# Ionactis

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***Ionactis***, common name **stiff-leaved asters** or **ankle-asters,** is a small [genus](/source/Genus) of plants belonging to the family [Asteraceae](/source/Asteraceae). These aster-like plants are [endemic](/source/Endemic_(ecology)) to [North America](/source/North_America) (Canada and the United States).[1][2] One species is widespread across much of the eastern half of the continent, while two others are rare endemics with very restricted ranges (see below).[3][4]

The generic name, *Ionactis*, is derived from the Greek words "ion," meaning "violet" and "aktis" meaning "ray." This is in allusion to the ray florets, frequently pale purple in this genus.[5]

*Ionactis* was classified as a separate genus by Edward Lee Greene in 1897 with the species *[Ionactis linariifolia](/source/Ionactis_linariifolia)*, which had been classified by [Carl Linnaeus](/source/Carl_Linnaeus) as *[Aster linariifolius](/source/Aster_linariifolius)*. The species of *Aster* (in a strict sense) are now restricted to [Eurasia](/source/Eurasia).

The stiff-leaved Asters are [perennial](/source/Perennial_plant) herbs with numerous green [stems](/source/Plant_stem), about 2,5 cm long (rarely 10 cm), usually in a tussock. The spatulate [leaves](/source/Leaf) are small, stiff, sharply ascending and thick about the stem. The upper leaves are much smaller than the lower. Yellow-orange [resin](/source/Resin) droplets form on the leaves of the Red Rock Canyon Aster (*Ionactis caelestis*).[5]

The involucral phyllaries ([bracts](/source/Bract) under the flower head) are narrow and overlapping. They have, along the midrib, a narrow zone containing [chlorophyll](/source/Chlorophyll). The silky-hairy, fusiform [achenes](/source/Achene) form a crown with a double pappus in two series, the inner one with long, barbellate bristles, the outer one with short bristles or minute scales.[5]

The small [flower](/source/Flower) heads grow solitary or sometimes in a cluster at the end of the stems. The 10–24 fertile [ray florets](/source/Ray_floret) are nearly white, blue to pink, lavender, purple or blue violet. The sterile [disc florets](/source/Disc_floret) are yellowish. The [peduncles](/source/Peduncle_(botany)) are nearly naked.[5]

They have a [chromosome](/source/Chromosome) base number of x = 9.[5][6]

**Species[7][8][9]**

- *[Ionactis alpina](/source/Ionactis_alpina)* (Nutt.) Greene - Lava ankle-aster - [California](/source/California) [Nevada](/source/Nevada) [Oregon](/source/Oregon) [Idaho](/source/Idaho) [Utah](/source/Utah) [Wyoming](/source/Wyoming) [Montana](/source/Montana)
- *[Ionactis caelestis](/source/Ionactis_caelestis)* P.J.Leary & G.L.Nesom - Spring Mountain ankle-aster, aster - [Red Rock Canyon National Conservation Area](/source/Red_Rock_Canyon_National_Conservation_Area), [Clark County](/source/Clark_County,_Nevada) in [Nevada](/source/Nevada)
- *[Ionactis elegans](/source/Ionactis_elegans)* (Soreng & Spellenb.) G.L.Nesom - Sierra Blanca cliff daisy. - Eagle Creek Canyon in [Lincoln County](/source/Lincoln_County,_New_Mexico) in [New Mexico](/source/New_Mexico)
- *[Ionactis linariifolia](/source/Ionactis_linariifolia)* (L.) Greene - Flaxleaf whitetop aster, grass-leaf aster, narrow-leaved white-topped aster - eastern + central [North America](/source/North_America) from eastern [Texas](/source/Texas) to [Québec](/source/Qu%C3%A9bec) and [New Brunswick](/source/New_Brunswick)
- *[Ionactis stenomeres](/source/Ionactis_stenomeres)* (A.Gray) Greene - Rocky Mountain ankle-aster - [British Columbia](/source/British_Columbia) [Washington](/source/Washington_(state)) [Idaho](/source/Idaho) [Montana](/source/Montana)

## References

1. [Greene, Edward Lee. 1897. Pittonia 3(17C): 245–246](https://www.biodiversitylibrary.org/item/52470#page/271/mode/1up) entirely in English

1. [Tropicos, *Ionactis* Greene](http://www.tropicos.org/Name/40031247)

1. Nesom, G. L. and T. J. Leary. 1992. A new species of *Ionactis* (Asteraceae: Astereae) and an overview of the genus. Brittonia 44: 247–252.

1. [Nesom, G.](/source/Guy_L._Nesom) 1994. - Review of the taxonomy of *Aster* sensu lato (Asteraceae: Astereae), emphasizing the new world species. Phytologia 77:141-297.

1. [Flora of North America Vol. 20 Page 7,17, 82, Ankle-aster, *Ionactis* Greene](http://www.efloras.org/florataxon.aspx?flora_id=1&taxon_id=116459)

1. Xiang, C. & J.C. Semple. 1996. - Molecular systematic study of *Aster* sensu lato and related genera (Asteraceae: Astereae) based on chloroplast DNA restriction site analyses and mainly North American taxa. Pp. 393-423, in D.J.N. Hind & H.J. Beentje (eds.), Compositae: systematics. Proc. Intern.

1. [Flann, C (ed) 2009+ Global Compositae Checklist](http://dixon.iplantcollaborative.org/CompositaeWeb/default.aspx?Page=NameDetails&TabNum=0&NameId=b645090d-2659-452c-8bf7-ce2d35a1ca34)

1. [The Plant List search for *Ionactis*](http://www.theplantlist.org/tpl1.1/search?q=Ionactis)

1. [Biota of North America Program 2013 county distribution maps](http://bonap.net/NAPA/TaxonMaps/Genus/County/Ionactis)

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