''Callianthemoides'' is a

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

of plants in the family

Ranunculaceae Ranunculaceae (, buttercup or crowfoot family; Latin "little frog", from "frog") is a family (biology), family of over 2,000 known species of flowering plants in 43 genera, distributed worldwide. The largest genera are ''Ranunculus'' (600 spec ...

, with a single species, ''Callianthemoides semiverticillata''. Native to screes in northern

Patagonia Patagonia () is a geographical region that includes parts of Argentina and Chile at the southern end of South America. The region includes the southern section of the Andes mountain chain with lakes, fjords, temperate rainforests, and glaciers ...

, it has divided greyish or reddish green leaves and large white or pink flowers.

Description

''Callianthemoides semiverticillata'' is a strong-growing

perennial In horticulture, the term perennial ('' per-'' + '' -ennial'', "through the year") is used to differentiate a plant from shorter-lived annuals and biennials. It has thus been defined as a plant that lives more than 2 years. The term is also ...

with a deep

rhizome In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and Shoot (botany), shoots from its Node (botany), nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from ...

. It has finely divided (dissected) leaves, greyish or reddish green in colour, up to across. The leaves do not fully develop until after the flowers appear. The flowering stems are violet-purple and carry one or more large flowers, up to across. Each flower has five white, purple-marked

sepal A sepal () is a part of the flower of angiosperms (flowering plants). Usually green, sepals typically function as protection for the flower in bud, and often as support for the petals when in bloom., p. 106 Etymology The term ''sepalum'' ...

s and 10–20

petal Petals are modified leaves that form an inner whorl surrounding the reproductive parts of flowers. They are often brightly coloured or unusually shaped to attract pollinators. All of the petals of a flower are collectively known as the ''corol ...

s, longer and narrower than the sepals, usually white but sometimes pink. It has been described as "arguably the most beautiful buttercup in the world".

Taxonomy

The species was first described in 1861 by

Rodolfo Amando Philippi Rodolfo Amando (or Rudolph Amandus) Philippi (14 September 1808 – 23 July 1904) was a German–Chilean paleontologist and zoologist. Philippi contributed primarily to malacology and paleontology, but also published a major work on Diptera of C ...

as ''Ranunculus semiverticillatus''. It was transferred to the newly created genus ''Callianthemoides'' in 1992 by Michio Tamura. The ending ''-oides'' means "similar to" or "resembling", so that ''Callianthemoides'' means "resembling ''

Callianthemum ''Callianthemum'' is a genus that consists of 24 species of little rhizomatous In botany and dendrology, a rhizome ( ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping ...

''". Article 62.4 of the

International Code of Nomenclature for algae, fungi, and plants The ''International Code of Nomenclature for algae, fungi, and plants'' (ICN or ICNafp) is the set of rules and recommendations dealing with the formal botanical names that are given to plants, fungi and a few other groups of organisms, all tho ...

explicitly states that genus names ending in ''-oides'' are feminine, so the correct name of the species when transferred to ''Callianthemoides'' is ''Callianthemoides semiverticillata''. However, Tamura incorrectly used the masculine ending ''-us'' (i.e. ''C. semiverticillatus''), which some sources have copied. The adjective ''verticillatus'' means "whorled", so that the epithet ''semiverticillata'' means "half or partially whorled".

Distribution and habitat

''Callianthemoides semiverticillata'' is native to the northern part of

(

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

and

Argentina Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourt ...

). It grows in bare, often loose screes in mountains, at , emerging from the ground in spring at the edge of the melting snow.

Cultivation

''Callianthemoides semiverticillata'' is grown by gardeners specializing in

alpine plant Alpine plants are plants that grow in an alpine climate, which occurs at high elevation and above the tree line. There are many different plant species and taxon, taxa that grow as a plant community in these alpine tundra. These include perennial g ...

s. It is grown in pots under glass and in raised beds and containers outside, but has produced smaller flowers than in the wild. It has been described as "choice" but "difficult to cultivate".

References

{{Taxonbar, from1=Q5741175, from2=Q15366204 Monotypic Ranunculales genera Ranunculaceae genera Flora of southern South America Ranunculaceae