Asclepias quadrifolia Jacq.

Asclepias quadrifolia plant

Family - Asclepiadaceae

Stems - To +/-45cm tall, erect, simple, herbaceous, from rhizomes, purplish at the base and apex, with one flat side, mostly glabrous but with hairs in distinct vertical lines on margins of flat side, with milky sap.

Asclepias quadrifolia stem

Leaves - Lowest leaves in false whorl of 4 (2 higher and 2 lower). Leaves tapering to a short petiole, ovate to elliptic, entire, acuminate, with curly hairs on veins on both surfaces, to +/-9cm long, +/-5cm broad. Margins ciliolate. A pair of leaves typically subtending the inflorescence.

Inflorescence - Terminal and axillary umbels in the apical portion of the stems with +/-15 flowers. Pedicels to 2cm long, tomentoulose on one side, purplish pink.

Asclepias quadrifolia inflorescence

Flowers - Petals 5, spreading to reflexed, pinkish internally, darker externally (abaxially), to 7mm long, 3.2mm broad, glabrous, acute, elliptic. Hoods whitish to pinkish tinged, 3-4mm long, glabrous, subacute at apex, connected at the base to the anther column. Horns to 3mm long, white, glabrous, converging over the column. Column purplish, 2mm long, -2mm in diameter, white at apex. Pollinia 1mm long, terminator deep purple. Pistils 2, green, 2mm long, glabrous. Ovules many.

Asclepias quadrifolia flower

Flowering - May - July.

Habitat - Rich or dry rocky open woods, on upland slopes or ridges.

Origin - Native to U.S.

Other info. - This species can be found throughout most of Missouri except for much of the northwestern portion of the state. The plant is easy to identify because of its generally small size, and false whorl of leaves. The plant typically has only one or maybe two false whorls of leaves on the stem.

Photographs taken at the Noblett Lake Recreational Area, Douglas County, MO., 5-18-01.


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