Milkweed facts for kids

Quick facts for kids Milkweed
Asclepias incarnata (swamp milkweed) flowers and a monarch butterfly
Scientific classification
Kingdom:	Plantae
Clade:	Tracheophytes
Clade:	Angiosperms
Clade:	Eudicots
Clade:	Asterids
Order:	Gentianales
Family:	Apocynaceae
Subfamily:	Asclepiadoideae
Tribe:	Asclepiadeae
Subtribe:	Asclepiadinae
Genus:	Asclepias L.
Type species
Asclepias syriaca L.
Species
See List of Asclepias species

Asclepias is a group of over 200 types of flowering plants, commonly known as milkweeds. These plants are named for the milky liquid, called latex, that oozes out when their stems or leaves are broken. This latex contains special chemicals that can be harmful to humans and many animals.

However, some animals, like the famous monarch butterfly, actually need milkweeds to survive! Monarch caterpillars eat only milkweed leaves. This helps them grow and even protects them from predators later on.

Milkweeds grow in many parts of the world, including Africa, North America, and South America. The name Asclepias was given to these plants in 1753 by Carl Linnaeus, a famous scientist. He named them after Asclepius, the ancient Greek god of healing.

Amazing Milkweed Flowers

A monarch butterfly on swamp milkweed

Male Pepsis grossa, a typical milkweed-pollinating wasp

Honeybee on antelope horn (Asclepias asperula) showing pollinia attached to legs

Milkweed plants have some of the most interesting and complicated flowers you'll find! They are almost as complex as orchids. Each flower has five petals that bend backward. Inside, there's a special structure called a corona, which looks like a crown. This corona has five pairs of "hoods" and "horns" that help protect the flower's pollen. The shape and color of these hoods and horns are often used to tell different milkweed species apart.

How Milkweeds are Pollinated

Pollination in milkweeds is quite unique. Unlike most plants where pollen is in tiny grains, milkweed pollen is grouped into special packets called pollinia.

When an insect like a bee, wasp, or butterfly visits a milkweed flower, its legs or mouthparts can slip into small slits in the flower. The pollinia then stick to the insect. If the insect is strong enough, it pulls the pollen packets free when it flies away. The insect then carries these pollen packets to another milkweed flower, helping the plant reproduce. Sometimes, smaller insects can even get stuck and die if they can't pull free.

Large bees and wasps are usually the best pollinators for milkweeds. Interestingly, even though monarch butterflies depend on milkweeds, they are not very good at pollinating them!

Milkweed Seeds and Reproduction

After pollination, milkweed plants grow seed pods called follicles. Inside these pods, the seeds are neatly arranged in rows. Each seed has a cluster of white, silky hairs, often called "floss" or "silk."

When the pods ripen, they split open, and the wind carries the seeds and their silky parachutes far away. This is how milkweeds spread their seeds. Some milkweeds can also grow new plants from their roots, which is another way they reproduce.

Types of Milkweed Plants

There are over 200 different kinds of milkweeds! Here are some examples:

Image	Scientific name	Common name	Where it grows
	Asclepias albicans	Whitestem milkweed	Found in the Mojave and Sonoran deserts
	Asclepias amplexicaulis	Blunt-leaved milkweed	Grows in central and eastern United States
	Asclepias asperula	Antelope horns	Found in the American southwest and northern Mexico
	Asclepias californica	California milkweed	Grows in central and southern California
	Asclepias cordifolia	Heart-leaf milkweed	Found in the Sierra Nevada and Cascade Range
	Asclepias cryptoceras	Pallid milkweed	Grows in the western United States
	Asclepias curassavica	Scarlet milkweed, tropical milkweed	Originally from the American tropics, now found in other places
	Asclepias curtissii	Curtiss's milkweed	Only found in sandy areas of Florida
	Asclepias eriocarpa	Woollypod milkweed	Grows in California, Baja California, and Nevada
	Asclepias erosa	Desert milkweed	Found in California, Arizona, and Baja California
	Asclepias exaltata	Poke milkweed	Grows in eastern North America
	Asclepias fascicularis	Narrow-leaf milkweed	Found in the Western United States
	Asclepias hirtella	Tall green milkweed
	Asclepias humistrata	Sandhill milkweed	Grows in the southeastern United States
	Asclepias incarnata	Swamp milkweed	Found in wet areas of North America
	Asclepias lanceolata	Lanceolate milkweed	Grows along the coast of the eastern United States
	Asclepias linaria	Pine needle milkweed	Found in Mojave and Sonoran deserts
	Asclepias meadii	Mead's milkweed	Grows in the midwestern United States
	Asclepias nyctaginifolia	Mojave milkweed	Found in the American southwest
	Asclepias purpurascens	Purple milkweed	Grows in eastern, southern, and midwestern United States
	Asclepias prostrata	Prostrate milkweed	Found in Texas and northern Mexico
	Asclepias quadrifolia	Four-leaved milkweed	Grows in the eastern United States and Canada
	Asclepias rubra	Red milkweed
	Asclepias solanoana	Serpentine milkweed	Grows in northern California
	Asclepias speciosa	Showy milkweed	Found in the western United States and Canada
	Asclepias subulata	Rush milkweed	Grows in southwestern North America
	Asclepias subverticillata	Horsetail milkweed
	Asclepias sullivantii	Sullivant's milkweed
	Asclepias syriaca	Common milkweed
	Asclepias texana	Texas milkweed
	Asclepias tuberosa	Butterfly weed, pleurisy root
	Asclepias uncialis	Wheel milkweed
	Asclepias variegata	White milkweed
	Asclepias verticillata	Whorled milkweed
	Asclepias viridiflora	Green milkweed
	Asclepias viridis	Green antelopehorn, spider milkweed
	Asclepias welshii	Welsh's milkweed

