Quercus hemisphaerica (sand laurel oak, laurel oak, Darlington oak, laurel-leaf oak) is a species of oak native to the southeastern and south-central United States. It is in the red oak section of Quercus sect. Lobatae. It is often confused with and closely related to Quercus laurifolia (swamp laurel oak), from which it differs in several key characteristics.
| Quercus hemisphaerica | |
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Scientific classification 
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| Kingdom: | Plantae |
| Clade: | Tracheophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Rosids |
| Order: | Fagales |
| Family: | Fagaceae |
| Genus: | Quercus |
| Subgenus: | Quercus subg. Quercus |
| Section: | Quercus sect. Lobatae |
| Species: | Q. hemisphaerica
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| Binomial name | |
| Quercus hemisphaerica | |
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| Synonyms[2] | |
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List
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Description
editQuercus hemisphaerica is a medium-sized evergreen to semi-evergreen tree which can grow as tall as 35 meters (115 feet) with a trunk diameter of 1.5 m (5 ft), although it is more commonly around 18–20 m (59–66 ft) tall. The leaves are entire, without teeth except one apical awn (rarely with a few teeth near the apex), mostly elliptical or narrowly ovate, and 3–12 centimeters (1+1⁄8–4+3⁄4 inches) long by 1–4 cm (3⁄8–1+5⁄8 in) wide. The petiole is very short, ranging from 1–5 millimeters (1⁄16–3⁄16 in) long, and the leaf base is obtuse to rounded. The acorns are hemispheric in shape and 9 to 16.5 mm (3⁄8 to 5⁄8 in) by 9 to 16.5 mm (3⁄8 to 5⁄8 in). The acorns take 18 months to mature and are a fourth to a third covered by a saucer- to bowl-shaped cap.[3]
Similar species
editQ. hemisphaerica resembles Quercus laurifolia (swamp laurel oak). They can be distinguished using these criteria.
- When both sand laurel oak and swamp laurel oak are growing in the same area, sand laurel oak will flower about two weeks later than swamp laurel oak.
- Sand laurel oak grows on dry sandy soils, while swamp laurel oak grows on flood plains, river bottoms, and occasionally poorly drained upland soils.
- Sand laurel oak has narrow ovate or elliptic leaves, while swamp laurel oak has rhombic or broad ovate leaves.
- Sand laurel oak has an acute leaf apex and a rounded or obtuse (blunt, >90°) leaf base, while swamp laurel oak has an obtuse or rounded leaf apex and a cuneate or attenuate leaf base.
- Sand laurel oak is mostly evergreen, while swamp laurel oak is mostly tardily deciduous.
Distribution and habitat
editThe tree can be found from Texas to Delaware.[4]
It grows in somewhat xeric sandy soils, on sand hills, and sometimes on hillsides.
Ecology
editThere is at least one known hybrid involving Q. hemisphaerica which is with Q. laevis (Q. × mellichampii Trel.).
References
edit- ^ Wenzell, K.; Kenny, L. (2015). "Quercus hemisphaerica". IUCN Red List of Threatened Species. 2015: e.T194137A2302375. doi:10.2305/IUCN.UK.2015-4.RLTS.T194137A2302375.en. Retrieved 12 November 2021.
- ^ The Plant List, Quercus hemisphaerica Bartram ex Willd.
- ^ Flora of North America: Laurel Oak
- ^ Biota of North America Program 2014 county distribution map
External links
edit- North Carolina State Fact Sheet: Laurel Oak
- Auburn University, Trees of Alabama and the Southeast: Laurel Oak
- Virginia Tech, Department of Forestry Fact Sheet: Darlington oak
- United States Department of Agriculture plants profile: Darlington oak
- Floridata: Quercus hemisphaerica
- Institute of Food and Agricultural Sciences, University of Florida: Laurel Oak or Swamp Laurel Oak?