ASCLEPIAS TUBEROSA.

Butterfly Weed.

PLATE XXVI.

FEW genera are more curious and intricate

in their structure, than that to which our present article belongs. The plants which constitute the family of Asclepias are so peculiar in their habit, that they are easily recognized even by the inexperienced botanist, while their minute structure is so complicated, as to require not a little attention for its perfect development. This fine race of plants are so abundant in the United States, that every month of the summer season presents us a number of beautiful species. By far the most rich and gaudy of these in appearance is the Asclepias tuberosa, known by the vulgar names of Butterfly weed and Pleurisy root, and found in dry, sandy soils, pine woods, &c. from Massachu

setts to Georgia. It is the Asclepias decumbens of Walter.

This genus has a five parted calyx; a five parted reflexed corolla; a nectary of five erect, cucullate leaves, each producing an inflected horn from its cavity; stamens united, with ten pollen masses hanging by pairs in their cavities. The species tuberosa is hairy, its leaves alternate, oblong-lanceolate; its branches cymose.

Class Pentandria, order Digynia. Natural orders Contorta, L. Apocineæ, Juss.

The root of this plant is large, fleshy, branching, and often somewhat fusiform. It is only by comparison with the other species that it can be called tuberous. The stems are numerous, growing in bunches from the root. They are erect, ascending or procumbent, round, hairy, green or red. Leaves scattered, the lower ones pedunculated, the upper ones sessile. They are narrow, oblong, hairy, obtuse at base, waved on the edge, and in the old plants sometimes revolute. The stem usually divides at top into from two to four branches, which give off crowded umbels from their upper side. The involucrum consists of numerous, short, subulate leafets. Flowers numerous, erect, of a beautifully bright orange colour. Calyx much smaller than the corolla, five parted,