Ohio horse chestnut
| Ohio horse chestnut | ||||||||||||
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Ohio horse chestnut ( Aesculus glabra ) |
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| Aesculus glabra | ||||||||||||
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The Ohio horse chestnut ( Aesculus glabra ) is a native of North America representative of the horse chestnut ( Aesculus ). It occurs in two varieties , which differ mainly in their leaves and whose areas of distribution only overlap in a narrow area.
Variety glabra
features
The nominate variety Aesculus glabra var. Glabra consists of trees or shrubs that reach heights of 10 to 30 m and a trunk diameter of 40 cm, rarely up to 80 cm. The bark of young trees is light to dark gray-brown and becomes smooth and ash-gray to almost white with age; it is often light or dark gray-brown and divided into small, thin plates by shallow cracks. The twigs are reddish-brown, later light gray, glabrous and give off a slightly smelly odor when injured. The buds are conical and pointed to pointed. The outer bud scales are keeled and have a lashed edge.
The leaves are palmate and consist of 5 to 7 leaflets. The petiole is 5 to 15 cm long. The leaflets are 6 to 16 cm long and 2 to 6 cm wide; their shape is oblong-egg-shaped to elliptical-egg-shaped. The end of the leaflet is pointed or pointed, the leaf margin unevenly serrated, often with entire margins at the base. The underside of the leaf is bare, scattered with hair on the nerves, until densely and woolly hairy, dark green, pale or blue-green. The leaflet stalks are up to 11 mm long.
The inflorescence is 10 to 15 cm long, glabrous or densely hairy. The flowers are pale yellow or greenish yellow. The flower stalk is 2 to 5 mm long. The calyx is bell-shaped, 3 to 8 mm long, hairy, the five calyx lobes are rounded, blunt and unequal. The crown consists of four almost identical petals that are 10 to 19 mm long. The upper petals have a shaggy hairy nail that is half the length of the plate and the same length as the calyx. The plate is oblong-spatulate and narrower than the plate of the laterally standing petals. It has shaggy hair and no glands. The lateral petals have a short, shaggy nail and a wide, oval to elongated plate. The seven stamens are 15 to 23 mm long. The stamens are curved and shaggy in the lower half. The anthers are orange, slightly hairy at the tip and base, and finely glandular at the tip and base of the loculi. The pistil is glandular-shaggy on the ovary and shaggy on the style.
The capsule fruit is ovoid to obovate and has a diameter of 2 to 5 cm. The pericarp is bumpy to prickly, the spines often fall off, sometimes missing from the beginning. The fruit is light brown. There are 1 to 3 seeds per fruit, rarely 4 to 6, they have a diameter of 2 to 4 cm, are dark brown with a small, light navel .
Distribution and ecology
The glabra variety is widespread. The area extends from western Pennsylvania to the west into the Appalachian Mountains and the lowlands of Iowa , to the south into the highlands of western Arkansas ; the Nashville , central Tennessee, and northern Alabama basins . There are isolated occurrences in central Alabama, eastern central Mississippi, and eastern Tennessee. It grows on fertile alluvial land of rivers or on fertile sandstone or limestone soil in hill country. The shrub shape often forms thickets along river banks. It occurs more often as a small, scattered tree.
Variety arguta
features
The arguta variety is a shrub or small tree, grows up to 6 m high and reaches a trunk diameter of up to 15 cm. The foliage leaf consists of 7 to 11 leaflets, more than in the nominate form. The leaflets are 5 to 16 cm long and 1 to 3 (rarely 5) cm narrower than in the nominate form. The leaf margin is often double serrated.
Distribution and ecology
The variety arguta comes from the hill country m northeast of Kansas south along the western edge of the Interior Highlands to the Sandy Hills of east-central Texas . From here to the southwest to Real County . It is very common as an undergrowth shrub on slopes and embankments, and on the steep banks of rivers and streams.
Chromosome number
The number of chromosomes is 2n = 40.
variability
There is a great deal of variability within the species. Much of this is due to introgression of Aesculus pavia and Aesculus flava . There are also different ecotypes. Many of these variants have been described as separate taxa, but they are no longer considered valid.
There is a clear east-west gradient for two characteristics: the relative width of the leaflets decreases from east to west, while the number of leaflets increases. In essence, the slope is gradual, with a steep slope in the area where the two varieties overlap. The overlap is a narrow zone in west Missouri and west Arkansas, the individuals occurring here are often difficult to assign to one of the two varieties.
use
Besides Aesculus flava, the Ohio horse chestnut is the only species of the genus in America that is used for forestry purposes. The wood is processed into furniture, floors, boxes and musical instruments.
supporting documents
- James W. Hardin: A Revision of the American Hippocastanaceae II . Brittonia, Volume 9, 1957, pp. 173-195.
Individual evidence
- ↑ Aesculus glabra var. Arguta at Tropicos.org. In: IPCN Chromosome Reports . Missouri Botanical Garden, St. Louis
- ↑ Schütt, Schuck, Stimm: Lexicon of tree and shrub species . Nikol, Hamburg 2002, p. 30. ISBN 3-933203-53-8
Web links
- Distribution map (United States Geological Survey; PDF file; 686 kB)