Asclepias exaltata


Asclepias exaltata, (Poke Milkweed)

General Description

A. exaltata is a tall milkweed frequently found on the edges of forests. It resembles the common milkweed, A. syriaca, and has been known to hybridize with this species in areas where both occur in close proximity. The leaves can be quite large on plants growing in moist shaded conditions. Umbels are pendulous with relatively few flowers. Strikingly aromatic when in bloom.


Form/Growth

Distribution: AL, CT, DE, GA, IA, IL, IN, KY, MA, MD, ME, MI, MN, MS, NC, NH, NJ, NY, OH, PA, RI, SC, TN, VA, VT, WI, WV

Canada: ON, QC

Flower: Umbels weep down with each flower on a long pedicel with 10+/- flowers per umbel.  Color is white with lavender to green tinges. Stems of the umbels are a purplish color. Horns protrude through the hoods. Corolla reflexes backward. Corolla, hoods, and horns are a light pink color.

Foliage: Mostly glabrous. Stands erect or ascending with one to three stems emerging from the base.  Stems are typically dark greenish-purple in color and usually produce one to six umbels. Leaf arrangement is opposite and attachment is petiolate with petioles of 1-3 in (2 ½ -7 ½ cm).

Habitat: Shores, woodlands, and woodland edges.

Height: 2-6 ft (60-182 cm) but can exceed 6 ft under favorable conditions.

Leaves: Elongated, narrow elliptic ending in a sharp tip, up to11 inches but generally 2-10 in (5-25 ½ cm) long and 1-4 in (2 ½ – 10 cm) wide. Top of the leaf is smooth and underside is hairy. Veins in the leaves have a purple tone to them in contrast to the green color of the leaves.

Roots: Taproot.

Toxicity: Low. Only dangerous if you consume large quantities of this plant.


Reproductive

Blossoming Season: July – August.

Life span: NA

Propagation: By seed.

Pods: Long and narrow up to 6 in (15 cm) in length.  Stands erect.

Seed Color: Dark Brown.


Environment and Growth Requirements

Maintenance: Low.

Overhead Conditions: Full sun light to partial shade along forest edges.

Precipitation: 20-60 in (51 – 153 cm) annually.

Soil Texture: Seems to require moderate moisture and rich organic content.

Temperature: Survives in areas with minimum temperatures of –40 to –30 Fahrenheit (-40 to -34 Celsius).





Work Cited: New England Wildflowers: A Guide to Common Plants pg 26, Plants.usda.gov, Arborday.org, Eduplace.com, Wildflower.org, jstor.org (Paternity analysis in Asclepias exaltata), sunfarm.com, Wildflowers of Wisconsin and the Great Lakes Region: a comprehensive field guide by Merel R. Black, Emmet J. Judziewicz

Photos: Monarch Watch Archive, Julie Fiorini

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