Quercus vacciniifolia |
Quercus tomentella |
|
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huckleberry oak |
Channel Island oak, island live oak, island oak |
|
Habit | Shrubs, low spreading to often prostrate, to 1.5 m. Twigs branching at 45° angles or less, reddish brown, 1-1.5 mm diam., flexible, glabrous to sparsely pubesent. | 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 oblong-ovate, 10-35 × 7-15 mm, flat, thin, leathery, base slightly rounded to acute, secondary veins inconspicuous, 6-8 pairs, branching at 45-60° angles, with weakly thickened cell walls, margins entire or indistinctly and irregularly mucronately toothed, apex acute or rarely obtuse; surfaces abaxially whitish green with waxy layer, glabrous or slightly pubescent with stellate hairs, adaxially dull gray-green, glabrous or sparsely pubescent with stellate hairs. |
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 saucer-shaped to slightly turbinate, 3-4 mm deep × 10-15 mm wide, scales appressed, slightly embedded, moderately silvery brown-pubescent; nut ovoid, 8-17 × 5-10 mm, apex acute; nut scar to 3 mm diam. |
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, 2.5 mm, scales brown with ciliate margins. |
buds conic, 7-10 mm, scales brown with ciliate margins. |
Quercus vacciniifolia |
Quercus tomentella |
|
Phenology | Flowering in early summer. | Flowering in spring, occasionally in fall. |
Habitat | Dry ridges, steep slopes, and rocky areas from montane coniferous zone to near treeline | Lower portions of steep canyons and occasionally ridge tops |
Elevation | 900-2800 m (3000-9200 ft) | 100-650 m (300-2100 ft) |
Distribution |
CA; NV; OR
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CA; Mexico (Baja California and on Guadalupe Island)
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Discussion | Typical high-elevation populations in the Sierra Nevada of California can be distinguished from all shrubby forms of Quercus chrysolepis by the absence of glandular trichomes and by thin cups with small nut-attachment scars. At lower elevations in northern California and southwestern Oregon, secondary contact with Q. chrysolepis has resulted in the formation of hybrids. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
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. | FNA vol. 3. |
Parent taxa | Fagaceae > Quercus > sect. Protobalanus | Fagaceae > Quercus > sect. Protobalanus |
Sibling taxa | ||
Name authority | Hittell: Resources Calif. 101. (1863) — (as vaccinifolia) | Engelmann: Trans. Acad. Sci. St. Louis, 3: 393. (1877) |
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