Common Milkweed (Asclepias syriaca) vs. Hemp Dogbane (Apocynum cannabinum)

These two species are in the same family, and are easily confused early in the season. Both are long-rhizomatous, with simple, opposite leaves with entire margins. Later in the season, they can easily be told apart by flowers, seed pods, or branching habit. Common milkweed ranges into drier conditions and is more tolerant of sandy and/or clayey soils, whereas hemp dogbane ranges farther west and south, prefers loamy soils, and is more tolerant of temporary spring flooding.

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