- Author: Robert J Keiffer
Here at the UC Hopland Research & Extension Center in southeast Mendocino County there exists a live oak of-sorts that is unknown to many. Many locals familiar with oaks in the North Coast area are familiar with coast live oak, interior live oak, and canyon live oak ... but few are acquainted with the Shreve or Shreve's Oak (Quercus parvula E. Greene, variety shrevei (C.H. Muller) Nixon. Any tree with a scientific name that long must be complex.
The late UC Davis Professor of Plant Science & Center for Plant Diversity - John Tucker (1916-2008) - spent the last years of his life working on a manuscript to describe Northern California populations of Shreve's Oak. The plant's characteristics and distribution had held his interest for more than a decade. Just prior to his passing, he finished a new version of the oak treatment for the revision of the Jepson Manual: Higher Plants of California,
which includes Shreve's oak.
The Shreve oak is the tree-like mainland variety of the shrubby, primarily insular Santa Cruz Island Oak (Q. parvula var. parvula). Field research has shown the Shreve's oak to occur along the California coastal counties from the Santa Lucia Mountains northward into the Coast Range of Mendocino County. The species Q.parvula, once thought to only occur on Santa Cruz Island, is now known to exist in eleven counties.
Field work by Tucker and others have documented hybrids with Coast Live Oak(Q.agrifolia) and with Interior Live Oak (Q. wislizeni). Characteristics for Shreve Oak include: smooth leaf margins, or if spined the "spines" are abrupt and needle-like, olive-green coloration on the underside of the leaf, a long petiole (leaf stem) up to 25 mm long, and a cylindric acorn shape instead of tapered to a point.