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Quercus taxonomy
Quercus lyrata Walter
EOL Text
More info for the term: tree
Overcup oak is a deciduous, native tree [12]. Mature trees usually
range from 60 to 90 feet (18-27 m), and 24 to 30 inches (61-76 cm)
d.b.h. Maximum height is rarely over 100 feet (30 m) [34,39]. The bark
has thick, irregular plates or ridges covered with inner scales. The
root system is usually shallow and saucer shaped. Seedling taproots are
usually replaced by a lateral root system [39]. Mature crown leaves
range from 5 to 8.5 inches (13-21.5 cm) in length and are usually five-
to nine-lobed [12]. The acorns range from 0.48 to 1 inch (12-25 mm) in
length, and are nearly globose to broadly ovoid. The acorn cup
covers two-thirds to nearly all of the acorn, with acute scales [7].
Oaks usually grow slowly for the first 10 to 15 years; growth rates
become more rapid thereafter [21]. The national champion overcup oak
for 1976 was in South Carolina; it measured 22 feet (6.7 m) in
circumference, was 123 feet (37 m) tall, and had a 48-foot (14.6-m)
crown spread [12]. The largest overcup oak (ranked by point system in
1990) was found in Texas. It was 51.1 inches (129.8 cm) in diameter,
160.53 inches (13.37 m) in circumference, and 114 feet tall (34.7 m)
[29]. Overcup oaks can live to 400 years of age [39].
DeSelm and Clebsch [5] reported that mature overcup oak trees are
somewhat resistant to direct mortality from fire, but barely survived
two to five prescribed fires between 1964 and 1988 [5].
In overcup oak, even minor injuries from fire can create avenues of
infection for heart rots, which can cause decadence and/or mortality
years later [39,41].
Population Differences Wide differences in quality of overcup oak occur over its range-generally the better quality is found in its northern and eastern range. These differences, however, are probably due to response to site and seasonal flooding patterns rather than to genetic differences. Limited studies of juvenile variation within a small geographic area have not provided any evidence of genetic variation among localities.
Hybrids Quercus lyrata hybridizes with Q. alba; Q. durandii; Q. bicolor (Q. x humidicola Palmer), Q. macrocarpa (Q. x megaleia Laughlin); Q. michauxii (Q. x tottenii Melvin); Q. stellata (Q. x sterrettii Trel.); and Q. virginiana (Q. x comptoniae Sarg.) (8). A cross between Q. lyrata and Q. virginiana is reported to be promising for propagation and dissemination (10). This hybrid is a semievergreen and has a higher growth rate than either parent. However, its vegetative propagation has presented problems.
More info for the term: swamp
The currently accepted scientific name of overcup oak is Quercus
lyrata Walt. [18,28]. Two accepted forms are differentiated [7]:
Q. l. forma lyrata, with hairy undersurfaces,
Q. l. forma viridis Trel., with scattered hairs on leaf undersurfaces.
Overcup oak hybridizes with many other oaks in the white oak subgenus
(Quercus) including white oak (Q. alba), swamp white oak (Q. bicolor),
Durand oak (Q. durandii), bur oak (Q. macrocarpa), swamp chestnut oak
(Q. michauxii), post oak (Q. stellata), and live oak (Q. virginiana)
[28]. Overcup oak is genetically most similar to post oak, based on
electrophoretic evidence [14].
Trees , deciduous, to 20 m. Bark light gray, tinged with red, with thick plates underlying scales. Twigs grayish or reddish, (2-)3(-4) mm diam., villous, soon glabrate. Buds 3 mm, gray-puberulent. Leaves: petiole 8-20(-25) mm. Leaf blade obovate or broadly obovate, 100-160(-200) × 50-100(-120) mm, base narrowly cuneate to acute, margins moderately to deeply lobed, lobes somewhat to sharply angular or spatulate, often with 2-3 teeth, sinuses nearly to midrib, secondary veins arched, divergent, (3-)5-7 on each side, apex broadly rounded or ovate; surfaces abaxially light green or somewhat glaucous, tomentose, tomentum persisting or soon falling, adaxially dark green or dull gray, sparsely puberulent to glabrate. Acorns 1-2 on axillary peduncles to 40 mm; cup goblet-shaped, burlike, or spheroid, 15-20 mm deep × 20-30 mm wide, usually completely enclosing nut or merely apex visible, rarely enclosing only 1/2 nut, orifice smaller than nut diameter, often splitting irregularly at maturity, scales closely appressed, especially about margin, laterally connate, broadly triangular, keeled-tuberculate, finely grayish tomentose; nut light brown or grayish, ovoid-ellipsoid or oblong, (15-)25-50 × (10-)20-40 mm, finely puberulent or floccose. Cotyledons distinct.
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| Rights holder/Author | eFloras.org Copyright © Missouri Botanical Garden |
| Source | http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233501057 |
More info for the terms: root sucker, secondary colonizer
Tree with adventitious-bud root crown/soboliferous species root sucker
Secondary colonizer - off-site seed
United States
Rounded National Status Rank: N5 - Secure
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| Rights holder/Author | NatureServe |
| Source | http://explorer.natureserve.org/servlet/NatureServe?searchName=Quercus+lyrata |
Quercus bicolor Willdenow var. lyrata (Walter) Dippel
| License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
| Rights holder/Author | eFloras.org Copyright © Missouri Botanical Garden |
| Source | http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=233501057 |
Fires may be severe during prolonged drought in the swamps in which
overcup oak occurs. Fires in these bottomlands are usually surface
fires which destroy young seedlings and saplings of all species, and
scorch the bark of larger trees, including overcup oaks [35].
Rounded Global Status Rank: G5 - Secure
| License | http://creativecommons.org/licenses/by-nc/3.0/ |
| Rights holder/Author | NatureServe |
| Source | http://explorer.natureserve.org/servlet/NatureServe?searchName=Quercus+lyrata |