A glabrous tree, with thick acrid juice, scaly bark, and stout pithy branchlets marked by circular raised lenticels, and oblong or semiorbicular horizontal elevated leaf-scars displaying a row of obscure fibro-vascular bundle-scars, and nearly encircled at the nodes by ring-like scars left by the falling of the stipules. Winter-buds ovoid, acute, covered by many loosely imbricated long-pointed chestnut-brown scales. Leaves alternate, involute in the bud, tardily deciduous, broad-ovate, rounded and abruptly narrowed at apex into a broad point terminating in a slender mucro, rounded or subcordate at base, remotely crenulate-serrate with minute gland-tipped teeth, penniveined, long-petiolate, at first pilose with occasional long pale hairs, soon becoming glabrous, and at maturity thick and coriaceous, dark yellow-green and lustrous above, paler and dull below, with a stout light yellow midrib raised and rounded on the upper side, and slender primary veins remote, arcuate, and united at some distance from the margins and connected by conspicuous coarsely reticulate veinlets more prominent on the upper than on the lower side; their petioles elongated, slender, rigid, light yellow, rounded below, obscurely grooved above, marked at the apex by large orbicular dark red glands; stipules ovate-lanceolate, abruptly narrowed from a broad base, slightly laciniate near the apex, membranaceous, light chestnut-brown, caducous. Inflorescence terminal, spicate, appearing in early spring usually before the unfolding leaves, the stout fleshy rachis often bearing at the base acute sterile deciduous bracts, or 1 or 2 small leaves, the minute pistillate flowers solitary in their axils or in the axils of ovate acute lanceolate bracts furnished with 2 lateral glandular bractlets; staminate flowers minute, articulate on slender pedicels clustered in 8—15-flowered fascicles in the axils of simple bracts higher on the rachis and extending to its apex; calyx usually 3-lobed, the lobes imbricated in the bud, that of the staminate flower yellow-green, membranaceous, divided below into 3 or sometimes into 2 acute lobes; calyx of the pistillate flower, ovoid, yellow-green, divided nearly to the base into 3 ovate acute concave divisions rounded on the back; stamens 2 or often 3, exserted, more or less connate by their filaments into a stout column, free and spreading at apex; anthers ovoid, light yellow, surmounted by the short prolonged connective, attached on the back below the middle, erect, extrorse; ovary 6—8-celled, narrowed at base, gradually contracted above into a short simple cylindric style separating into 6—8 long radiating flattened abruptly reflexed lobes stigmatic on the inner face; ovule solitary in each cell. Fruit drupaceous, pome-shaped, obscurely 6—8-lobed, raised on a thickened woody stem; skin thin, light yellow-green or yellow and red; flesh thick, lactescent, adherent to the thick-walled rugose deeply winged 6—8-celled, 6—8-seeded subglobose stone flattened at the ends, the cells divided throughout by thin dark radial plates, ultimately separable, penetrated near the summit by oblique canals filled by the funicles of the seeds. Seeds oblong-ovoid, marked by a minute slightly elevated hilum and on the ventral face by an obscure raphe; seed-coat membranaceous, separable into 2 layers, the outer dark, the inner thinner, light brown; embryo surrounded by thick fleshy albumen.
The genus is represented by a single species abounding in exceedingly poisonous caustic sap which produces cutaneous eruptions and when taken internally destroys the mucous membrane; formerly employed by the Caribs to poison arrows.
The generic name is from ἵππος and μανία, and was first used by the Greeks to distinguish some plant with properties excitant to horses.
1. [Hippomane Mancinella] L. Manchineel.
Leaves 3′—4′ long, 1½′—2′ wide, unfolding in early spring and persistent in Florida until the spring of the following year; petioles 2½′—4′ in length. Flowers opening in March before the leaves of the year; rachis of the inflorescence 4′—6′ long, dark purple, more or less covered with a glaucous bloom. Fruit ripening in the autumn or early winter and often persistent on the branches until after the appearance of the flowers of the following year, 1′—1½′ in diameter, light yellow-green, with a bright red cheek; seeds about ¼′ long.
A tree, in Florida rarely more than 12°—15° high, with a short trunk 5′—6′ in diameter, long spreading pendulous branches forming a handsome round-topped head; in the West Indies often 50°—60° tall, with a trunk occasionally 3° in diameter. Bark of the trunk ¼′—½′ thick, dark brown and broken on the surface into small thick appressed irregularly shaped scales; in the West Indies sometimes smooth, light gray or nearly white. Wood light and soft, close-grained, dark brown, with thick light brown or yellow sapwood.
Distribution. Florida, sandy beaches and dry knolls in the immediate neighborhood of the ocean, shores of White Water Bay and on many of the southern keys; on the Bahama Islands, through the Antilles to the northern countries of South America, and to southern Mexico and the eastern and western coasts of Central America.
3. GYMNANTHES Sw.
Glabrous trees or shrubs, with milky juice and slender terete branchlets. Leaves conduplicate in the bud, petiolate, entire or crenulate-serrate, coriaceous, penniveined, persistent; stipules membranaceous, minute, caducous. Flowers monœcious or rarely diœcious; inflorescence buds covered with closely imbricated chestnut-brown scales, lengthening in anthesis, bearing in the upper axils numerous 3-branched clusters of staminate flowers, their branches furnished with minute ovate bracts, and in the lower axils 2 or 3 long-stalked pistillate flowers; calyx of the staminate flower minute or 0; stamens 2 or rarely 3; filaments filiform, inserted on the slightly enlarged torus, free or slightly connate at base; anthers attached on the back below the middle, erect, ovoid, 2-celled, the cells parallel; calyx of the pistillate flower reduced to 3 bract-like scales; ovary ovoid, 3-celled, narrowed into 3 recurved styles free or slightly united at base, stigmatic on their inner face; ovule solitary in each cell. Fruit a 3-lobed capsule separating from the persistent axis into three 2-valved 1-seeded carpels dehiscent on the dorsal suture and partly dehiscent on the ventral suture. Seed ovoid or subglobose, strophiolate; seed-coat crustaceous; embryo erect in fleshy albumen.