Quercus fusiformis |
Quercus laceyi |
|
---|---|---|
escarpment live oak, live oak, plateau oak, Texas live oak |
lacey oak |
|
Habit | Trees, sometimes shrubs, subevergreen, trees to 25 m, shrubs often forming large clonal stands. | Trees, deciduous, to 5-8(-10) m. Bark light colored, papery or scaly. |
Bark | dark brown or black, scaly. |
|
Twigs | light gray, 1.5-3 mm diam., tomentulose, tomentulum often persistent in age. |
gray, 1.5-2 mm diam., pubescent with erect stellate hairs, these soon shed, at maturity reddish and pruinose to tan and glabrous. |
Buds | reddish or dark brown, subglobose or ovate, 1.5-3 mm; scale margins glabrous or puberulent. |
brown, ovoid to ovoid-lanceoloid, 1.5-3 × 1-2 mm, apex acute, glabrous. |
Leaves | blade oblong-elliptic to narrowly ovate or lanceolate, sometimes obovate, ± planar, (10-)35-90(-150) × (15-)20-40(-85) mm, base rounded to truncate or cordate, rarely cuneate, margins minutely revolute or flat, entire or irregularly 1-3 toothed on each side, teeth mucronate (rarely spinose in suckers or juveniles), secondary veins obscure, 8-10 on each side, apex obtuse-rounded or acute; surfaces abaxially whitish or glaucous, densely covered with minute, appressed, fused-stellate hairs, light green and glabrate in shade leaves, adaxially dark or light green, glossy, glabrous or with minute, scattered, stellate hairs. |
blade blue-green, glaucous, obovate or elliptic, (20-)40-90(-210) × (20-)30-60(-110) mm, thin, base cuneate and decurrent on petiole to rounded or rarely somewhat cordate, margins thin, flat, entire to shallowly lobed or (rarely in shade forms) deeply lobed, lobes if present oblong, squarish, often retuse, secondary veins 6-9 on each side, each terminating in tooth or arching near margins, apex broadly rounded, retuse; surfaces abaxially whitish, with erect stellate hairs, hairs shed as leaves expand, becoming glabrous, glaucous, adaxially glabrous, glaucous. |
Acorns | 1-3, on peduncle 3-30 mm; cup funnel-shaped, hemispheric, or deeply goblet-shaped, 8-15 mm deep × 6-12(-15) mm wide, base often constricted, scales whitish or grayish, thickened basally, keeled, acute-attenuate, tomentulose, tips reddish, glabrous or puberulent; nut dark brown, often with light brown longitudinal stripes, subfusiform and acute to narrowly barrel-shaped, rarely distally rounded, (17-)20-30(-33) × 8-15 mm, glabrous. |
annual, solitary or paired, subsessile or on short peduncle to 10(-20) mm in leaf axil; cup saucer-shaped or shallowly cup-shaped, 4-7 mm deep × 10-12(-18) mm wide, enclosing 1/3 nut or less, scales moderately tuberculate, finely tomentose; nut oblong or barrel-shaped, often flattened at both ends, (11-)13-15(-20) × 9-11(-14) mm. |
Cotyledons | connate. |
distinct. |
Quercus fusiformis |
Quercus laceyi |
|
Phenology | Flowering spring. | Flowering in spring. |
Habitat | Hills, grasslands, scrublands, open woodlands, oak-juniper woodland, and margins of thorn scrub, often on limestone or deep calcareous loams, sometimes on granular sand or gravel | Limestone hills, woodlands and riparian forests, canyons and streamsides |
Elevation | 0-1200 m (0-3900 ft) | 350-2200 m (1100-7200 ft) |
Distribution |
OK; TX; Mexico (Coahuila, Nuevo León, and Tamaulipas)
|
TX; Mexico (Coahuila and Nuevo León) |
Discussion | The difficulty in distinguishing Texas populations of Quercus fusiformis from Q. virginiana is reflected in a variety of taxonomic treatments, including reducing Q. fusiformis to varietal rank under Q. virginiana. The latter disposition is problematic, however, because Q. fusiformis in northeastern Mexico is amply distinct from Q. virginiana and appears to be more closely related to Q. brandegei Goldmann, an endemic of Baja California, Mexico. Thus, here we assume that the intergradation of Q. virginiana and Q. fusiformis is a result of secondary contact, and is not primary clinal variation. Under this interpretation, Q. virginiana in typical form extends into Texas only as far west as the Brazos River drainage along the coast from there to the escarpment of the Edwards Plateau; most populations elsewhere are either intermediate between the two species or show greater affinity with Q. fusiformis. On the Edwards Plateau, the live oak populations are small trees forming rhizomatous copses (shinneries) and having mostly acute acorns. Populations of live oak on deep sands in south Texas differ from typical Quercus fusiformis in having broader, more rounded leaves, often with the secondary veins somewhat impressed abaxially, and relatively blunt, barrel-shaped acorns. These characteristics suggest introgresion from the Mexican-Central American species Q. oleoides Schlechtendal & Chamisso, which in its typical form reaches north only as far as southern Tamaulipas, Mexico. The name Q. oleoides var. quaterna C. H. Muller has been applied to what is apparently a shrub form of one of these Q. fusiformis × Q. oleoides hybrids. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Material from Texas and northeastern Mexico, excluding the type, has been incorrectly referred to Quercus glaucoides M. Martens & Galeotti by some authors (K. C. Nixon and C. H. Muller 1992). On the Edwards Plateau of Texas, Quercus laceyi occurs mostly at 350-600 m elevation; in Coahuila and Nuevo León, it occurs at 1500-2200 m. This species is sometimes associated with remnant mesic forests, which include Acer grandidentatum Nuttall, Tilia species, Quercus muhlenbergii Engelmann, and various pine and other oak species. The leaves are shallowly lobed or entire, although occasional specimens on moist sites are deeply lobed and resemble the leaves of Q. alba in outline. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 3. | FNA vol. 3. |
Parent taxa | Fagaceae > Quercus > sect. Quercus | Fagaceae > Quercus > sect. Quercus |
Sibling taxa | ||
Synonyms | Q. virginiana var. fusiformis | Q. breviloba subsp. laceyi |
Name authority | Small: Bull. Torrey Bot. Club 28: 357. (1901) | Small: Bull. Torrey Bot. Club 28: 358. (1901) |
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