Angiosperms (Flowering Plants) • Earth.com

Fraxinus angustifolia

(Fraxinus angustifolia)

galery
en

Description

Fraxinus angustifolia, the narrow-leaved ash, is a species of Fraxinus native to central and southern Europe, northwest Africa, and southwest Asia. It is a medium-sized deciduous tree growing to 20–30 m tall with a trunk up to 1.5 m diameter. The bark is smooth and pale grey on young trees, becoming square-cracked and knobbly on old trees. The buds are pale brown, which readily distinguishes it from the related Fraxinus excelsior (black buds) even in winter. The leaves are in opposite pairs or whorls of three, pinnate, 15–25 cm long, with 3–13 leaflets; the leaflets being distinctively slender, 3–8 cm long and 1–1.5 cm broad. The flowers are produced in inflorescences which can be male, hermaphrodite or mixed male and hermaphrodite. The male and hermaphrodite flowers occur on all individuals, i.e. all trees are functionally hermaphrodite. Flowering occurs in early spring. The fruit when fully formed is a samara 3–4 cm long, the seed 1.5–2 cm long with a pale brown wing 1.5–2 cm long. Fraxinus angustifolia subsp. angustifolia has become a weed in many parts of Australia, where it is known as Desert Ash. It has been widely planted as a street and park tree, and has spread to native bushland and grasslands, as well as stream banks and drainage lines, out-competing native plants for moisture, light and nutrients. Fraxinus commonly called ash, is a genus of flowering plants in the olive and lilac family, Oleaceae. It contains 45–65 species of usually medium to large trees, mostly deciduous, though a number of subtropical species are evergreen. The genus is widespread across much of Europe, Asia, and North America. The leaves are opposite (rarely in whorls of three), and mostly pinnately compound, though simple in a few species. The seeds, popularly known as "keys" or "helicopter seeds", are a type of fruit known as a samara. Some Fraxinus species are dioecious, having male and female flowers on separate plants but sex in ash is expressed as a continuum between male and female individuals, dominated by unisexual trees. With age, ash may change their sexual function from predominantly male and hermaphrodite towards femaleness; if grown as an ornamental and both sexes are present, ashes can cause a considerable litter problem with their seeds. Rowans or mountain ashes have leaves and buds superficially similar to those of true ashes, but belong to the unrelated genus Sorbus in the rose family.

Taxonomic tree:

Domain:
Kingdom: Plantae
Phylum:
Class: Magnoliopsida
Order:Lamiales
Family:Oleaceae
Genus:Fraxinus
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