''Quercus ellipsoidalis'', the northern pin oak or Hill's oak, is a North American species of

oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

tree native to the north-central

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

and south-central

Canada Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...

, primarily in the

Great Lakes region The Great Lakes region of North America is a binational Canadian–American region that includes portions of the eight U.S. states of Illinois, Indiana, Michigan, Minnesota, New York, Ohio, Pennsylvania and Wisconsin along with the Canadian p ...

and the Upper Mississippi Valley. It most commonly occurs on dry, sandy soils.

Description

''Quercus ellipsoidalis'' is a medium-sized

deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, ...

tree growing to tall with an open, rounded crown. The leaves are glossy green, long and broad, lobed, with five or seven lobes, and deep sinuses between the lobes. Each lobe has 3–7 bristle-tipped teeth. The leaf is nearly hairless, except for small tufts of pale orange-brown down where the lobe veins join the central vein. The acorns tend to be ellipsoid ( ellipse-shaped, from which its scientific name derives), though they tend to be highly variable and range to globose, long and broad, a third to a half covered in a deep cup, green maturing pale brown about 18 months after

pollination Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds, a ...

; the kernel is very bitter. The inner surface of the acorn cap is glabrous (hairless) to sparsely or moderately pubescent, and the hairs if present tend to be kinky rather than straight.

Taxonomy

Although the common name suggests a resemblance to the

pin oak ''Quercus palustris'', the pin oak or swamp Spanish oak, is a tree in the red oak section (''Quercus'' sect. ''Lobatae'') of the genus ''Quercus''. Pin oak is one of the most commonly used landscaping oaks in its native range due to its ease of ...

(''Q. palustris''), ''Q. ellipsoidalis'' has traditionally been thought to be closely related to the

scarlet oak ''Quercus coccinea'', the scarlet oak, is a deciduous tree in the red oak section ''Lobatae'' of the genus ''Quercus'', in the family Fagaceae. It is primarily distributed in the central and eastern United States. It occurs on dry, sandy, usuall ...

(''Q. coccinea''), and was in fact included in that species by many botanists. Recent work suggests that there is more gene flow between Hill's oak and

black oak Black Oak may refer to: Places in the United States * Black Oak, Arkansas * Black Oak, Daviess County, Indiana * Black Oak, Lake County, Indiana, a neighborhood of Gary, Indiana * Black Oak, Missouri Other * Black Oak Arkansas Black Oak Ar ...

(''Q. velutina''), but the phylogenetic position of these species is still uncertain. The morphological similarity between ''Q. ellipsoidalis'' and ''Q. coccinea'' remains a source of confusion, especially in northwestern Indiana and southern Cook County, Illinois.Hipp AL, JA Weber (2008) Systematic Botany 33: 148-158
/ref>

Uses

Northern pin oak is planted as an ornamental tree, popular for its bright red fall color and tolerance of infertile sandy soils. The wood is used for fence posts, fuel and general construction. The cultivar 'Hemelrijk' has gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nor ...

's Award of Garden Merit.

References

External links

* *
Photo of herbarium specimen at Missouri Botanical Garden, collected in Illinois in 1899
{{Taxonbar, from=Q241698 ellipsoidalis Trees of the Great Lakes region (North America) Trees of the Plains-Midwest (United States) Trees of Ontario Plants described in 1899 Least concern plants Least concern flora of North America Least concern flora of the United States