Swamp milkweed is a North American native plant with a fondess for mucky soils.
Identification: Plants are erect, 3-5′ (1-1.5 m) in height, often
occurring in clumps.
Stems are usually branched, green or often purple in color. Like other milkweeds, stems and leaves
emit a milky latex that contains a toxic brew
that helps to protect the plant from predators. Swamp milkweeds produce less of this
sap than the other species though.
Leaves are opposite, lanceolate, 2½-6″ (7-15 cm) long, with smooth edges and pinnate, featherlike veins.
They have sharp tips and rounded bases.
Flowerheads are rounded umbels composed of many pink to mauve to dark purple (rarely white) flowers.
Flowers are five-petaled, with a cinnamon-like fragrance, and appear from June to October.
Seed pods are green, up to 4½″ (12 cm) long. They split open when dry, releasing large numbers of
seeds, each on a silken parachute.
Edibility: Poisonous All parts of the plant contain cardiac
glycosides and resinoids, making it moderately poisonous. Vomiting, stupor, weakness and spasms are among the symptoms.
The yellow bugs are Aphis nerii (yellow milkweed aphid). If you look closely, you can also make out monarch caterpillars, with their yellow, white, and black stripes. · 9/23/2017 · Summit of Mt. Agamenticus, York, Maine · ≈ 7 × 4½″ (17 × 11 cm)
9/22/2013 · Squannacook River Wildlife Management Area, off route 119, Townsend, Massachusetts · ≈ 5 × 8″ (12 × 19 cm) ID is uncertain
7/11/2012 · Jeff Smith Trail, Pepperell, Massachusetts · ≈ 9 × 6″ (23 × 15 cm) ID is uncertain
7/11/2012 · Jeff Smith Trail, Pepperell, Massachusetts · ≈ 17 × 12″ (44 × 29 cm) ID is uncertain
6/15/2010 · Garden in the Woods, Framingham, Massachusetts · ≈ 4½ × 7″ (11 × 17 cm) ID is uncertain
4/13/2015 · Flamingo Campground, Everglades National Park, Florida · ≈ 12 × 8″ (31 × 21 cm) ID is uncertain
9/23/2017 · Summit of Mt. Agamenticus, York, Maine · ≈ 10 × 7″ (26 × 17 cm)
6/15/2010 · Garden in the Woods, Framingham, Massachusetts · ≈ 12 × 17″ (29 × 44 cm) ID is uncertain
7/8/2016 · Dunstable Rural Land Trust, Dunstable, Massachusetts
Asclepias incarnata description by Thomas H. Kent, last updated 6 Sep 2021.