Quercus depressipes

Trelease

Mem. Natl. Acad. Sci. 20: 90. 1924.

Common names: Depressed oak
Illustrated
Synonyms: Quercus bocoynensis C. H. Muller
Treatment appears in FNA Volume 3.

Shrubs, evergreen or subevergreen, low, to 1 m, often forming dense thickets, rhizomatous. Bark gray, scaly. Twigs tan-brown, becoming reddish gray, 1-1.5 mm diam., glabrate or hairy. Buds tan or brown, subglobose, 1-1.5 mm, glabrate or scales inconspicuously ciliate. Leaves: petiole 1-2 mm, rarely longer. Leaf-blade oblong to elliptic, 10-25 (-60) × 8-25 mm, thick, leathery, base moderately to deeply cordate, petiole strongly depressed in basal sinus, margins inconspicuously toothed in distal 1/2, rarely entire, sometimes sublobate, somewhat revolute, secondary-veins 5 or 6 on each side with few intermediates, branching, apex broadly rounded to subacute; surfaces abaxially dull gray-green or glaucous, completely glabrous or with a few stellate hairs on midrib, adaxially similar to abaxial surface, secondary-veins somewhat raised on both surfaces. Acorns paired on peduncle 7-15 mm; cup 4-7 mm deep × 8-13 mm wide, goblet-shaped, enclosing 1/4-1/2 nut, base somewhat constricted or rounded, scales moderately tuberculate, proximally densely gray-tomentose, tips rather closely appressed, reddish-brown, abaxially glabrous, ciliate; nut tan-brown, elliptic to ovoid or globose, to 10-15 × 10-11 mm, apex rounded, glabrous. Cotyledons connate.


Phenology: Flowering spring.
Habitat: Grassland and open wooded slopes
Elevation: 2100-2600 m

Distribution

V3 880-distribution-map.gif

Tex., Mexico (Chihuahua), Mexico (Durango), Mexico (and Zacatecas)

Discussion

Quercus depressipes enters the United States in only one population on the highest portion of Mt. Livermore in trans-Pecos Texas; it has a wider distribution in the dry altiplano of northern Mexico. Its most distinctive characteristics are the combination of dwarf clonal habit, small glaucous leaves without spinose teeth, and connate cotyledons. In northern Mexico, it hybridizes locally with Q. rugosa.

Selected References

None.

Lower Taxa

None.
... more about "Quercus depressipes"
rounded +, broadly rounded +  and subacute +
Kevin C. Nixon +
Trelease +
rounded;cordate +
constricted +
brown +  and tan +
subglobose +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
2-6-lobed +
pistillate +, capitate +  and spicate +
Depressed oak +
starchy +  and fleshy +
goblet--shaped +
×8-13 +, 4mm +  and 7mm +
multibracteate +, spiny +  and scaly +
Tex. +, Mexico (Chihuahua) +, Mexico (Durango) +  and Mexico (and Zacatecas) +
2100-2600 m +
pistillate +  and staminate +
biennial +, annual +  and maturation +
1-seeded +  and winged +
in groups +  and enclosed +
Grassland and open wooded slopes +
pistillate +, spicate +  and staminate +
tomentulose +  and glabrate +
2.5 cm25 mm <br />0.025 m <br /> (6 cm60 mm <br />0.06 m <br />) +
1 cm10 mm <br />0.01 m <br /> (2.5 cm25 mm <br />0.025 m <br />) +
oblong +  and elliptic +
thick;8mm;25mm +
arranged +  and alternate +
sublobate +  and entire +
tan-brown +
1 cm10 mm <br />0.01 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
1/4 +  and 1/2 +
elliptic +  and ovoid or globose +
1 cm10 mm <br />0.01 m <br /> (1.1 cm11 mm <br />0.011 m <br />) +
0.7 cm7 mm <br />0.007 m <br /> (1.5 cm15 mm <br />0.015 m <br />) +
depressed +
0.1 cm1 mm <br />0.001 m <br /> (0.2 cm2 mm <br />0.002 m <br />) +
Flowering spring. +
Mem. Natl. Acad. Sci. +
connate +  and distinct +
gray-tomentose +
few-to-many +
tuberculate +
reduced +
anastomosing +, branching +  and unbranched +
Illustrated +
inconspicuous +
distinct +
subulate +  and dilated +
enlarged +
with a few stellate hairs +, glabrous +  and glaucous +
Quercus bocoynensis +
Quercus depressipes +
Quercus sect. Quercus +
species +
spheric +  and ovoid terete or angled +
reddish-brown +
bristle-tipped +
reddish gray +  and tan-brown +
0.1 cm1 mm <br />0.001 m <br /> (0.15 cm1.5 mm <br />0.0015 m <br />) +
hairy +  and glabrate +
subevergreen +  and evergreen +