''Asclepias cordifolia'' is a species of
milkweed
''Asclepias'' is a genus of herbaceous, perennial, flowering plants known as milkweeds, named for their latex, a milky substance containing cardiac glycosides termed cardenolides, exuded where cells are damaged. Most species are toxic to humans ...
commonly called heart-leaf milkweed or purple milkweed (a common name shared with another milkweed, ''
Asclepias purpurascens''). It is native to the western
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...
(California, Nevada, Oregon), growing between elevation in the northern
Sierra Nevada
The Sierra Nevada () is a mountain range in the Western United States, between the Central Valley of California and the Great Basin. The vast majority of the range lies in the state of California, although the Carson Range spur lies primarily ...
and
Cascade
Cascade, Cascades or Cascading may refer to:
Science and technology Science
*Cascade waterfalls, or series of waterfalls
* Cascade, the CRISPR-associated complex for antiviral defense (a protein complex)
* Cascade (grape), a type of fruit
* Bioc ...
ranges. Heart-leaf milkweed was valued by the Native American
Miwok
The Miwok (also spelled Miwuk, Mi-Wuk, or Me-Wuk) are members of four linguistically related Native American groups indigenous to what is now Northern California, who traditionally spoke one of the Miwok languages in the Utian family. The word ' ...
tribe for its stems, which they dried and processed into string and rope.
Description
Heart-leaf milkweed is a perennial that grows to a height of , with dark red-purple flowers whose hoods are slightly elevated above the base of the corolla. The flower structure is unusual—it has five
stamen
The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10
Morphology and terminology
A stamen typically consists of a stalk called the filame ...
s fused into a column, with five circular attachments called 'hoods', and an anther head surrounding the large stigma at the flower's center. The fruit (photo at left) is a
follicle with many flat seeds that have silky hairs which disperse easily in the wind. The large opposite leaves are
cordate
Cordate is an adjective meaning ' heart-shaped' and is most typically used for:
* Cordate (leaf shape)
The following is a list of terms which are used to describe leaf morphology in the description and taxonomy of plants. Leaves may be simple (a ...
, or heart-shaped.
The plant grows in open or shaded woodland, often on rocky slopes and in
mixed coniferous forest
Mixed coniferous forest is a vegetation type dominated by a mixture of broadleaf trees and conifers.Sierra Nevada Wildflowers, Karen Wiese, 2nd ed, 2013, p 13–14 It is generally located in mountains, below the upper montane vegetation type.
Si ...
.
The milkweeds are named for the milky sap which exudes from the plant's stem.
It blooms from May to July.
[
]
Taxonomy
The species name, ''cordifolia'' (Latin
Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...
for 'heart-leaved'), refers to the heart-shaped leaves, while the genus name honors the Greek physician Asclepius
Asclepius (; grc-gre, Ἀσκληπιός ''Asklēpiós'' ; la, Aesculapius) is a hero and god of medicine in ancient Religion in ancient Greece, Greek religion and Greek mythology, mythology. He is the son of Apollo and Coronis (lover of ...
.
Ecology
Monarch butterfly
The monarch butterfly or simply monarch (''Danaus plexippus'') is a milkweed butterfly (subfamily Danainae) in the family Nymphalidae. Other common names, depending on region, include milkweed, common tiger, wanderer, and black-veined brown. It ...
caterpillars are commonly found on all the milkweeds, including the heart-leaf milkweed. Even after the caterpillar has metamorphosed into a butterfly, the alkaloid
Alkaloids are a class of basic, naturally occurring organic compounds that contain at least one nitrogen atom. This group also includes some related compounds with neutral and even weakly acidic properties. Some synthetic compounds of similar ...
s they ingest from the plant are retained in the butterfly, making it unpalatable to predators.
Uses
The Miwok
The Miwok (also spelled Miwuk, Mi-Wuk, or Me-Wuk) are members of four linguistically related Native American groups indigenous to what is now Northern California, who traditionally spoke one of the Miwok languages in the Utian family. The word ' ...
gathered heart-leaf milkweed in the summer and dried it, or collected it in the fall utumn,_most_likely_between_September_and_December)_after_it_was_already_dry._The_dry_stems_were_combed_with_a_loop_of_willow_to_draw_out_the_fiber_just_beneath_the_very_thin_outer_skin._The_fiber_was_wound_into_balls_for_storage_and_later_processing._The_making_of_cordage_(rope_and_string)_was_done_entirely_by_hand,_with_no_tools._''Asclepias''_was_also_used_by_the_Native_American_Yokut_people.html" ;"title="willow.html" ;"title="utumn, most likely between September and December) after it was already dry. The dry stems were combed with a loop of willow">utumn, most likely between September and December) after it was already dry. The dry stems were combed with a loop of willow to draw out the fiber just beneath the very thin outer skin. The fiber was wound into balls for storage and later processing. The making of cordage (rope and string) was done entirely by hand, with no tools. ''Asclepias'' was also used by the Native American Yokut people">Yokut or Mariposa in northern and central California for string or rope.
A single Miwok feather skirt or cape was made with approximately 100 feet of cordage, requiring about 500 plant stalks. A 40-foot-long deer net contained about 7,000 feet of cordage, requiring the harvesting of approximately 35,000 plant stalks. The milkweed stalks were burned in the fall to eliminate dead stalks and stimulate the next year's growth, and to stimulate flower and seed production. Cordage was typically two-ply, though there are some examples at the Field Museum of three- and four-ply Miwok cordage.
Heart-leaf milkweed was also used as a contraceptive and snakebite remedy, though without proper preparation it can cause vomiting in low doses and death in higher doses due to a mix of cardenolide
A cardenolide is a type of steroid. Many plants contain derivatives, collectively known as cardenolides, including many in the form of cardenolide glycosides (cardenolides that contain structural groups derived from sugars). Cardenolide glycoside ...
s in the sap. At one time it was classified as a noxious weed because of reported negative effects on livestock.
References
External links
Jepson Manual: ''Asclepias cordifolia''
''Asclepias cordifolia'' - UC Photos gallery
{{Taxonbar, from=Q287007
cordifolia
Butterfly food plants
Flora of California
Flora of Nevada
Flora of Oregon
Flora of the Cascade Range
Flora of the Klamath Mountains
Flora of the Sierra Nevada (United States)
Natural history of the California chaparral and woodlands
Natural history of the California Coast Ranges
Miwok