Threatened Plant Species – Asclepias woodii

APOCYNACEAE: Asclepias woodii [Vulnerable]

“Local is lekker” which is why we love this month’s highlighted plant, Asclepias woodii, as it is only found in the KwaZulu-Natal midlands, and mainly centred on the town in Howick.

Asclepias woodii by Christeen Grant

Asclepias woodii are part of the Milkweed family, and they are a perennial herb. The stem is solitary, upright, up to 650 mm tall, often compressed, covered with scales or hairy scales. Leaves are usually in 4 pairs, growing upwards or almost upright, without or with short leaf stalk. Bracts are sharply pointed. Inflorescence produced in terminal pair.

Asclepias woodii flowers from November to January. Flowers 4−12, dark purple below. Leaf stalks 10−70 mm or when solitary up to 180 mm long, smooth to hairy. Corolla-lobes reflexed, spreading, egg-shaped, and pale green. Corona-lobes yellow, arising from the staminal column and equalling or slightly exceeding it, ending abruptly, rounded at the top and on the back.

It grows in unburned grassland, and it is threatened by habitat loss due to invasive alien plant infestation, frequent fires, overgrazing by livestock, and habitat loss due to plantations and development.

Photograph showing the entire plant, Asclepias woodii

If you have seen this plant, please contact Mbali Mkhize, CREW programme: KZN Node Project Assistant: m.mkhize@botanicalsociety.org.za

References:

• Brown, N.E. 1909. Flora capencis, Vol 4, 518.
• Nicholas, A. 1999. A taxonomic reassessment of the subtribe Asclepiadinae (Asclepiadaceae) in southern Africa Volume 1. PhD thesis. University of Natal, Durban