FNA: Quercus tomentella

	Quercus tomentella
	Channel Island oak, island live oak, island oak
Habit	Trees, to 20 m. Twigs branching at 45° angles, reddish brown, 3-4 mm diam., somewhat rigid, densely tomentose, persistent into 2d year.
Leaves	blade wavy or distinctly concave, oblong-lanceolate or elliptic, acuminate, (30-)70-10(-120) × 25-40 mm, leathery and brittle, base obtuse to cordate, secondary veins 8-10(-12) pairs, branching at 45-50° angles, strongly pinnate, raised abaxially, often sunken adaxially, margins often strongly revolute, with slightly thickened cell walls, entire or crenate to dentate with mucronate teeth, apex rounded or acute, mucronate; surfaces abaxially densely tomentose with whitish nonglandular hairs, midrib pilose, adaxially glossy dark green, sparsely pubescent.
Acorns	solitary or rarely paired; cup shallowly cup-shaped, 4-8 mm deep × 15-30 mm wide, scales laterally connate, appressed, deeply imbedded in tomentum, with only thin, brown, elongated apices visible, tuberculate, densely whitish brown tomentose throughout; nut ovoid, 20-30 × 15-20 mm, apex rounded.
Terminal	buds conic, 7-10 mm, scales brown with ciliate margins.

	Quercus tomentella
Phenology	Flowering in spring, occasionally in fall.
Habitat	Lower portions of steep canyons and occasionally ridge tops
Elevation	100-650 m (300-2100 ft)
Distribution	CA; Mexico (Baja California and on Guadalupe Island) [WildflowerSearch map] [BONAP county map]
Discussion	The insular endemic Quercus tomentella is a relict as evidenced by its widespread representation in mainland late Tertiary fossil floras. Hybridization with Q. chrysolepis is apparent on the Channel Islands: Santa Catalina, Santa Cruz, and possibly San Clemente and Anacapa. Putative hybrids have been observed in narrow zones of contact on the islands of Santa Cruz and Santa Catalina. On those islands, taxonomically distinct individuals of Q. chrysolepis occur at the highest elevations, whereas Q. tomentella generally is found in moist canyons at lower elevations. Populations of Channel Island oak are in decline because of overgrazing and poor seedling recruitment. The greatest number of populations occur on Santa Rosa Island, and those are taxonomically and genetically noteworthy because Q. chrysolepis apparently is absent from the island. (Discussion copyrighted by Flora of North America; reprinted with permission.)
Source	FNA vol. 3.
Parent taxa	Fagaceae > Quercus > sect. Protobalanus
Sibling taxa	Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chihuahuensis, Q. chrysolepis, Q. coccinea, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. havardii, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. incana, Q. inopina, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. macrocarpa, Q. margarettae, Q. marilandica, Q. michauxii, Q. minima, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pacifica, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robur, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. toumeyi, Q. turbinella, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii
Name authority	Engelmann: Trans. Acad. Sci. St. Louis, 3: 393. (1877)
Web links	Local floras: CA Local Web sites: CalFlora, CalPhotos WildflowerSearch iNaturalist (observations) USDA Plants Database LBJ Wildflower Center SEINet Plants of the World Online Encyclopedia of Life Wikipedia Google Image Search

Quercus tomentella

Channel Island oak, island live oak, island oak

Habit

Trees, to 20 m. Twigs branching at 45° angles, reddish brown, 3-4 mm diam., somewhat rigid, densely tomentose, persistent into 2d year.

Leaves

blade wavy or distinctly concave, oblong-lanceolate or elliptic, acuminate, (30-)70-10(-120) × 25-40 mm, leathery and brittle, base obtuse to cordate, secondary veins 8-10(-12) pairs, branching at 45-50° angles, strongly pinnate, raised abaxially, often sunken adaxially, margins often strongly revolute, with slightly thickened cell walls, entire or crenate to dentate with mucronate teeth, apex rounded or acute, mucronate;

surfaces abaxially densely tomentose with whitish nonglandular hairs, midrib pilose, adaxially glossy dark green, sparsely pubescent.

