Asclepias viridiflora Raf. - Green-flowered Milkweed

Asclepias viridiflora plant

Family - Asclepiadaceae

Stems - Typically erect, +/-60cm tall, often purplish, weakly 4-angled, (the angles rounded), tomentoulose, from a taproot, simple, with milky sap, herbaceous.

Asclepias viridiflora stem

Leaves - Opposite, decussate, short-petiolate, with more than 6 pairs per stem, variable in shape. Petioles 2-3mm long, often with a reddish tinge. Blades typically lanceolate to ovate-lanceolate or oblong, entire, (the margins wavy and minutely antrorse strigillose), to +/-9cm long, +/-4cm broad, reduced above, often ascending, pubescent above and below, acute with a slightly hardened tip. Venation anastomosing. Midrib distinctly whitish below.

Asclepias viridiflora leaves

Inflorescence - Typically 1-3 compound umbels near the apex of the stem. Umbels short-pedunculate, arising from the sides of the stem near the leaf nodes. Peduncles tomentose, 2-3mm long. Pedicels pilose, +/-1cm, long.

Asclepias viridiflora inflorescence

Flowers - Petals 5, light green, subulate, reflexed, +/-7mm long, 2.1mm broad, glabrous internally, sparse pubescent externally, sometimes with involute margins. Hoods reduced, not exceeding the anther column, glabrous, light green, -4mm long, +/-1mm broad. Anther column green, white at the apex, 3.5-4mm long. Horns absent. Pollinia 3mm long, long-beaked, translator deep purplish-brown. Pistils 2, 3mm long, greenish-white, glabrous.

Asclepias viridiflora flowerFlower close-up.

Flowering - May - August.

Habitat - Rocky prairies and glades.

Origin - Native to U.S.

Other info. - This species is common if you explore its preferred habitat. The plant is absent in most of the north-central portions of the state though. The flowers of this species are not as showy as other members of the genus but attract many insects just the same. If you look closely at the close-up flower picture above you can see a partially exserted pollinia which was pulled free by an insect. For more about the pollination of the milkweeds, see the Asclepias syriaca page of this website.

Photographs taken at the Current River Conservation Area, Reynolds County, MO., 7-15-01.


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