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Quercus kelloggii

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: OAK
Habit: Evergreen or not. Leaf: stipules small, generally early-deciduous. Staminate Inflorescence: catkins, 1--several, pendent, slender, proximal on twig. Pistillate Inflorescence: in distal leaf axils, short-stalked; flower generally 1. Staminate Flower: stamens 4--10. Pistillate Flower: calyx minute, generally 6-lobed; ovary enclosed by involucre. Fruit: nut 1, partly enclosed by cup-like involucre (cup) with appressed scales (nut and cup = acorn), remnants of perianth and style persistent as small point at tip; scales tubercled to not; mature in years 1 (on younger stems) or 2 (on older stems). Chromosomes: 2n=24.
Species In Genus: +- 600 species: northern hemisphere, to northern South America, India. Etymology: (Latin: ancient name for oak) Note: Many named hybrids; those (3) treated here form widespread populations; most others occur as single individuals, and some but not all of these are mentioned here, under the first parent treated (alphabetically). Reproduction of many species declining due to habitat degradation or loss as well as disease. Quercus robur added, as waif.
eFlora Treatment Author: Thomas J. Rosatti & John M. Tucker

Quercus kelloggii Newb.
Habit: Tree < 35 m, deciduous; trunk bark deeply furrowed, checkered, dark gray-brown to black. Leaf: (6)9--20 cm; petiole (3)10--40 mm; blade widely elliptic, obovate, or +- round, adaxially glabrous, bright green, abaxially finely tomentose, +- glabrous in age, pale green, tip generally acute, bristled, margin lobes generally 6 per leaf, with 1--4 coarse, generally bristle-tipped teeth. Fruit: cup 16--25 mm wide, 15--25 mm deep, generally cup-shaped, scales thin, not tubercled, glabrous to puberulent; nut 20--35 mm, oblong-ovoid, puberulent, distally obtuse to +- rounded, shell woolly inside; mature in year 2.
Ecology: Slopes, valleys, woodland, conifer forest; Elevation: 30--2660 m. Bioregional Distribution: CA-FP (exc GV, SCo, ChI), MP; Distribution Outside California: Oregon, Baja California. Flowering Time: Mid Feb--May Note: Hybridizes with Quercus agrifolia, Quercus parvula var. parvula, Quercus parvula var. shrevei, Quercus wislizeni (Quercus ×morehus Kellogg).
eFlora Treatment Author: Thomas J. Rosatti & John M. Tucker
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botanical illustration including Quercus kelloggii


Citation for this treatment: Thomas J. Rosatti & John M. Tucker 2017. Quercus kelloggii, Revision 2, in Jepson Flora Project (eds.) Jepson eFlora,, accessed on October 16, 2017.

Citation for the whole project: Jepson Flora Project (eds.) 2017. Jepson eFlora,, accessed on October 16, 2017.

Quercus kelloggii
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© 2004 Julie Kierstead Nelson
Quercus kelloggii
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© 2013 Neal Kramer
Quercus kelloggii
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© 2008 Keir Morse
Quercus kelloggii
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© 2014 California Academy of Sciences
Quercus kelloggii
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© 2008 Thomas Stoughton
Quercus kelloggii
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© 2014 Neal Kramer

More photos of Quercus kelloggii in CalPhotos

Geographic subdivisions for Quercus kelloggii:
CA-FP (exc GV, SCo, ChI), MP;
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.
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.