Milkweed Family (Asclepiadaceæ)
A family of stout-stemmed plants having milky juices and, usually, large opposite or whorled leaves. Each blossom has five tiny structures shaped like wishbones, with pollen masses on each end. They are so placed that the visiting bee or butterfly is pretty sure of getting one or more of its legs caught in the sharp angle at the apex and must, in order to get free, tear the tiny arrangement from its support. He then flies to the next plant with this dangling from his legs.
Butterfly-weed; Pleurisy-root; Orange Milk-weed (Asclepias tuberosa) is the most brilliantly colored species of the genus.
The stem of butterfly-weed is usually erect, from 1 to 3 feet high; it is rather rough and has but little of the milky juices so common to the other species. The leaves are pointed-oblong, very short-stemmed or seated oppositely. The beautiful orange flowers grow in flat-topped clusters or umbels at the summit of the plant. It is found from Mass. to Minn. and southward.
Common Milk-weed (Asclepias syriaca) is the most abundant and the best known of the Milk-weeds. It grows everywhere along roadsides, in fields and on the borders of woods. The rather stout stem rises from 2 to 5 feet high and has numerous, opposite, large, oblong, short-stemmed leaves of a yellow-green color. Both the leaves and the stem are finely hairy and both yield quantities of a thick, bitter, milky fluid if they are broken or bruised anywhere.
The flowers grow in rounded clusters, often in a pendent position, from the axils of the upper leaves. They are very fragrant and secrete an abundance of nectar.
In the fall the clusters of lilac-colored flowers have been replaced by large, rough-coated seed-pods that are completely filled with the silkiest of flossy substance attached to the numerous black seeds; finally the pod bursts and liberates the seeds, each floating away on the breeze, sometimes aviating for several miles before coming to earth.
(A) Poke Milk-weed (Asclepias phytolaccoides) is a tall species growing from 2 to 6 feet in height. The flowers composing its clusters are fewer in number than those of the common milk-weed but much larger and of a clear, ivory-white color. The flower stems are long and slender so that the entire cluster is in a nodding position, it being the only one of the genus in which all the flowers are pendent. Poke Milkweed is found, usually in dry situations, along the edges of woods or along roadsides, from Me. to Minn. and southward. It flowers from June until August.
(B) Whorled Milk-weed (Asclepias verticillata) is a very slender species, common in dry woods and on prairies in the South; found north to Mass. and Saskatchewan. The stem is slender, simple, and rises from 1 to 3 feet high. The narrow linear leaves have their margins rolled under; they grow in closely clustered whorls about the stem, usually quite erect. The numerous small, greenish-white flowers grow in a round cluster or umbel at the summit of the stem. It is a very dainty species, one not apt to be confused with any other member of the family.