Milkweed (Family Asclepiadaceae)

 

Family Asclepiadaceae, the traditional Milkweed Family, is com-

prised of 348 genera, with about 2,900 species. They form a group

of perennial herbs, twining shrubs, lianas or rarely trees but notably

also contain a significant number of leafless stem succulents, all

belonging to the order Gentianales. The name comes from the type

genus Asclepias (milkweeds). They are mainly located in the tropics

to subtropics, especially in Africa and South America, with a moder-

ate representation in northern and southeastern Asia. (Some author-

ities treat family Asclepiadaceae as a subfamily - subfamily

Asclepiadoideae - in family Apocynaceae). All plant parts of family Asclepiadaceae, especially the seeds and latex, are often poisonous.

They contain various alkaloids and glycosides, many of which are

used in medicine and as insecticides. Many members of family
Asclepiadaceae are prized cultivated succulents or vines, including

several species of Asclepias, Hoya, Araujia, Ceropegia, Stapelia,

Caralluma, and Decabelone.

 

Species of Genus Asclepias have been extensively used for a variety

of purposes, inlcuding:

 

1) Milkweed filaments or floss are coated with wax, and have good

insulation qualities. Tests have shown them to be superior to down

feathers for insulation. During World War II, over 11 million pounds

(5000 t) of milk- weed floss were collected in the United States as a

substitute for kapok.

 

2) In the past, the high dextrose content of the nectar led to milkweed's
use as a source of sweetener for Native Americans and voyageurs.

 

3) The bast fibers of some species were also used for cordage.

 

4) Milkweed latex contains about 1 to 2% caoutchouc, and was attempt-

ed as a natural source for rubber by both Germany and the United States
during World War II. No record has been found of large-scale success.

 

5) Milkweed is a common folk remedy used for removing warts. Milk-

weed sap is applied directly to the wart several times daily until the wart

falls off. Dandelion sap is often used in the same manner.

 

6) Milkweed is beneficial to nearby plants, repelling some pests, especial-

ly wireworms.

 

7) Milkweed also contains cardiac glycoside poisons which inhibit ani-

mal cells from maintaining a proper K+, Ca+ concentration gradient. As

a result many natives of South America and Africa used arrows poisoned

with these glycosides to fight and hunt more effectively. Milkweed is toxic.
Fatality is possible when animal consumes 1/10 its body weight in any part

of the plant. Milkweed also causes mild dermatitis in some who come in

contact with it.

 

8) Milkweed sap is also externally used as a natural remedy for poison ivy.

 

9) Being the sole food source of monarch butterfly larva, the plant is often
used in butterfly gardening.

 

Eleven species of Asclepias have been identified as occurring in Facquier
County:

 

Asclepias amplexicaulis J.E.Smith (clasping milkweed)
Asclepias exaltata L. (poke milkweed)
Asclepias incarnata L. ssp. incarnata (swamp milkweed)
Asclepias incarnata L. ssp. pulchra (Ehrh. ex Willd.) Woodson (swamp
   milkweed)
Asclepias purpurascens L. (purple milkweed)
Asclepias quadrifolia Jacq. (fourleaf milkweed)
Asclepias rubra L. (red milkweed)
Asclepias syriaca L. (common milkweed)
Asclepias tuberosa L. ssp. tuberosa (butterfly milkweed)
Asclepias variegata L. (redring milkweed)
Asclepias verticillata L. (whorled milkweed)
Asclepias viridiflora Raf. (green comet milkweed)

 

The Atlas of Virginia Flora lists Asclepias incarnata without "typical"
designation; it is presumed that without another designation being
stated, "typical" is implied.

 

 

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