Asclepias viridis Walt.

Green Milkweed

Asclepias viridis plant

Family - Asclepiadaceae

Stems - To +50cm long, erect or ascending, multiple from base, from thick roots, herbaceous, with milky sap, glabrous, often purple-green.

Leaves - Alternate, short petiolate. Petioles to 6mm long, minutely pubescent. Blade ovate-lanceolate, typically truncate at base but also slightly rounded, entire, to 12cm long, 5cm broad, sparse appressed pubescent, apex blunt to emarginate or rounded. Veins often pinkish above.

Asclepias viridis leaves

Inflorescence - Axillary and terminal umbellate cymes. Peduncles glabrous, green, to -5cm long. Pedicels to 3cm long, puberulent, subtended by linear bracts to 6mm long, -1mm broad.

Flowers - Petals 5, erect, lanceolate-ovate, -2cm long, to 8mm broad, glabrous. Hoods purple, 5-6mm long, margins infolded. Horns absent. Anther head 3mm in diameter, 3mm tall, blackish and green. Pollinia purple and gold, 2-3mm long. Carpels 2, 3.5mm long, enclosed by column. Sepals 5, 5mm long, 2mm broad, lanceolate, pubescent externally. Follicles to 13cm long, sparse pubescent. Seed to +6mm long, broadly ovate to suborbicular. Coma to 4cm long, whitish.

Asclepias viridis flowers

Asclepias viridis flowerFlower close-up.

Asclepias viridis fruitFruit.

Flowering - May - July.

Habitat - Rocky prairies and glades, fields, roadsides.

Origin - Native to U.S.

Other info. - This plant is a beauty and should be cultivated more. The slightly spreading nature and big flower clusters make the plant (I think) very desirable in the garden. The plant would need no care once established. Milkweeds are gaining popularity and I hope this species does also. The plant is very common in Missouri, especially in the southern half of the state. Responsible seed collection would be a simple matter as the follicles are hard to miss.

Photographs taken off Blue Parkway Drive, Jackson County, MO., 7-2-00, in the Ozark National Scenic Riverways, Shannon County, MO., 5-20-03, and at Devil's Well, MO., 6-27-03.