''Oxydendrum arboreum'', the sourwood or sorrel tree, is the sole
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
in the
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
''Oxydendrum'', in the family
Ericaceae
The Ericaceae () are a Family (biology), family of flowering plants, commonly known as the heath or heather family, found most commonly in acidic and infertile growing conditions. The family is large, with about 4,250 known species spread acros ...
. It is native to eastern
North America
North America is a continent in the Northern Hemisphere, Northern and Western Hemisphere, Western hemispheres. North America is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South Ameri ...
, from southern
Pennsylvania
Pennsylvania, officially the Commonwealth of Pennsylvania, is a U.S. state, state spanning the Mid-Atlantic (United States), Mid-Atlantic, Northeastern United States, Northeastern, Appalachian, and Great Lakes region, Great Lakes regions o ...
south to northwest
Florida
Florida ( ; ) is a U.S. state, state in the Southeastern United States, Southeastern region of the United States. It borders the Gulf of Mexico to the west, Alabama to the northwest, Georgia (U.S. state), Georgia to the north, the Atlantic ...
and west to southern
Illinois
Illinois ( ) is a U.S. state, state in the Midwestern United States, Midwestern United States. It borders on Lake Michigan to its northeast, the Mississippi River to its west, and the Wabash River, Wabash and Ohio River, Ohio rivers to its ...
; it is most common in the lower chain of the
Appalachian Mountains
The Appalachian Mountains, often called the Appalachians, are a mountain range in eastern to northeastern North America. The term "Appalachian" refers to several different regions associated with the mountain range, and its surrounding terrain ...
. The tree is frequently seen as a component of
oak-heath forests.
Growth
Sourwood is a small
tree
In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, e.g., including only woody plants with secondary growth, only ...
or large
shrub
A shrub or bush is a small to medium-sized perennial woody plant. Unlike herbaceous plants, shrubs have persistent woody stems above the ground. Shrubs can be either deciduous or evergreen. They are distinguished from trees by their multiple ...
, growing to tall with a trunk up to diameter. Occasionally on extremely productive sites, this species can reach heights in excess of 30 meters and 60 cm diameter. The
leaves
A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...
are alternately arranged,
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 Leaf, leaves, usually in the autumn; to the shedding of petals, aft ...
, long and broad, with a finely
serrated margin; they are dark green in summer, but turn vivid red in fall. The
flower
Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...
s are white, bell-shaped, 6–9 mm ( 1/4 to 1/3 inch) long, produced on long
panicle
In botany, a panicle is a much-branched inflorescence. (softcover ). Some authors distinguish it from a compound spike inflorescence, by requiring that the flowers (and fruit) be pedicellate (having a single stem per flower). The branches of a p ...
s. The
fruit
In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering.
Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...
is a small woody
capsule. The
root
In vascular plants, the roots are the plant organ, organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often bel ...
s are shallow, and the tree grows best when there is little root competition; it also requires
acidic soil
Soil pH is a measure of the acidity or basicity (alkalinity) of a soil. Soil pH is a key characteristic that can be used to make informative analysis both qualitative and quantitatively regarding soil characteristics. pH is defined as the nega ...
s for successful growth. The leaves can be chewed (but should not be swallowed) to help alleviate a dry-feeling mouth.
Description

The bark is gray with a reddish tinge, deeply furrowed and scaly. Branchlets at first are light yellow green, but later turn reddish brown. The wood is reddish brown, with paler
sapwood; it is heavy, hard, and close-grained, and will take a high polish. Its specific gravity is 0.7458, with a density of 46.48 lb/cu ft.
The winter buds are
axillary, minute, dark red, and partly immersed in the bark. Inner scales enlarge when spring growth begins.
Leaves are
alternate
Alternative or alternate may refer to:
Arts, entertainment and media
* Alternative (''Kamen Rider''), a character in the Japanese TV series ''Kamen Rider Ryuki''
* Alternative comics, or independent comics are an alternative to mainstream superh ...
, four to seven inches long, 1.5 to 2.5 inches wide, oblong to
oblanceolate, wedge-shaped at the base, serrate, and acute or
acuminate
The following terms are used to describe leaf plant morphology, morphology in the description and taxonomy (biology), taxonomy of plants. Leaves may be simple (that is, the leaf blade or 'lamina' is undivided) or compound (that is, the leaf blade ...
