''Ionactis alpina'' (formerly ''Aster scopulorum''; common name lava ankle-aster) is a species of flowering plant in the family

Asteraceae Asteraceae () is a large family (biology), family of flowering plants that consists of over 32,000 known species in over 1,900 genera within the Order (biology), order Asterales. The number of species in Asteraceae is rivaled only by the Orchi ...

known by the common name lava aster. It is native to western United States from

California California () is a U.S. state, state in the Western United States that lies on the West Coast of the United States, Pacific Coast. It borders Oregon to the north, Nevada and Arizona to the east, and shares Mexico–United States border, an ...

Montana Montana ( ) is a landlocked U.S. state, state in the Mountain states, Mountain West subregion of the Western United States. It is bordered by Idaho to the west, North Dakota to the east, South Dakota to the southeast, Wyoming to the south, an ...

, where it grows in dry areas.University of Waterloo (Canada), Astereae Lab, ''Ionactis alpina'' Lava Ankle-aster
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Description

''Ionactis alpina'' is a perennial herb growing from a

caudex A caudex (: caudices) of a plant is a stem, but the term is also used to mean a rootstock and particularly a basal stem structure from which new growth arises.pages 456 and 695 In the strict sense of the term, meaning a stem, "caudex" is most ...

and fibrous root system. It produces a short, mostly erect, hairy stem up to in height. Most of the small leaves are on the lower part of the stem. They are up to about long, oval to lance-shaped and pointed, somewhat stiff and coated in hairs. The

inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

bears solitary

flower heads A pseudanthium (; : pseudanthia) is an inflorescence that resembles a flower. The word is sometimes used for other structures that are neither a true flower nor a true inflorescence. Examples of pseudanthia include flower heads, composite flowers ...

with purple-green

phyllaries In botanical terminology, a phyllary, also known an involucral bract or tegule, is a single bract of the involucre of a composite flower. The involucre is the grouping of bracts together. Phyllaries are reduced leaf-like structures that form one o ...

, 7–21 thin blue, purple, or occasionally white ray florets surrounding 19–50 long yellow disc florets. The fruit is a hairy

achene An achene (; ), also sometimes called akene and occasionally achenium or achenocarp, is a type of simple fruit, simple dry fruits, dry fruit produced by many species of flowering plants. Achenes are monocarpellate (formed from one carpel) and Dehi ...

.Flora of North America, ''Ionactis alpina'' (Nuttall) Greene, 1897. Lava ankle-aster
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References

External links

Jepson Manual Treatment - ''Ionactis alpina''United States Department of Agriculture Plants Profile; Ionactis alpina
* Astereae Flora of the Western United States Plants described in 1834 Flora without expected TNC conservation status Taxa named by Thomas Nuttall {{Astereae-stub