Quercus durata var. gabrielensis

Nixon & C. H. Muller

Novon 4: 392. 1994.

Conservation concernEndemicIllustrated
Treatment appears in FNA Volume 3.

Shrubs, openly branched, scraggly. Leaf-blade moderately cupped, sometimes almost planar; surfaces abaxially with hairs usually 2-4 mm, rays arched, curved or straight, not curly, adaxially green, glossy, usually glabrate or sometimes sparsely stellate-pubescent.


Phenology: Flowering spring.
Habitat: Chaparral on dry, exposed, loose slopes in nonserpentine soils
Elevation: 450-1000 m

Discussion

Of conservation concern.

Quercus durata var. gabrielensis occurs only in Los Angeles County, on the southern slope of the San Gabriel Mountains from La Canada to Pomona. In this area along the lower elevational limits of this variety, occasional intermediates with Q. engelmannii occur [= Q. ×grandidentata Ewan (as species)]. These putative hybrids are large shrubs or small trees with leaves that are persistently woolly on the abaxial surface and have coarse regular teeth. Unfortunately, most of these hybrids have been eliminated by the same uncontrolled growth that has largely expirated Q. engelmannii in this area.

Selected References

None.

Lower Taxa

None.

"thin" is not a number.

paired +  and solitary +
minute-puberulent +
Obtuse (?) +, Rounded (?) +  and Subacute (?) +
Kevin C. Nixon +
Nixon & C. H. Muller +
black;brown;black;brown;gray;white +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (2 cm20 mm <br />0.02 m <br />) +
1.5 cm15 mm <br />0.015 m <br /> (4 cm40 mm <br />0.04 m <br />) +
planar;convex +
7mm;15mm +
reddish-brown +  and brown +
puberulent +  and glabrous +
Globose (?) +  and Ovoid (?) +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
2-6-lobed +
pistillate +, capitate +  and spicate +
starchy +  and fleshy +
turbinate +, cup-shaped +  and hemispheric +
×12-18 +, 4mm +  and 6mm +
multibracteate +, spiny +  and scaly +
450-1000 m +
pistillate +  and staminate +
biennial +, annual +  and maturation +
1-seeded +  and winged +
in groups +  and enclosed +
Chaparral on dry, exposed, loose slopes in nonserpentine soils +
appressed +, semierect +, erect +  and spreading +
0.2 cm2 mm <br />0.002 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
pistillate +, spicate +  and staminate +
tomentulose +  and glabrate +
arranged +  and alternate +
toothed +  and entire +
1.5 cm15 mm <br />0.015 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
cylindric +, ovoid +  and globose +
1 cm10 mm <br />0.01 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
0.1 cm1 mm <br />0.001 m <br /> (0.5 cm5 mm <br />0.005 m <br />) +
Flowering spring. +
straight +  and curved +
stellate-pubescent +  and glabrate +
not curly +
yellowish +  and reddish +
connate +  and distinct +
few-to-many +
tuberculate +
reduced +
anastomosing +, branching +  and unbranched +
yellowish +  and grayish +
impressed +, obscure +  and prominent +
Conservation concern +, Endemic +  and Illustrated +
inconspicuous +
distinct +
subulate +  and dilated +
enlarged +
0.1 cm1 mm <br />0.001 m <br /> (0.4 cm4 mm <br />0.004 m <br />) +
Quercus dumosa var. bullata +  and Quercus dumosa var. revoluta +
Quercus durata var. gabrielensis +
Quercus durata +
variety +
spheric +  and ovoid terete or angled +
bristle-tipped +
yellowish +  and gray +
0.1 cm1 mm <br />0.001 m <br /> (0.3 cm3 mm <br />0.003 m <br />) +
tomentulose +
shrub +  and scraggly +