Fraxinus angustifolia Vahl
F. excelsior L. subsp. angustifolia (Vahl) Wesm.
Eng.: Narrow-leafed ash. Spa.: Fresno común. Fre.: Frêne à feuilles étroites. Ara.: dardar, rasleut, sella, l-san el asfur. Tam.: tuzzalat, imdes, asel, aslen.
Deciduous tree, polygamous, up to 20(25) m in height, irregular in shape, but ± oval. Trunk straight, thick, promptly branching. Bark highly fissured longitudinal and transversely, reticulated, greyish. Branches erect-patent. Younger branchlets greenish. Buds light brown, chestnut-greenish. Leaves (12-25 cm long) all similar, opposite, imparipinnate with (5)7-13 (15) leaflets (4-8.5 × 1.5-2.5 cm). Leaflets lanceolate, oblong-lanceolate, ovate-lanceolate or elliptical, serrated or entire only at the base, with acute teeth, deep green on both sides, although slightly lighter on the underside. All leaflets are sessile or subsessile, but grouped along a canaliculate and long petiole, glabrous. Inflorescence appears very early, in small lateral opposite racemes. Flowers unisexual —masculine or feminine— or hermaphrodite, very small, reddish, without cup nor corolla, formed only by 2 stamens (1.5-3 mm) and/or a pistil with bilobed stigma. Fruit a samara (2-4.5 cm long), form ovoid-lanceolate to oblong-lanceolate, acute, with a highly compressed seed.
Flowering:
January to March.
Fruiting:
July to September.
Habitat:
It seems indifferent to the type of substrate, but very specific in terms of permanent edaphic moisture, therefore appearing in the deep soils of valley bottoms and more usually along rivers and lakes. From semiarid to humid bioclimate, on thermomediterranean to supramediterranean floors.
Distribution:
Southern Europe and NW Africa. In Africa it is common in rivers and streams in the N, from Morocco to Tunisia. To the S it reaches the High Atlas and the Saharan Atlas, missing from steppic areas. To the E, the Tunisian Dorsal marks its southern boundary.
Observations:
Several subspecies have been described; in North Africa only the type subspecies is found (described above). This tree is of great importance in the fight against erosion. Its roots and strong stems, hold the terrain along rivers and streams, as well as materials that wash away, therefore avoiding soil loss and mitigating the often dramatic effect of floods.
Conservation status:
Relatively common and widespread species. In the IUCN Red List of Threatened Species, it is listed as Least Concern (LC) at global level (Khela, 2013).