A small tree free from down in all parts, forming a rounded, dense head of branches; young shoots with small white warts. Leaves often in threes, 9 to 12 in. long; leaflets usually nine or eleven, sometimes seven, scarcely stalked, ovate-lanceolate, 2 to 31⁄2 in. long, 3⁄4 to 1 in. wide, obliquely tapered at the base, long-pointed, rather coarsely triangular-toothed; the terminal one is up to 5 in. long and 11⁄2 in. wide, the others decreasing in size successively towards the base. The main-stalk has a continuous groove on the upper side, which, with the large terminal leaflet, distinguishes this from the other ashes with perfectly glabrous shoots and leaves. Fruits 1 in. long, 1⁄3 in. wide, pointed.
This ash was named F. obliqua by Tausch in 1834 at which time it was in cultivation as F. rotundifolia, a name which clung to it for over seventy years. According to Lingelsheim, a monographer of the ashes, it is a native of the eastern Mediterranean region and W. Asia, but a curious uncertainty as to its origin has always prevailed. Tausch thought it came from North America.
Note. The ash described above, which is still in the Kew collection, was received under the name F. rotundifolia. It agrees with F. willdenowiana Koehne, under which name it is treated in Elwes and Henry, Tr. Gt. Brit. & Irel., Vol. 4, p. 884. Its identification with the F. obliqua of Tausch rests on the authority of Lingelsheim. There is also in the Kew collection an ash received under the name F. excelsior var. obliqua, which is quite distinct from the tree described above and appears to be a variant of F. excelsior.