Jepson eFlora: Taxon page
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Quercus lobata
VALLEY OAK, ROBLE

Higher Taxonomy
Family: FagaceaeView DescriptionDichotomous Key

Common Name: OAK FAMILY
Habit: Shrub, tree, evergreen or not; monoecious. Leaf: simple, alternate, petioled; margin entire to lobed; stipules small, generally deciduous. Staminate Inflorescence: catkin or stiff spike, many-flowered. Pistillate Inflorescence: 1--few-flowered, generally above staminate inflorescence; involucre bracts many, generally overlapping, flat or cylindric. Staminate Flower: calyx generally 4--6-lobed, minute; petals 0; stamens 4--12+. Pistillate Flower: calyx generally 6-lobed, minute; petals 0; ovary inferior, style branches generally 3. Fruit: 1 nut subtended, partly enclosed by scaly, cup-like involucre or 1--3 nuts subtended, enclosed by spiny, bur-like involucre; mature years 1--2. Seed: generally 1.
Genera In Family: 7 genera, +- 900 species: generally northern hemisphere. Note: Wood of Quercus critical for pre-20th century ship-building, charcoal for metallurgy; some now supply wood (Fagus, Quercus), cork (Quercus suber), food (Castanea, chestnut). Lithocarpus densiflorus moved to Notholithocarpus.
eFlora Treatment Author: John M. Tucker, except as noted
Scientific Editor: Thomas J. Rosatti, Bruce G. Baldwin.
Genus: QuercusView DescriptionDichotomous Key

Common Name: MACDONALD OAK
Habit: Tree 5--15 m, deciduous; trunk bark scaly, +- gray; twigs tomentose. Leaf: 4--7 cm; petiole 3--10 mm; blade oblong to obovate, adaxially glabrous to sparsely hairy, green, +- shiny, abaxially densely appressed-stellate-hairy, +- pale green, tip obtuse to rounded, margin lobes 2--6(8) per leaf, shallow, generally pointed. Fruit: cup 10--20 mm wide, 6--10 mm deep, hemispheric, scales tubercled, canescent; nut 20--35 mm, conic-oblong to ovoid, distally acute to +- obtuse, shell glabrous inside; mature in year 1.
Note: Considered a species by Greene but derived from hybrids involving Quercus pacifica, Quercus lobata, perhaps others; needs study.

Quercus lobata Née
NATIVE
Habit: Tree < 35 m, deciduous; trunk bark thin, scaly, +- light gray. Leaf: 5--12 cm; petiole 5--12 mm; blade obovate, adaxially often +- shiny, dark green, abaxially fine-tomentose, dull to pale green, base wedge-shaped, rounded-gradually tapered, or truncate (subcordate), tip obtuse to rounded, margin lobes 6--10 per leaf, deep (sinuses generally > 1/2 distance lobe tip to midrib), obtuse, generally coarsely 2--3-toothed at tip. Fruit: cup 14--30 mm wide, 10--30 mm deep, hemispheric, scales tubercled; nut 30--50 mm, 12--20 mm wide, generally long-conic, distally acute to +- obtuse, shell glabrous inside; mature in year 1.
Ecology: Slopes, valleys, savanna; Elevation: < 1830 m. Bioregional Distribution: KR, NCoR, CaRF, SNF, s SNH, Teh, GV, SnFrB, SCoR, nw SCo, ChI (Santa Cruz, Santa Catalina islands), WTR, w SnGb. Flowering Time: Mar--Apr Note: Hybridizes with Quercus berberidifolia, Quercus cornelius-mulleri, Quercus douglasii, Quercus engelmannii, Quercus garryana, Quercus john-tuckeri, Quercus pacifica (Quercus ×macdonaldii), Quercus robur.
Synonyms: Quercus lobata f. insperata Jeps.; Quercus lobata f. rarita Jeps.; Quercus lobata var. lobata; Quercus lobata var. turbinata Jeps.; Quercus lobata var. walteri Jeps.
eFlora Treatment Author: John M. Tucker
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botanical illustration including Quercus lobata

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Citation for this treatment: John M. Tucker Quercus lobata, in Jepson Flora Project (eds.) Jepson eFlora, http://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=40663, accessed on November 20, 2017.

Citation for the whole project: Jepson Flora Project (eds.) 2017, Jepson eFlora, http://ucjeps.berkeley.edu/eflora/, accessed on November 20, 2017.


Quercus lobata
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© 2012 Neal Kramer
Quercus lobata
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© 2005 Gary A. Monroe
Quercus lobata
click for enlargement
© 2012 Neal Kramer
Quercus lobata
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© 2007 Neal Kramer
Quercus lobata
click for enlargement
© 2012 Neal Kramer
Quercus lobata
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© 2007 George W. Hartwell

More photos of Quercus lobata in CalPhotos


Geographic subdivisions for Quercus lobata:
KR, NCoR, CaRF, SNF, s SNH, Teh, GV, SnFrB, SCoR, nw SCo, ChI (Santa Cruz, Santa Catalina islands), WTR, w SnGb.
Markers link to CCH specimen records. Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues. Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
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map of distribution 1
(Note: any qualifiers in the taxon distribution description, such as 'northern', 'southern', 'adjacent' etc., are not reflected in the map above, and in some cases indication of a taxon in a subdivision is based on a single collection or author-verified occurence).

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Data provided by the participants of the Consortium of California Herbaria.
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CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa.
Blue line denotes eFlora flowering time.