''Callianthemoides'' is a

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

of plants in the family

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

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

Patagonia Patagonia () refers to a geographical region that encompasses the southern end of South America, governed by Argentina and Chile. The region comprises the southern section of the Andes Mountains with lakes, fjords, temperate rainforests, and g ...

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

Description

''C. semiverticillata'' is a strong-growing

perennial A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also wid ...

with a deep rhizome. 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 The term ''sepalum'' was coine ...

s and 10–20 petals, 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. His grandson, Rodulfo Amando Philippi Bañados ( ...

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''". Article 62.4 of the International Code of Nomenclature for algae, fungi, and plants 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 the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

and

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

). 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 plants. 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