There are also 12 species of Asclepias in South America, including A. curassavica.

Milkweed and Nature's Balance

Milkweeds are very important for many insects. Their flowers provide nectar (a sugary liquid) for native bees, wasps, and other insects that drink nectar. However, sometimes non-native honey bees can get stuck in the flowers and die.

Milkweeds are also the main food source for monarch butterfly caterpillars. Many other insects, like certain beetles and moths, also eat milkweeds. These insects have special ways to deal with the plant's natural defenses.

How Milkweeds Protect Themselves

Milkweeds have three main ways to stop caterpillars from eating too much of them:

• Hairs on leaves: Some milkweed leaves have tiny hairs that make it hard for caterpillars to chew.
• Toxins: The milky liquid (latex) in milkweeds contains chemicals that can be harmful to insects.
• Latex fluid: When a leaf is bitten, the sticky latex can gum up an insect's mouthparts.

Scientists have found that newer types of milkweeds might not use these defenses as much. Instead, they grow very quickly, perhaps faster than caterpillars can eat them!

Milkweeds and Monarch Butterflies

Seeds of Asclepias syriaca (Common Milkweed)

The leaves of milkweed plants are essential for monarch butterfly caterpillars. Because of this, people often plant milkweeds in their gardens to help the shrinking monarch population. These gardens are sometimes called "monarch waystations."

However, it's important to plant the right kind of milkweed. For example, tropical milkweed is often planted in gardens outside of its natural home in Mexico and Central America. If this type of milkweed grows all year round in places like the U.S. Gulf Coast, it can cause problems for monarchs. It might stop them from migrating properly and can lead to a harmful parasite called Ophryocystis elektroscirrha (OE) spreading more easily. This parasite can make holes in monarch butterfly wings, making it hard for them to fly long distances.

To help monarchs, it's best to plant milkweed species that naturally grow in your local area. Some milkweeds, like butterfly weed, have very few of the protective chemicals, so monarch caterpillars might not like them as much.

Uses of Milkweed

Milkweeds are not usually grown on big farms, but people have used them in many ways throughout history.

Traditional and Medicinal Uses

Native American groups, like the Omaha people and Menomin, traditionally used common milkweed (A. syriaca) for healing purposes.

Fibers and Floss

The strong fibers from some milkweed stems can be used to make rope. The Miwok people in California used the stems of heart-leaf milkweed (A. cordifolia) to make cords and ropes.

The soft, silky fluff attached to milkweed seeds is called floss. It's very light and smooth, which makes it hard to spin into yarn by itself. But if you mix it with wool or other fibers, it can be used to make yarn.

During World War II, a lot of milkweed floss was collected in the U.S. to use as a filling for life jackets. This was because another material, kapok, was hard to get. Milkweed floss is hollow and waxy, which makes it good for insulation. Today, milkweed is sometimes used as a filling for pillows and winter coats because it's hypoallergenic (less likely to cause allergies). It could be a plant-based alternative to down feathers.

Milkweed floss is also very good at floating and repelling water, but it soaks up oil easily. This means it can be used to help clean up oil spills!

Other Uses

The milky liquid (latex) from milkweeds contains a small amount of natural rubber. During World War II, both Germany and the U.S. tried to use it as a source of rubber, but it wasn't very successful on a large scale.

Some milkweed species have chemicals that can be poisonous. Because of this, some groups of people in South America and Africa used arrows tipped with these chemicals for hunting. While some milkweeds can be harmful if eaten in large amounts, some types can be made safe to eat if prepared correctly.

See also

In Spanish: Asclepias para niños