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II. Ornaster, Koehne and Lingelsheim, Mitt. Deut. Dendr. Gesell. 1906, p. 66

Calyx present, persistent under the samara. Corolla absent. Flowers in terminal panicles, appearing with the leaves. Seven species.

III. Sciadanthus, Cosson et Durieu, Bull. Soc. Bot. France, ii. 367 (1855).

Calyx present, persistent under the samara. Corolla absent. Flowers in dense fascicled cymes, axillary on the preceding year’s shoot. Two species.

IV. Leptalix, Rafinesque, New Flora, iii. 93 (1836).

Calyx present, persistent under the samara, panicles, axillary on the preceding year’s shoot. About fifteen species.

V. Fraxinaster, De Candolle, Prod. viii. 276 (in part) (1844).

Calyx and corolla both absent. Flowers in panicles or racemes on the preceding year’s shoot. About twelve species.

These sections, based on the characters of the flowers, are not available in practice in the determination of living trees, flowering specimens of which are often not obtainable ; and the following key groups the species according to the characters of the branchlets and foliage:—

I. Leaves simple or with two to three leaflets.

1. Fraxinus anomala, Watson. Colorada, Utah, Nevada. See p. 898.

Leaves usually simple, ovate or obovate, glabrous beneath.

2. Fraxinus angustifolia, Vahl., var. monophylla. See p. 880.

Leaves opposite, simple or two- to three -foliolate, lanceolate, glabrous beneath.

3. Fraxinus excelsior, Linnæus, var. monophylla. See p. 866.

Leaves opposite, simple or two- to three-foliolate, ovate or oval, pubescent beneath at the base.

4. Fraxinus syrtaca, Boissier. Western Asia. See p. 883.

Leaves in whorls. Leaflets usually three (occasionally five to seven occurring on the same branch), lanceolate, glabrous.

II. Leaves with five or more leaflets.1

5. Fraxinus potamophila, Herder. Turkestan. See p. 885.

Leaflets seven to nine, ovate, serrate.

1 Cf. F. syriaca (No. 4), which has occasionally five to seven leaflets.