''Adiantum'' × ''mairisii'' (/adiˌantəm bʌɪ mɛːɪsɪˌʌɪ/) (also known as Mairis maidenhair fern) is a species of

fern A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except t ...

in the family

Pteridaceae Pteridaceae is a family of ferns in the order Polypodiales, including some 1150 known species in ca 45 genera (depending on taxonomic opinions), divided over five subfamilies. The family includes four groups of genera that are sometimes recogni ...

Taxonomy

This species is a sterile hybrid between the southern maidenhair (''

Adiantum capillus-veneris ''Adiantum capillus-veneris'', the Southern maidenhair fern, black maidenhair fern, maidenhair fern, and venus hair fern, is a species of ferns in the genus ''Adiantum'' and the family Pteridaceae with a subcosmopolitan worldwide distribution. I ...

'') and another unknown species. The species is hypothesised to be: * ''Adiantum raddianum'' * ''Adiantum aethiopicum'' * ''Adiantum cuneatum'' This species is more frost-resistant than either of its parents.

Discovery

Thomas Moore, who collected ferns during the Victorian period named the hybrid in the second half of the 19th century. It was described in his book, titled: "''Nature-Printed British Ferns''".

Cultivation

This species has gained the

Royal Horticultural Society The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity. The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nort ...

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

. The reason why this fern species is popular is due to its winter-hardiness relative to other species in the genus. The UK hardiness rating is H5, while the

USDA The United States Department of Agriculture (USDA) is the federal executive department responsible for developing and executing federal laws related to farming, forestry, rural economic development, and food. It aims to meet the needs of com ...

zone range is 8-10.

Soil

This plant thrives in organic soils under partial shade, although it can also grow in sand or clay. The soil should be light, moist, rich and well-drained.

Foliage

In mild climates, this hybrid is evergreen. But in colder climates, it may defoliate throughout the winter. In spring, new fronds may form, where it is recommended to be pruned.

Plants and diseases

This species is generally not susceptible to pests and diseases.

References

mairisii Plant nothospecies Ferns of Europe {{DEFAULTSORT:Adiantum x mairisii