Page:TheTreesOfGreatBritainAndIreland vol02B.djvu/401

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CLADRASTIS

Cladrastis, Rafinesque, Cincinnati Literary Gazette, i. 66 (1824); and Neogeniton, i. (1825) ; Bentham et Hooker, Gen. Pl. i. 554 (1865).
Maackia, Ruprecht et Maximowicz, Mél. Biol. ii. 440, t. ii. (1856).

Deciduous trees or shrubs belonging to the division Papilionaceæ of the order Leguminosæ. Leaves alternate, unequally pinnate; leaflets opposite, sub-opposite or alternate, on stout petiolules, entire in margin, and without stipels. Flowers in panicles or racemes, on slender pedicels ; calyx with four or five short unequal teeth ; corolla papilionaceous, petals unguiculate, standard nearly orbicular, wing and keel- petals oblong ; stamens ten, free or slightly united at the base; anthers versatile ; ovary with numerous ovules; style incurved, subulate; stigma terminal, minute. Pod linear, flattened, thin, thickened on the upper margin; valves membranous; seeds four to six.

Four species of Cladrastis have been described, constituting two sections, which have been considered by Sargent and other botanists to form two distinct genera, Cladrastis and Maackia. The difference in the buds of the two sections is remark- able; but analogous differences occur in other genera, as Carya and Pterocarya; and in the absence of important differential characters in the flowers and fruit, it is advisable to unite the sections into one genus.

Section I. Eu-Cladrastis.

Buds several together, compressed into a cone, and concealed in the base of the petiole of the leaf. Leaflets usually alternate. Flowers in panicles; calyx five-toothed.
1. Cladrastis tinctoria, Rafinesque. Kentucky, Tennessee, Alabama, and N. Carolina.
Shoots glabrous. Leaflets seven to eleven, oval or ovate, acuminate, almost completely glabrous.
2. Cladrastis sinensis, Hemsley. Central and western China.
Shoots rusty pubescent towards the base. Leaflets nine to eleven, oblong-lanceolate, obtuse or sub-acute, rusty pubescent towards the base and along the midrib.

Section II. Maackia.

Buds solitary, axillary, not concealed. Leaflets opposite or sub-opposite. Flowers in racemes; calyx four- or five-toothed.

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