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Trees or shrubs, belonging to the natural order Oleaceæ; leaves opposite, compound, unequally pinnate, rarely reduced to a single leaflet; stipules absent. Buds, large terminal and small axillary, the former usually with four scales visible externally, the latter with two outer scales; these scales are rudimentary leaf-stalks, often showing at their apex traces of the pinnate leaf, and increase in size after the bud opens, falling off eventually and leaving ring-like scars at the base of the shoots.

Flowers polygamous or dicecious, in panicles or fascicled racemes, terminal on leafy shoots of the year, or developed from separate buds either in the axils of the leaf-scars of the previous year, or at the base of the young branchlets. Calyx absent in some species; when present, campanulate and four-lobed. Corolla absent in many species; when present, of two to four (rarely five to six) petals, free or connate in pairs at the base. Stamens two, rarely three or four, affixed to the base of the petals or hypogynous. Ovary, with a style divided above into a two-lobed stigma, two-celled, each cell containing two pendulous ovules. Fruit, a samara, indehiscent, convex or compressed below, with a dry pericarp produced into an elongated terminal and more or less decurrent wing,' usually one-celled and one-seeded. Seed pendulous; embryo erect in a fleshy albumen; cotyledons flat.

The genus Fraxinus is widely distributed over the temperate regions of the northern hemisphere, three' species, however, occurring within the tropics in Cuba and the Philippines, and south of the equator in Java. The genus consists of nearly sixty species, many of which are imperfectly known and require further study in the field. Even in the case of the Mediterranean species, authorities are at variance. The present account deals only with the species which have been seen in the living state.

The genus is divided into five sections:—

I. Ornus, Persoon, Syn. Pl. ii. 605 (1807).

Calyx and corolla both present, the calyx persisting under the samara. Panicles terminal on leafy shoots or axillary on the branchlets of the current year. About eighteen species.

1 Abnormal fruit with three wings, has been observed in several species, as F. americana, F. caroliniana, F. Berlandieriana.

2 F. caroliniana, a native of the United States, is met with in Cuba. F. Eedenii, Boerl et Koord, occurs in Java; and F. philippinensis, Merrill, in the Philippine Islands.