. Leaf veins are
feather-veined, the
midrib
A primary vein, also known as the midrib, is the main vascular structure running through the center of a leaf. The primary vein is crucial for the leaf’s efficiency in photosynthesis and overall health, as it ensures the proper flow of material ...
is conspicuous. They emerge from the bud
revolute, bronze green and shining, and smooth; when full-grown, they are dark green, shining above, and pale and glaucous below. In autumn, they turn bright scarlet.
Petioles are long and slender, with
stipule
In botany, a stipule is an outgrowth typically borne on both sides (sometimes on just one side) of the base of a leafstalk (the petiole (botany), petiole). They are primarily found among dicots and rare among monocots. Stipules are considered part ...
s wanting. They are heavily laden with acid.
In June and July, cream-white flowers are borne in terminal panicles of secund
raceme
A raceme () or racemoid is an unbranched, indeterminate growth, indeterminate type of inflorescence bearing flowers having short floral stalks along the shoots that bear the flowers. The oldest flowers grow close to the base and new flowers are ...
s seven to eight inches long; rachis and short pedicels are downy. The
calyx is five-parted and persistent;
lobes are
valvate in bud. The
corolla is ovoid-cylindric, narrowed at the throat, cream-white, and five-toothed. The 10
stamen
The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10
Morphology and terminology
A stamen typically consists of a stalk called the filament ...
s are inserted on the corolla; filaments are wider than the
anther
The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10
Morphology and terminology
A stamen typically consists of a stalk called the filament ...
s; anthers are two-celled. The
pistil
Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl (botany), whorl of a flower; it consists ...
is ovary superior, ovoid, and five-celled; the style is columnar; the stigma is simple; the disk is ten-toothed, and ovules are many.
The fruit is a
capsule, downy, five-valved, five-angled, and tipped by the persistent style; the
pedicels
In botany, a pedicel is a stem that attaches a single flower to the inflorescence
In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branch ...
are curving.
Cultivation and uses
The sourwood is hardy in the north and a worthy
ornamental tree
Ornamental plants or ''garden plants'' are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars th ...
in lawns and parks. Its late bloom makes it desirable, and its autumnal coloring is particularly beautiful and brilliant. The leaves are heavily charged with acid, and to some extent have the poise of those of the
peach
The peach (''Prunus persica'') is a deciduous tree first domesticated and Agriculture, cultivated in China. It bears edible juicy fruits with various characteristics, most called peaches and the glossy-skinned, non-fuzzy varieties called necta ...
.
The leaves are also a
laxative
Laxatives, purgatives, or aperients are substances that loosen stools and increase bowel movements. They are used to treat and prevent constipation.
Laxatives vary as to how they work and the side effects they may have. Certain stimulant, lubri ...
.
Sourwood is renowned for the honey that bees produce from the
nectar
Nectar is a viscous, sugar-rich liquid produced by Plant, plants in glands called nectaries, either within the flowers with which it attracts pollination, pollinating animals, or by extrafloral nectaries, which provide a nutrient source to an ...
of its flowers.
Juice from its blooms is used to make sourwood
jelly. The shoots were used by the
Cherokee
The Cherokee (; , or ) people are one of the Indigenous peoples of the Southeastern Woodlands of the United States. Prior to the 18th century, they were concentrated in their homelands, in towns along river valleys of what is now southwestern ...
and the
Catawba to make arrowshafts.
In Appalachian culture
Sourwood Mountain is a popular
old-time tune in the Appalachian region of the United States.
Gallery
Image:Oxydendron arboreum JPG1.jpg, Trunk and leaves
Image:Sourwood in autumn (foliage closeup).JPG, Sourwood in autumn foliage on top of Pilot Mtn., NC. (10-30-2008)
References
External links
''Oxydendrum arboreum'' images at bioimages.vanderbilt.edu''Oxydendrum arboreum images, locations all over the world at PlantNet.org
{{Authority control
Vaccinioideae
Trees of Northern America
Flora of the Appalachian Mountains
Natural history of the Great Smoky Mountains
Medicinal plants of North America
Monotypic Ericaceae genera