Acorns

solitary or rarely paired;

cup shallowly cup-shaped, 4-8 mm deep × 15-30 mm wide, scales laterally connate, appressed, deeply imbedded in tomentum, with only thin, brown, elongated apices visible, tuberculate, densely whitish brown tomentose throughout;

nut ovoid, 20-30 × 15-20 mm, apex rounded.

Terminal

buds conic, 7-10 mm, scales brown with ciliate margins.

Quercus tomentella

Phenology

Flowering in spring, occasionally in fall.

Habitat

Lower portions of steep canyons and occasionally ridge tops

Elevation

100-650 m (300-2100 ft)

Distribution

CA; Mexico (Baja California and on Guadalupe Island)

[WildflowerSearch map]

[BONAP county map]

Discussion

The insular endemic Quercus tomentella is a relict as evidenced by its widespread representation in mainland late Tertiary fossil floras. Hybridization with Q. chrysolepis is apparent on the Channel Islands: Santa Catalina, Santa Cruz, and possibly San Clemente and Anacapa. Putative hybrids have been observed in narrow zones of contact on the islands of Santa Cruz and Santa Catalina. On those islands, taxonomically distinct individuals of Q. chrysolepis occur at the highest elevations, whereas Q. tomentella generally is found in moist canyons at lower elevations. Populations of Channel Island oak are in decline because of overgrazing and poor seedling recruitment. The greatest number of populations occur on Santa Rosa Island, and those are taxonomically and genetically noteworthy because Q. chrysolepis apparently is absent from the island.

(Discussion copyrighted by Flora of North America; reprinted with permission.)

Source

FNA vol. 3.

Parent taxa

Fagaceae > Quercus > sect. Protobalanus

Sibling taxa

Q. acerifolia, Q. agrifolia, Q. ajoensis, Q. alba, Q. arizonica, Q. arkansana, Q. austrina, Q. berberidifolia, Q. bicolor, Q. boyntonii, Q. buckleyi, Q. carmenensis, Q. chapmanii, Q. chihuahuensis, Q. chrysolepis, Q. coccinea, Q. cornelius-mulleri, Q. depressipes, Q. douglasii, Q. dumosa, Q. durata, Q. ellipsoidalis, Q. emoryi, Q. engelmannii, Q. falcata, Q. fusiformis, Q. gambelii, Q. garryana, Q. geminata, Q. georgiana, Q. graciliformis, Q. gravesii, Q. grisea, Q. havardii, Q. hemisphaerica, Q. hinckleyi, Q. hypoleucoides, Q. ilicifolia, Q. imbricaria, Q. incana, Q. inopina, Q. intricata, Q. john-tuckeri, Q. kelloggii, Q. laceyi, Q. laevis, Q. laurifolia, Q. lobata, Q. lyrata, Q. macrocarpa, Q. margarettae, Q. marilandica, Q. michauxii, Q. minima, Q. mohriana, Q. montana, Q. muehlenbergii, Q. myrtifolia, Q. nigra, Q. oblongifolia, Q. oglethorpensis, Q. pacifica, Q. pagoda, Q. palmeri, Q. palustris, Q. phellos, Q. polymorpha, Q. prinoides, Q. pumila, Q. pungens, Q. robur, Q. robusta, Q. rubra, Q. rugosa, Q. sadleriana, Q. shumardii, Q. similis, Q. sinuata, Q. stellata, Q. tardifolia, Q. texana, Q. toumeyi, Q. turbinella, Q. vacciniifolia, Q. vaseyana, Q. velutina, Q. viminea, Q. virginiana, Q. wislizenii

Name authority

Engelmann: Trans. Acad. Sci. St. Louis, 3: 393. (1877)

Web links

Unless otherwise noted, all data comes from the online version of the Flora of North America, who have made most of their content available via a Creative Commons license (CC BY 4.0).

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Quercus tomentella

Quercus tomentella