Quercus havardii |
Quercus alba |
|
---|---|---|
Havard oak, Havard's oak, Havard's shinnery oak, sand shinnery oak, sand shinoak, shinnery oak |
chêne blanc, eastern white oak, white oak |
|
Habit | Shrubs, deciduous, low, forming clones 0.3-1.5 × 10 m, rhizomatous. | Trees, deciduous, to 25 m. Bark light gray, scaly. |
Bark | light gray, scaly-papery. |
|
Twigs | brown or grayish, 1-2.5 mm diam., glabrous or densely short grayish or yellowish tomentulose, glabrate in age. |
green or reddish, becoming gray, 2-3(-4) mm diam., initially pubescent, soon glabrous. |
Buds | dark red-brown, subglobose, ca. 2 mm, sparsely pubescent. |
dark reddish brown, ovoid, ca. 3 mm, apex obtuse, glabrous. |
Leaves | blade green, often turning brownish with age, polymorphic, oblong or elliptic or sometimes lanceolate to oblanceolate or ovate to obovate, (30-)50-100 × (10-)20-50 mm, rather thick and hard, base rounded to cuneate, margins flat to revolute, at least some undulate, 2-3 rounded teeth on each side, secondary veins 5-8 on each side, much branched, apex broadly rounded, rarely acute; surfaces abaxially densely grayish or yellowish tomentulose or stellate-pubescent, sometimes only sparsely pubescent, secondary veins quite prominent, adaxially lustrous, very sparsely stellate-pubescent or glabrate, secondary veins very slightly if at all raised. |
blade obovate to narrowly elliptic or narrowly obovate, (79-)120-180(-230) × (40-)70-110(-165) mm, base narrowly cuneate to acute, margins moderately to deeply lobed, lobes often narrow, rounded distally, sinuses extending 1/3-7/8 distance to midrib, secondary veins arched, divergent, (3-)5-7 on each side, apex broadly rounded or ovate; surfaces abaxially light green, with numerous whitish or reddish erect hairs, these quickly shed as leaf expands, adaxially light gray-green, dull or glossy. |
Acorns | solitary or paired, subsessile or on peduncle to 10(-18) mm; cup from deeply cup-shaped to goblet-shaped, 10-12 mm deep × 15-25 mm wide, enclosing 1/3-1/2 nut, base rounded or slightly constricted, margin very thin and smooth, scales reddish brown, triangular-ovate to long-acute, proximally moderately to markedly tuberculate, pubescent, often canescent, tips loosely appressed; nut brown, ovoid, 12-25 × 14-18 mm. |
1-3, subsessile or on peduncle to 25(-50) mm; cup hemispheric, enclosing 1/4 nut, scales closely appressed, finely grayish tomentose; nut light brown, ovoid-ellipsoid or oblong, (12-)15-21(-25) × 9-18 mm, glabrous. |
Cotyledons | distinct. |
distinct. |
2n | = 24. |
|
Quercus havardii |
Quercus alba |
|
Phenology | Flowering spring. | Flowering in spring. |
Habitat | Deep, shifting or stabilized sand dunes, off deep sands in putative hybrid populations | Moist to fairly dry, deciduous forests usually on deeper, well-drained loams, also on thin soils on dry upland slopes, sometimes on barrens |
Elevation | 500-1500 m (1600-4900 ft) | 0-1600 m (0-5200 ft) |
Distribution |
NM; OK; TX
|
AL; AR; CT; DE; FL; GA; IL; IN; KS; KY; LA; MA; MD; ME; MI; MN; MO; MS; NC; NE; NH; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; VT; WI; WV; ON; QC
|
Discussion | Individual clones emerging to heights of 2-3 m from thickets occur sporadically across the Texas range of Quercus havardii and express some characteristics of Q. stellata, such as more deeply lobed leaves and smaller acorns. Such putative hybrids increase in frequency in the eastern part of the range of the species. Material of Quercus havardii from the Navajo Basin of Utah and adjacent Arizona has been treated as Q. havardii var. tuckeri Welsh. Welsh followed J. M. Tucker (1970) and interpreted these intermediate populations as putative hybrids between Q. havardii and both Q. turbinella and Q. gambelii. Giving varietal rank, instead of nothospecies status, to such populations seems arbitrary, and it certainly is inconsistent with their putative hybrid origins. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Considerable variation in depth of lobing occurs in the leaves of Quercus alba (M. J. Baranski 1975; J. W. Hardin 1975); the species is easily distinguished from others, however, by the light gray-green, glabrous mature leaves and cuneate leaf bases. In the past Quercus alba was considered to be the source of the finest and most durable oak lumber in America for furniture and shipbuilding. Now it has been replaced almost entirely in commerce by various species of eastern red oak (e.g., Q. rubra, Q. velutina, and Q. falcata) that are more common and have faster growth and greater yields. These red oaks also lack tyloses and therefore are more suited to pressure treating with preservatives, even though they are less decay-resistant without treatment. Medicinally, Quercus alba was used by Native Americans to treat diarrhea, indigestion, chronic dysentery, mouth sores, chapped skin, asthma, milky urine, rheumatism, coughs, sore throat, consumption, bleeding piles, and muscle aches, as an antiseptic, and emetic, and a wash for chills and fevers, to bring up phlegm, as a witchcraft medicine, and as a psychological aid (D. E. Moerman 1986). Numerous hybrids between Quercus alba and other species of white oak have been reported, and some have been named. J. W. Hardin (1975) reviewed the hybrids of Quercus alba. Nothospecies names based on putative hybrids involving Q. alba include: Q. ×beadlei Trelease (= Q. alba × prinus), Q. ×bebbiana Schneider (= Q. alba × macrocarpa), Q. ×bimundorum E. J. Palmer (= Q. alba × robur), Q. ×deami Trelease (= Q. alba × muhlenbergii), Q. ×faxoni Trelease (= Q. alba × prinoides), Q. ×jackiana Schneider (= Q. alba × bicolor), and Q. ×saulei Schneider (= Q. alba × montana). (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 | ||
Name authority | Rydberg: Bull. New York Bot. Gard. 2: 213. (1901) | Linnaeus: Sp. Pl. 2: 996. (1753) |
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