Quercus stellata

Systematik

Quercus stellata (post oak, iron oak) is a North American species of oak in the white oak section. It is a slow-growing oak that lives in dry, poor soils, and is resistant to rot, fire, and drought. Interbreeding occurs among white oaks, thus many hybrid species combinations occur.

Introduction

Q. stellata is native to the eastern and central United States, and found in all the coastal states from Massachusetts to Texas, and as far inland as Nebraska. It is identifiable by the rounded cross-like shape formed by the leaf lobes and hairy underside of the leaves.

Description

Post oak is a relatively small tree, typically 10–15 m (33–50 ft) tall and trunk 30–60 cm (1–2 ft) in diameter, though occasional specimens reach 30 m (100 ft) tall and 140 cm (56 in or 4.7 ft) in diameter. The leaves have a very distinctive shape, with three perpendicular terminal lobes, shaped much like a Maltese cross. They are leathery, and tomentose (densely short-hairy) beneath. The branching pattern of this tree often gives it a rugged appearance. The acorns are 1.5–2 cm (0.6-0.8 in) long, and are mature in their first summer.

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Taxonomy

The specific epithet stellata is Latin for "star"; it is named this because the trichome hairs on the bottom of the leaves are stellate or star-shaped. Several variants of Q. stellata were named by American botanist Charles Sprague Sargent. The variety most recognised by the US Forest Service is Q. stellata var. paludosa Sarg (delta post oak)

Varieties

var. margarettiae (Ashe) Sarg.

var. paludosa Sarg.

var. boyntonii (Beadle) Sarg.

var. anomala Sarg.

var. attenuata Sarg.

var. araniosa Sarg.

var. palmeri Sarg.

var. parviloba Sarg.

var. rufescens Sarg.

Hybrids

Hybrid Name	Q. stellata x <sp.>
Q. × stelloides E. J. Palmer	Q . prinoides
Q. × mahloni E. J. Palmer	Q . sinuata var. breviloba
Q. × pseudomargaretta Trelease	Q . margaretta
Q. × sterretti Trelease	Q . lyrata
Q. × macnabiana Sudworth	Q . sinuata
Q. × guadalupensis Sargent	Q . sinuata
Q . × fernowi Trelease	Q . alba
Q. × bernardensis W. Wolf	Q . montana

Similarity to Quercus alba

They are both in a section of Quercus called the white oaks. In the white oak section, Q. stellata is a sister taxon with Quercus alba. Q. stellata is sold and distributed as white oak. One identifiable difference between the two trees is that Q. stellata is 'hairy' on the underside of the leaf.

Distribution and habitat

Q. stellata is found in Southeastern United States, in the coast states from Massachusetts, to Texas, and inland to Iowa. Normally found at the edge of a forest, it typically grows in dry, sandy areas, deficient of nutrients.

Uses

Because of its ability to grow in dry sites, attractive crown, and strong horizontal branches, it is used in urban forestry. It is resistant to decay, so it is used for railroad ties, siding, planks, construction timbers, stair risers and treads, flooring, pulp, veneer, particle board, fuel, and its namesake fence posts. It is used for wildlife food for deer, turkeys, squirrels, and other rodents, but because the nuts contain tannin, it is toxic to cattle.

Fire ecology

Q. stellata has the ability to survive fires by having thicker bark. It is useful for fire surveys where the tree rings are used to get a fire history of an area. A tree ring survey of 36 trees in Illinois provided a 226-year tree ring record that indicated that many Q. stellata persisted through annual fire return intervals of 1.44 fires/year for over 100 years.

External links

• IPNI
• Kew
• Flora of North America
• Plants.USDA.gov
• US Forest Service
• Flora of the Southern and Mid-Atlantic States
• Q. stellata images from Vanderbilt University
• photo of herbarium specimen at Missouri Botanical Garden, collected in Missouri in 1939