Quercus douglasii Hook. & Arn.

Iron oak (en)

Species

Angiosperms > Fagales > Fagaceae > Quercus

Characteristics

Trees , deciduous, with single trunks, sometimes with few to several trunks. Bark gray, scaly. Twigs reddish or yellowish, ca. 2 mm, densely or sparsely puberulent, occasionally glabrate with age. Buds reddish brown, rarely yellowish, broadly ovoid to rarely subglobose, (2-)3-5 mm; scales glabrous except for ciliate margins, sometimes sparsely or densely pubescent. Leaves: petiole blue-green, 2-6 mm. Leaf blade obovate or elliptic, oblong or oblanceolate, (20-)40-60(-80) × (15-)20-30(-40) mm, base rounded-attenuate or rounded, rarely cuneate, margins shallowly lobed or irregularly toothed, sometimes entire, lobes mucronate or rounded, secondary veins 6-10 on each side, apex rounded, rarely moderately acute; surfaces abaxially light green or blue-green, waxy, with scattered to crowded, semi-erect, (2-)4-6(-8)-rayed stellate hairs usually 0.2-0.6 mm diam. or larger, adaxially blue-green, glaucous or grayish, vestiture similar to abaxial surface. Acorns subsessile, solitary; cup hemispheric or cup-shaped, rarely deeper, 5-10 mm deep × 10-15 mm wide, enclosing only base of nut, scales thin and not tuberculate to strongly and irregularly tuberculate, particularly toward base of cup; nut thin-walled, fusiform or subcylindric, 20-30 × 10-16 mm. Cotyledons distinct. 2 n = 24.
More
A large shrub or tree. It grows 21 m high and spreads 6 m wide. It loses its leaves during the year. It has a rounded crown. The bark is thin, grey and scaly. The leaves are bluish and have lobes along the edges. The fruit are cone shaped acorns. They are small and in a shallow hairy cup. The acorns are 2-3 cm long.
Life form perennial
Growth form tree
Growth support free-standing
Foliage retention deciduous
Sexuality monoecy
Pollination anemogamy
Spread -
Mature width (meter) 4.0
Mature height (meter) 8.5 - 12.0
Root system -
Rooting depth (meter) 0.65
Root diameter (meter) -
Flower color
Blooming months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Fruit color -
Fruiting months
JanFebMar
AprMayJun
JulAugSep
OctNovDec
Nitrogen fixer -
Photosynthetic pathway c3

Environment

Dry soils in valleys, rolling hills and lower mountain slopes; at elevations up to 1,350 metres, often forming extensive stands.
More
It is a temperate plant. Kyneton Botanical Gardens. It suits hardiness zones 6-11.
Light 5-8
Soil humidity 2-6
Soil texture 2-4
Soil acidity 2-7
Soil nutriment -
Hardiness (USDA) 6-8

Usage

The acorns are ground into a meal, and used to make soup, bread or biscuits. They are also dried, pounded and leached. They are stored for later use.
Uses dye fiber fuel medicinal wood
Edible seeds
Therapeutic use Throat Aid (leaf), Burn Dressing (unspecified), Dermatological Aid (unspecified), Eye Medicine (unspecified), Cancer (unspecified)
Human toxicity -
Animal toxicity -

Cultivation

Can be grown by seedlings.
Mode seedlings
Germination duration (days) 120 - 365
Germination temperacture (C°) 10
Germination luminosity -
Germination treatment -
Minimum temperature (C°) -18
Optimum temperature (C°) -
Size -
Vigor -
Productivity -

Images

Leaf

Quercus douglasii leaf picture by ken harrison (cc-by-sa)
Quercus douglasii leaf picture by ken harrison (cc-by-sa)
Quercus douglasii leaf picture by ken harrison (cc-by-sa)

Distribution

Quercus douglasii world distribution map, present in United States of America

Conservation status

Quercus douglasii threat status: Least Concern

Identifiers

LSID urn:lsid:ipni.org:names:296074-1
WFO ID wfo-0000290545
COL ID 4R4TP
BDTFX ID -
INPN ID -
Wikipedia (EN) Link
Wikipedia (FR) Link

Synonyms

Quercus gambelii Quercus ransomii Quercus douglasii Quercus oblongifolia var. brevilobata Quercus douglasii var. ransomii