The Lithocarpus Densiflorus
is commonly known as Tan Oak
, as well as Tanoak< Go Back
A major component of coastal mixed evergreen forests, tanoak is
distributed from the Cascade Mountains of southwestern Oregon southward
through the Klamath Mountains and California Coast Ranges to Ventura
]. In northern California, tanoak ranges inland to the
lower slopes of Mount Shasta and occurs intermittently along the west
slope of the Sierra Nevada as far south as Mariposa County [31
stands are locally abundant in Butte and Yuba Counties [13
inventories indicate that this hardwood comprises the dominant cover
type over at least 861,000 acres (350,700 ha) in California [4
Shrub tanoak (var. echinoides) occurs in chaparral communities
throughout the mountains of northern California and southern Oregon,
becoming particularly abundant in the vicinity of Mount Shasta
]. Scattered populations also occur in the southern Coast
Ranges and in the central Sierra Nevada [34
The currently accepted scientific name of tanoak is Lithocarpus
densiflorus (Hook. & Arn.) Rehd. [56
]. Tanoak is the only North
American representative of a large Asian genus. The genus Lithocarpus
is considered a link between true oaks (Quercus) and the chinquapins
and chestnuts (Castanopsis and Castanea), possessing characteristics
of each [34
]. A shrubby growth form of tanoak, commonly known as
shrub tanoak, has been recognized at the varietal level as Lithocarpus
densiflorus var. echinoides (R. Br.) Ambrams.[17
]. Unless stated
otherwise, this discussion pertains to the typical variety, L.
densiflorus var. densiflorus.
Self-perpetuating stands of tanoak are indicative of climax conditions
in a number of communities within evergreen hardwood , mixed
evergreen [1,10,55], redwood (Sequoia sempervirens) [47,55], and mixed
conifer forests .
Within mixed evergreen forests in southwestern Oregon, Atzet 
describes climax tanoak communities associated with warm, moist sites
along the lower slopes of the Siskiyou Mountains. Even though most
stands are currently dominated by a Douglas-fir (Pseudotsuga menziesii)
overstory, Douglas-fir is a fire-maintained, seral component within
these stands. Climax understory dominants within the tanoak series may
include vine maple (Acer circinatum), Cascade holly grape (Berberis
nervosa), poison-oak (Toxicodendron diversilobum), salal (Gaultheria shallon),
vanilla leaf (Achlys triphylla), common prince's-pine (Chimaphila
umbellata), and twinflower (Linnaea borealis).
< Go Back
Much of the information presented here is attributed to:
McMurray, Nancy E. 1989. Lithocarpus densiflorus. In: Fire Effects Information System, [Online].
U.S. Department of Agriculture, Forest Service,
Rocky Mountain Research Station, Fire Sciences Laboratory (Producer). Available at USDA Forest Service.