Envoy at 07:58, 28 July 2007

2007-07-28T07:58:18Z

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{{Taxobox
| color = lightgreen
| name = Tanoak
| status = {{StatusData}}
| image = Tanoak acorns.jpg
| image_width = 250px
| image_caption = Tanoak acorns <br>([[United States|U.S.]] 5 cent coin, 21 mm diameter, for scale)
| regnum = [[Plant]]ae
| divisio = [[flowering plant|Magnoliophyta]]
| classis = [[dicotyledon|Magnoliopsida]]
| ordo = [[Fagales]]
| familia = [[Fagaceae]]
| genus = ''[[Lithocarpus]]''
| species = '''''L. densiflorus'''''
| binomial = ''Lithocarpus densiflorus''
| binomial_authority = ([[William Jackson Hooker|Hook.]] & [[George Arnott Walker Arnott|Arn.]]) [[Alfred Rehder|Rehd.]]
}}

The '''Tanoak''' or '''Tanbark-oak''' (''Lithocarpus densiflorus'') is an [[evergreen]] [[tree]] in the beech family [[Fagaceae]], native to the western [[United States]], in [[California]] as far south as the [[Transverse Ranges]] and north to southwest [[Oregon]]. It can reach 40 m tall (though 15–25 m is more usual) in the [[California Coast Ranges]], and can have a trunk diameter of 60–190 cm.

Although currently included in the genus ''[[Lithocarpus]]'', genetic evidence (Manos et al. 2001) suggests it is only distantly related to the rest of the genus (all found in southeast [[Asia]]).

The [[leaf|leaves]] are alternate, 7–15 cm long, with toothed margins and a hard, leathery texture, and persist for 3–4 years. At first they are covered in dense orange-brown scurfy hairs on both sides, but those on the upper surface soon wear off, those on the under surface persisting longer but eventually wearing off too.

The [[seed]] is a [[nut (fruit)|nut]] 2–3 cm long and 2 cm diameter, very similar to an [[oak]] [[acorn]], but with a very hard, woody nut shell more like a [[hazel]] nut. The nut sits in a cup during its 18-month maturation; the outside surface of the cup is rough with short spines. The nuts are produced in clusters of a few together on a single stem. The nut kernel is very bitter, and is inedible for people without extensive leaching, although [[squirrel]]s eat them. Some California [[Native Americans in the United States|Indians]] prefer this nut to those of many [[Quercus]] acorns because it stores well due to the comparatively high tannin content.

Members of populations in interior California (in the northern [[Sierra Nevada (U.S.)|Sierra Nevada]]) and the [[Klamath Mountains]] into southwest Oregon are smaller, rarely exceeding 3 m in height and often shrubby, with smaller leaves, 4–7 cm long; these are separated as '''Dwarf Tanoak''' ''Lithocarpus densiflorus'' var. ''echinoides''. The variety intergrades with the type in northwest California and southwest Oregon. Tanoak does grow on [[serpentine soil]]s as a shrub.

==Uses==
The name Tanoak refers to its [[tannin]]-rich bark, used in the past for tanning [[leather]] before the use of modern synthetic tannins.

Tanoak is one of the species most seriously affected by [[Sudden Oak Death]] (''Phytophthora ramorum''), with high mortality reported over much of the species' range.

==References==
*[http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233500750 Flora of North America: ''Lithocarpus densiflorus'']
*Manos, P. S., Zhou, Z-K., & Cannon, C. H. (2001). ''Int. J. Plant Sci.'' 162(6): 1361–1379 [http://www.faculty.biol.ttu.edu/cannon/pdfs/manos01.pdf pdf file]
[[Category:Fagaceae]]
[[Category:Trees of California]]

Tanoak - Revision history

Envoy at 07:58, 28 July 2007