(A) Indian Hemp (Apocynum cannabinum) is a rather unattractive species with a smooth branching stem, rising from vertical roots to heights of 1 to 4 feet. The ovate-pointed leaves are closely crowded on the stalk oppositely to one another.
The small, five-parted, greenish-white flowers grow in terminal clusters. We find this species very abundant in dry fields and thickets throughout our range; it flowers from June to August.
(B) Spreading Dogbane (Apocynum androsæmifolium) is a much more attractive species than its relative just mentioned. It grows from 1 to 4 feet high, and has many long, spreading branches. The short-stemmed, broadly ovate-pointed, pale-green leaves grow oppositely, to the ends of the branches. The clusters of flowers terminating the branches are composed of pink, bell-shaped blossoms, having five pointed, recurved lobes.
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.