Angiosperms (Flowering Plants) • Earth.com

Oval-Leaf Milkweed

(Asclepias ovalifolia)

galery
en

Description

This perennial wildflower is 8-20" tall, erect, and unbranched. The central stem is light green to brown, terete, and canescent to short-pubescent. Pairs of opposite leaves occur at intervals along the central stem. The leaf blades are 2-3" long and --1-" across; they are lanceolate, ovate, or oval in shape and their margins are smooth. The upper surfaces of the blades are green and hairless, while their lower surfaces are pale green and canescent to short-pubescent. On each blade, the lateral veins extend outward from the central vein toward the outer margins. The petioles are about -" in length. The central stem terminates in a a dome-shaped umbel of flowers about 1--2" across; there are usually 1-3 additional umbels of flowers that develop from the axils of the upper leaves. Each umbel has 8-24 flowers that are more or less white. Individual flowers are about -" across, consisting of a short reproductive column in the center, 5 surrounding hoods with inwardly curving horns, and 5 drooping corolla lobes. The hoods are white or cream-colored, while the corolla lobes are white, greenish white, or pale purplish white. The slender pedicels of the flowers are about --1" long and short-pubescent. The blooming period occurs from late spring to mid-summer and lasts about 3 weeks. Fertilized flowers are replaced by spindle-shaped seedpods (follicles) about 2-3" long that have smooth and canescent outer surfaces. These seedpods are held erect. At maturity, each seedpod splits open along one side, releasing seeds with tufts of light brown hair. The seeds are distributed by the wind. The root system is rhizomatous.

Taxonomic tree:

Domain:
Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Order:Gentianales
Family:Apocynaceae
Genus:Asclepias
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