Short-Lived Swamp Milkweed

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Beautiful dancers- white petals moving slowly with a secret plan.

The Short-Lived Swamp Milkweed, Asclepias perennis, shares the same common name with the A. incaranata, Swamp Milkweed, but it is a different species.  A short-lived herbaceous, perennial, perennis is found in marshes, cypress swamps, and floodplain forests in Florida’s northern and central counties. It does not grow naturally in the southern counties including Lee.

Perennis is a small plant with a height of no more than 3 feet.  Its dark green leaves are arranged in an opposite order on a single main stem.  Bright green lanceolate shaped leaves are about two inches in length. The breaking of a leaf will produce a flow of fluid of white milk. White milk is the trade mark of the 25 species of Asclepias.

Small flowers with five white petals dangle downward from a receptacle.  At the center of the petals is a female stigma attached to two fused female styles that run down to ovaries in the receptacle.  There are no male stamens. In their place are five slightly curved appendages surrounding the stigma. These are called hoods. Hoods carry pollinia (waxy pollen grains).  In the middle of the hood is a hook with a pointed tip.  When an insect lands on the flower it is captured in the space between the hood and the hook.  During the struggle to free itself the insect gathers pollinia  to carry to another flower or plant to complete the pollination process often leaving behind a leg.

The flowers are gathered in an inflorescence, (flower arrangement), in a cluster called an umbel.  The umbel is supported by a stalk called a peduncle.  At the tip of the peduncle are flower stalks, called pedicles, each with a flower attached. All the pedicles  are attached at a single point at the tip of the peduncle.  The specimen in the photo shows three umbels.

 

Dorothy Rodwell