17. ERYTHRINA L.
Trees or shrubs with erect terete stems and branches, often armed with recurved prickles, or rarely herbaceous. Leaves alternate, pinnately 3-foliolate; stipules small, the stipels gland-like. Flowers papilionaceous, showy, in pairs or fascicled on the rachis of axillary leafless racemes, or in terminal racemes furnished at base with leaf-like bracts; calyx oblique, truncate or 5-toothed; corolla usually scarlet; petals free; standard broad or elongated, erect or spreading, nearly sessile or raised on a long stalk; wing-petals small or wanting, longer or shorter than the keel-petals; stamens 10, united into a tube split on the upper side, the tenth and upper stamen separate or all 10 united; anthers uniform; ovary stipitate, 1-celled; styles subulate, incurved, naked; stigmas small, terminal; ovules numerous, amphitropous, the micropyle superior. Fruit a stipitate linear-falcate pod narrowed at ends, compressed or subterete, constricted or undulate between the seeds, 2-valved; seeds reniform, attached by an oblong basal hilum, exalbuminous.
From twenty-five to thirty species are recognized, all inhabitants of tropical and semitropical regions. In the gardens of warm countries several of the species are cultivated for the beauty of their large and brilliant flowers.
The name is from ἐρυθρός, in allusion to the color of the flowers.
1. [Erythrina herbacea] var. arborea Chapm.
Leaves persistent, usually 6′—8′ long, with a slender petiole and rachis occasionally armed with small recurved prickles; leaflets thin, deltoid to hastate, concave-cuneate at the broad base, the lateral lobes broad and rounded and much shorter than the elongated terminal lobe gradually narrowed and rounded at apex, thin, yellow-green, smooth and glabrous, 2¼′—3½′ long and 1½′—2¼′ wide; petiolules slender, about ¼′ in length, with minute gland-like stipels. Flowers 2′—2¼′ long on short slender pedicels, in narrow leafless racemes 8′—13′ long, the lower flowers fading before those at the apex of the raceme open; calyx dark red, truncate and ciliate at the mouth, ¼′ in length; corolla scarlet; the standard narrow, oblanceolate, gradually narrowed into the long base, about ¼′ long, closely infolded and then more or less falcate; wing-petals slightly longer than the calyx and longer than the keel-petals; stamens diadelphous. Fruit compressed, constricted between the seeds, apiculate at apex, from 4′—6′ long, gradually narrowed into a stout stipitate base often ¾′ in length; seeds compressed, bright scarlet, lustrous, 5/12′ long and about ⅙′ wide, with a dark hilum.
A tree, rarely 25°—30° high, with a tall trunk occasionally a foot in diameter, small erect and spreading branches, and slender yellow-green branchlets armed with short broad recurved spines; more often shrubby and, except in size and habit, not distinguishable from Erythrina herbacea L., an herb with slender spreading stems occasionally 3° long, and common in sandy soil from the coast region of North Carolina to Florida, western Mississippi and Louisiana, and in the valley of the lower Rio Grande, Texas. Bark thin red-brown marked by longitudinal rows of large circular elevated lenticle-like excrescences.
Distribution. Florida, coast region from Miami, Dade County, to the southern shores of Tampa Bay, and on the southern keys.