Jepson eFlora: Taxon page
Vascular Plants of California
Key to families | Table of families and genera
Previous taxon Index to accepted names and synonyms:
| A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z |
Next taxon


Quercus pacifica
ISLAND SCRUB OAK


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
Reference: Manos et al. 1999 Molec Phylogen Evol 12:333--349
Unabridged Reference: Cottam, W. P., J. M. Tucker, & F. S. Santamour. 1982. Oak hybridization at the University of Utah. State Arboretum of Utah Publication No. 1. Salt Lake City; Hardin, J. W. 1975. Hybridization and introgression in Quercus alba. Journal of the Arnold Arboretum 56: 336--363; Manos, P. S., Doyle, J. J., & Nixon, K. C. 1999. Phylogeny, biogeography, and processes of molecular differentiation of Quercus subgenus Quercus (Fagaceae). Molec Phylogen Evol 12: 333--349.
Quercus pacifica Nixon & C.H. Mull.
NATIVE
Habit: Shrub to 2 m (small tree to 5 m), generally evergreen; twigs finely hairy, +- red or +- brown, glabrous in age, gray. Leaf: 1.5--4 cm; petiole 2--5 mm; blade obovate or oblong, adaxially green, abaxially light green with minute appressed stellate hairs, in age glabrous, base gradually tapered, wedge-shaped, or rounded, tip generally rounded, margin entire, wavy, or +- toothed, teeth generally mucronate. Fruit: cup 8--20 mm wide, 5--15 mm deep, hemispheric to top-shaped, scales moderately to strongly tubercled; nut 20--30 mm, ovoid to cylindric, distally acute to +- obtuse, shell glabrous inside; mature in year 1.
Ecology: Slopes, ridges, canyons, chaparral, coastal scrub, oak woodland, pine forest; Elevation: < 610 m. Bioregional Distribution: ChI (Santa Cruz, Santa Rosa, Santa Catalina islands). Flowering Time: Mar--Apr Note: Hybridizes with Quercus lobata.
Jepson eFlora Author: Thomas J. Rosatti & John M. Tucker
Reference: Manos et al. 1999 Molec Phylogen Evol 12:333--349
Unabridged Reference: Cottam, W. P., J. M. Tucker, & F. S. Santamour. 1982. Oak hybridization at the University of Utah. State Arboretum of Utah Publication No. 1. Salt Lake City; Hardin, J. W. 1975. Hybridization and introgression in Quercus alba. Journal of the Arnold Arboretum 56: 336--363; Manos, P. S., Doyle, J. J., & Nixon, K. C. 1999. Phylogeny, biogeography, and processes of molecular differentiation of Quercus subgenus Quercus (Fagaceae). Molec Phylogen Evol 12: 333--349.
Jepson Online Interchange
Listed on CNPS Rare Plant Inventory

Previous taxon: Quercus ×macdonaldii
Next taxon: Quercus palmeri

Name Search

Botanical illustration including Quercus pacifica

botanical illustration including Quercus pacifica

Contact/Feedback

Citation for this treatment: Thomas J. Rosatti & John M. Tucker 2014, Quercus pacifica, in Jepson Flora Project (eds.) Jepson eFlora, Revision 2, http://ucjeps.berkeley.edu/eflora/eflora_display.php?tid=80203, accessed on September 18, 2019.

Citation for the whole project: Jepson Flora Project (eds.) 2019, Jepson eFlora, http://ucjeps.berkeley.edu/eflora/, accessed on September 18, 2019.

Quercus pacifica
click for enlargement
© 2012 Chris Winchell
Quercus pacifica
click for enlargement
© 2012 Chris Winchell
Quercus pacifica
click for enlargement
© 2015 Keir Morse
Quercus pacifica
click for enlargement
© 2001 Tony Morosco
Quercus pacifica
click for enlargement
© 2014 Steve Matson
Quercus pacifica
click for enlargement
© 2012 Chris Winchell

More photos of Quercus pacifica in CalPhotos



Geographic subdivisions for Quercus pacifica:
ChI (Santa Cruz, Santa Rosa, Santa Catalina islands).
MAP CONTROLS
1. You can change the display of the base map and layers by clicking on the layer control box in the upper right-hand corner.
2. California county polygons can be turned off and on in the layer control box.
3. Filling of Jepson subdivision polygons can be turned off and on in the layer control box.
4. Marker clustering can be turned on by clicking this link:      Marker Clustering ON
WARNING: This page may load slowly if there are large numbers of specimens in the database.
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).





 

View elevation by latitude chart


Data provided by the participants of the  Consortium of California Herbaria.
MAP LEGEND
View all CCH records
All markers link to CCH specimen records. The original determination is shown in the popup window.
Blue markers indicate specimens that map to one of the expected Jepson geographic subdivisions (see left map). Purple markers indicate specimens collected from a garden, greenhouse, or other non-wild location.
Yellow markers indicate records that may provide evidence for eFlora range revision or may have georeferencing or identification issues.
READ ABOUT YELLOW FLAGS


CCH collections by month

Duplicates counted once; synonyms included.
Species do not include records of infraspecific taxa, if there are more than 1 infraspecific taxon in CA.
Blue line denotes eFlora flowering time.