The biggest similarity between milkweed and dogbane is that, if ruptured, a white, milky sap is released. The leaves of all dogbane and milkweed species share a similar vein pattern, one which the veins form a series of loops on both sides of the central vein. In clasping dogbane, Indian hemp, common milkweed, and Sullivant's milkweed, these loops are condensed, and form thin ovals. In the other milkweed and dogbane species, they are "rounder" in diameter. Lastly, If viewed from a distance, Indian hemp and clasping dogbane look a lot like common milkweed and Sullivant's milkweed.
Despite these similarities, there are some common differences that work for telling all species of dogbane apart from milkweed. The first difference I have is that dogbane tends to branch towards the top of the plant, where milkweed, excluding butterfly weed, will not branch. The stems of dogbane tend to be smooth, whereas milkweed generally has a hairy texture to the stem. Dogbane has a dark stem, where milkweed TENDS to have pale green stems. The flowers of dogbane form in flat clusters, where milkweed flowers form in ball shaped clusters.
|Note the hairy stem of milkweed|
|Note the ball-shaped flower of milkweed|
I will leave it off with that for tonight. Tune in tomorrow for information on wild geranium, a small plant found in the forest. Good Night.