterey Bay region, California. Madroño 25:65-112.
J. B. Roof. 1980. Changing Seasons 1(3):2-31.