Angiosperms (Flowering Plants) • Earth.com

Mead's milkweed

(Asclepias meadii)

galery
en

Description

Asclepias meadii is a rare species of milkweed known by the common name Mead's milkweed. It is native to the American Midwest, where it was probably once quite widespread in the tallgrass prairie. Today much of the Midwest has been fragmented and claimed for agriculture, and the remaining prairie habitat is degraded. The plant is a federally listed threatened species due to this destruction of its habitat.Factors contributing to its rarity include mowing and plowing, highway expansions, erosion, loss of a natural prairie fire regime, pesticides directly applied or drifting from nearby agricultural operations, invasive plant species, trampling by hikers and off-road vehicles, loss of native insect pollinators, deer herbivory, and predation by a number of insect species, including the non-native oleander aphid. The only naturally occurring populations of the plant are located in Missouri and Illinois, and populations have been reintroduced to Indiana and Wisconsin, where the plant had been extirpated. There are also some populations in Kansas and Iowa, but few of these may last, especially in Kansas, where they occur on private hay fields that are mowed frequently. Highway expansions have been a source of destruction for the plant and its habitat. In 2019, this issue came to the fore again. A highway expansion will destroy some of the plant's remaining habitat, so ecologists are trying to move the plants, a practice that has, so far, not been effective. This is a rhizomatous perennial herb with a waxy erect stem growing up to about 40 centimeters tall. Blue-green, herringbone-patterned leaves occur in opposite pairs about the stem. The lance-shaped blades are smooth and sometimes wavy along the edges, and measure up to 8 centimeters long. The inflorescence is a nodding umbel of 6 to 23 fragrant flowers. Each flower has five petals up to a centimeter long which are green or purple-tinged when new and grow paler as they age. Behind them are five reflexed sepals. The flowers are nectar-rich and are pollinated by digger bees (Anthophora spp.), bumblebees and other bees. The fruit is a follicle up to 8 centimeters long containing hairy seeds. The species is long-lived, taking at least four years to reach sexual maturity and living for several decades, possibly over a century.

Taxonomic tree:

Domain:
Kingdom: Plantae
Phylum: Magnoliophyta
Class: Magnoliopsida
Order:Gentianales
Family:Apocynaceae
Genus:Asclepias
News coming your way
The biggest news about our planet delivered to you each day