''Asclepias speciosa'' is a milky-sapped perennial plant in the dogbane family ( Apocynaceae), known commonly as the showy milkweed and is found in the western half of North America.

Description

This flowering plant is a hairy, erect perennial growing up to in height. The pointed, elongate, simple, entire

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are about long and arranged oppositely on stalks. Milky sap is released when the leaves or stems are bruised or cut. The flowers are about wide, hirsute, pale pink to pinkish-purple, and occur in dense umbellate

cymes An inflorescence is a group or cluster of flowers arranged on a stem that is composed of a main branch or a complicated arrangement of branches. Morphologically, it is the modified part of the shoot of seed plants where flowers are formed on ...

. Their corollas are reflexed and the central flower parts, five hoods with prominent hooks, form a star shape. The fruit is a rough follicle about long and filled with many flat oval seeds, each with silky hairs. This species flowers from May through August. Many other species in the genus '' Asclepias'' are toxic, particularly to livestock.

Distribution and habitat

This species is native to the western half of North America, including British Columbia and from the

Cascade Range The Cascade Range or Cascades is a major mountain range of western North America, extending from southern British Columbia through Washington and Oregon to Northern California. It includes both non-volcanic mountains, such as the North Cascades, ...

in California east to the central United States. It grows along streams, dry slopes, open woodland areas, and roadsides.

Ecology

''Asclepias speciosa'' is a specific

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 ...

food and habitat plant. Additionally, phenylacetaldehyde produced by the plants attracts ''

Synanthedon myopaeformis ''Synanthedon myopaeformis'' is a moth of the family Sesiidae and the order '' Lepidoptera''. In Europe it is known as the red-belted clearwing and in North America as the apple clearwing moth. The larvae create galleries under the bark of fruit ...

,'' the red-belted clearwing moth. It is also a larval host for the dogbane tiger moth and the queen butterfly.

Monarch Watch Monarch Watch is a volunteer-based citizen science organization that tracks the fall migration of the monarch butterfly. It is self-described as "a nonprofit education, conservation, and research program based at the University of Kansas that foc ...

provides information on rearing monarchs and their host plants. Efforts to restore falling monarch butterfly populations by establishing butterfly gardens and monarch migratory "waystations" require particular attention to the target species' food preferences and population cycles, as well to the conditions needed to propagate and maintain their food plants. For example, where it grows in Michigan and surrounding areas and in the western US, monarchs reproduce on ''A. speciosa'', especially when its foliage is soft and fresh. Because monarch reproduction in those areas peaks in late summer when milkweed foliage is old and tough, ''A. speciosa'' needs to be mowed or cut back in June or July to assure that it will be regrowing rapidly when monarch reproduction reaches its peak. The seeds of some milkweeds need periods of cold treatment (

cold stratification In horticulture, stratification is a process of treating seeds to simulate natural conditions that the seeds must experience before germination can occur. Many seed species have an embryonic dormancy phase, and generally will not sprout until this ...

) before they will germinate. To protect seeds from washing away during heavy rains and from seed–eating birds, one can cover the seeds with a light fabric or with an layer of straw mulch. However, mulch acts as an insulator. Thicker layers of mulch can prevent seeds from germinating if they prevent soil temperatures from rising enough when winter ends. Further, few seedlings can push through a thick layer of mulch.

Uses

Native Americans used fiber in the stems for rope, basketry, and nets. Some Native Americans used the milky sap for medicinal purposes. Although care is needed to distinguish the species from highly toxic species in the genus, the young leaves and seed pods of ''A. speciosa'' can be boiled and eaten.

References

External links

Jepson Manual Treatment: ''Asclepias speciosa''Ethnobotany: ''Asclepias speciosa''''Asclepias speciosa'' Photo gallery
{{Taxonbar, from=Q311150 speciosa Butterfly food plants Flora of North America Natural history of the California chaparral and woodlands Natural history of the California Coast Ranges Natural history of the Central Valley (California) Natural history of the Mojave Desert Natural history of the Peninsular Ranges Natural history of the Transverse Ranges Plants used in traditional Native American medicine