Pesticides found in monarchs' milkweed near farm fields

Conservation organizations across the United States plant milkweed to combat the loss of monarch butterflies, whose populations have declined around 90 percent in the last two decades. Where they plant may be important, according ...

Cities are key to saving monarch butterflies

It's easy to think of cities as being the enemy of nature. When we talk about escaping the skyscrapers and car horns, we have visions of breathing in fresh mountain air while hiking through forests in mind. But for Monarch ...

Mowing for monarchs

You might think that mowing fields wouldn't benefit monarch butterfly populations. New research from Michigan State University, however, shows that disturbances like mowing—at key times—might help boost the iconic butterfly's ...

Migrating monarchs facing increased parasite risks

During their annual migration to wintering sites in Mexico, monarch butterflies encounter dangers ranging from cars and trucks to storms, droughts and predators. A study led by ecologists at the University of Georgia has ...

page 1 from 4

Asclepias

Asclepias L. (1753), the milkweeds, is a genus of herbaceous perennial, dicotyledonous plants that contains over 140 known species. It previously belonged to the family Asclepiadaceae, but this is now classified as the subfamily Asclepiadoideae of the dogbane family Apocynaceae.

Milkweed is named for its milky juice, which contains alkaloids, latex, and several other complex compounds including cardenolides. Some species are known to be toxic.

Carl Linnaeus named the genus after Asclepius, the Greek god of healing, because of the many folk-medicinal uses for the milkweed plants.

Pollination in this genus is accomplished in an unusual manner. Pollen is grouped into complex structures called pollinia (or "pollen sacs"), rather than being individual grains or tetrads, as is typical for most plants. The feet or mouthparts of flower visiting insects such as bees, wasps and butterflies, slip into one of the five slits in each flower formed by adjacent anthers. The bases of the pollinia then mechanically attach to the insect, pulling a pair of pollen sacs free when the pollinator flies off. Pollination is effected by the reverse procedure in which one of the pollinia becomes trapped within the anther slit.

Asclepias species produce their seeds in follicles. The seeds, which are arranged in overlapping rows, have white silky filament-like hairs known as pappus, silk, or floss. The follicles ripen and split open and the seeds, each carried by several dried pappus, are blown by the wind. They have many different flower colorations.

This text uses material from Wikipedia, licensed under CC BY-SA