Quercus stellata |
Quercus margarettae |
|
---|---|---|
post oak |
dwarf post oak, runner oak, sand post oak |
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Habit | Trees, deciduous, to 20(-30) m. Bark light gray, scaly. | |
Bark | light gray, scaly. |
|
Twigs | yellowish or grayish, (2-)3-5 mm diam., densely stellate-pubescent. |
green or reddish, becoming gray, 1-2(-3) mm diam., glabrous. |
Buds | reddish brown, ovoid, to 4 mm, apex obtuse or acute, sparsely pubescent. |
reddish brown, ovoid, 2-3(-6) mm, apex obtuse, sparsely pubescent to glabrate. |
Leaves | blade obovate to narrowly obovate, elliptic or obtriangular, 40-150(-200) × 20-100(-120) mm, rather stiff and hard, base rounded-attenuate to cordate, sometimes cuneate, margins shallowly to deeply lobed, lobes rounded or spatulate, usually distal 2 lobes divergent at right angles to midrib in cruciform pattern, secondary veins 3-5 on each side, apex broadly rounded; surfaces abaxially yellowish green, with crowded yellowish glandular hairs and scattered minute, 6-8-rayed, appressed or semi-appressed stellate hairs, not velvety to touch, adaxially dark or yellowish green, dull or glossy, sparsely stellate, often somewhat sandpapery with harsh hairs. |
blade obovate to narrowly obovate, (25-)40-80(-135) × 20-40(-80) mm, base cuneate to rounded-attenuate, margins moderately to deeply lobed, lobes rounded or spatulate, sometimes middle or distal 2 lobes compound, with secondary lobe on proximal side, divergent at right angles, forming cruciform pattern, secondary veins 3-5 on each side, apex broadly rounded; surfaces abaxially light green, with interlocking, erect, 2-4(-6)-rayed stellate hairs, velvety to touch, adaxially dark green, glossy, glabrous or sparsely stellate, not harsh to touch. |
Acorns | 1-3, subsessile or on peduncle to 6(-40) mm; cup deeply saucer-shaped, proximally rounded or constricted, 7-12(-18) mm deep × (7-)10-15(-25) mm wide, enclosing 1/4-2/3 nut, scales tightly appressed, finely grayish pubescent; nut light brown, ovoid or globose, 10-20 × 8-12(-20) mm, glabrous or finely puberulent. |
1-3, subsessile or on peduncle to 20 mm; cup deeply cup-shaped, basally rounded or constricted, (7-)9-12 mm deep × 12-20 mm wide, enclosing to 3/4 nut, scales loosely appressed, finely grayish pubescent; nut light brown, ovoid, 15-25(-30) × 9-13(-16) mm, glabrous. |
Cotyledons | distinct. |
distinct. |
Small | trees or shrubs , deciduous, to 12 m, sometimes rhizomatous. |
|
Quercus stellata |
Quercus margarettae |
|
Phenology | Flowering spring. | |
Habitat | Usually on xeric sites, dry gravelly and sandy ridges and uplands, dry clays, prairies and limestone hills, woodlands and deciduous forests | Deep sands and gravels, often in dense woods as understory or in open scrubland and pine barrens |
Elevation | 0-750 m (0-2500 ft) | 0-600 m (0-2000 ft) |
Distribution |
AL; AR; CT; DE; FL; GA; IA; IL; IN; KS; KY; LA; MA; MD; MO; MS; NC; NJ; NY; OH; OK; PA; RI; SC; TN; TX; VA; WV
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AL; AR; FL; GA; LA; MO; MS; NC; OK; SC; TX; VA
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Discussion | Quercus stellata is often identified by its commonly cross-shaped leaf form, particularly in the eastern part of its range. All individuals and populations do not express this characteristic, however. Moreover, Q. stellata has broad overlap with Q. margaretta and even with some forms of the blackjack oak, Q. marilandica, one of its most common associates. The thick yellowish twigs with indument of stellate hairs and the dense harsh stellate hairs on the abaxial leaf surface are better diagnostic characteristics when variation includes leaf forms that are not obviously cruciform. Native Americans used Quercus stellata medicinally for indigestion, chronic dysentery, mouth sores, chapped skin, hoarseness, and milky urine, as an antiseptic, and as a wash for fever and chills (D. E. Moerman 1986). Putative hybrids are known with Quercus marilandica, Q. alba, and various other white oaks. Quercus stellata is also one of the few oaks that appears to produce hybrids with species in the live oak group, although obvious intermediates are rarely encountered. Nothospecies names based on putative hybrids involving Q. stellata include: Q. ×stelloides E. J. Palmer (= Q. prinoides × Q. stellata), Q. ×mahloni E. J. Palmer (as Q. sinuata var. breviloba × Q. stellata), Q. ×pseudomargaretta Trelease (= Q. margaretta × Q. stellata), Q. ×sterretti Trelease (= Q. lyrata × Q. stellata), Q. ×macnabiana Sudworth (= Q. sinuata × Q. stellata), Q. ×guadalupensis Sargent (= Q. sinuata × Q. stellata), Q. ×fernowi Trelease (= Q. alba × Q. stellata), and Q. ×bernardensis W. Wolf (= Q. montana × Q. stellata). (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Historical records for Quercus margaretta exist for New York, but no current population is known there. Populations of post oak in east Texas (the Cross Timbers region) on sands and gravels exhibit characteristics somewhat intermediate between Quercus stellata and Q. margaretta; most of the trees at those localities have leaves with abaxial surface similar to Q. margaretta, leaf shape more similar to Q. stellata, and twigs somewhat intermediate between the two species in diameter and varying from tightly pubescent to glabrate. Acorn characters tend toward Q. margaretta as well. These populations have been treated as Q. drummondii Liebmann, the Drummond post oak. Similar intermediates occur sporadically throughout the range of the post oaks in southeastern United States, but they do not form such continuous and morphologically stable populations; perhaps the Texas material is best treated as a nothospecies, Q. ×drummondii. (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. minor, Q. obtusiloba | Q. minor var. margaretta, Q. stellata var. margaretta |
Name authority | Wangenheim: Beytr. Teut. Forstwiss., 78, plate 6, fig. 15. (1787) | (Ashe) J. K. Small: in J. K. Small, Fl. S.E. U.S., 355. (1903) |
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