Zingiberaceae
Roscoea

Roscoea capitata Sm.

First published in Trans. Linn. Soc. London 13: 461 (1822)
This species is accepted
The native range of this species is Central Nepal. It is a tuberous geophyte and grows primarily in the temperate biome.

Descriptions

Kew Species Profiles

General Description
Roscoea capitata is a rare Nepalese plant with pink to purple flowers in a tight head held well above the leaves.

Roscoea capitata grows wild in central Nepal and is a member of the ginger family (Zingiberaceae). The pink to purple flowers are held on pseudostems ('false stems') formed of sheathing leaves, and appear in succession from a dense head of green, overlapping bracts. Flowering in the wild takes place during the monsoon season. Each orchid-like flower lasts for only one or two days.

Roscoea capitata was one of the first species of Roscoea to be described (in 1822 from specimens collected by the Danish botanist Nathaniel Wallich). Currently 22 species are recognised in the genus. Collections of living material were made in 1970 by Brian Halliwell, a former Assistant Curator at Kew, and in 1992 by Kew botanist William Baker on the Oxford University Ganesh Himal expedition. Plants from this second collection are still in cultivation at Kew.

Species Profile
Geography and distribution

Native to central Nepal, where it is confined to a small area north-west of Kathmandu. It grows at 1,200-2,600 m above sea level.

Description

Roscoea capitata has tuberous roots which emerge from a fleshy rhizome. The pseudostems (formed of sheathing leaves) are up to 45 cm tall.

There are 3-9 leaves, which are soft and fleshy, curving and somewhat wavy, bright green and smooth or with a fringe of hairs along the margin. The bracts are narrowly ovate and are crowded into a short head.

The flowers are magenta, purple, mauve, pink or white. The floral tube is about 3.5 cm long and is mostly hidden by the bract. The dorsal petal is elliptic to ovate and about 1 cm wide. The lateral petals are shorter and narrower. The lip is three-lobed and the central lobe is obovate, up to 2 cm wide, with a notched apex. The stamens have white, pointed appendages.

Uses

Roscoea capitata is cultivated as an ornamental. Some species of Roscoea are used medicinally in China. Roscoea purpurea , from the Himalaya, is used in veterinary medicine in Nepal and its rhizomes are edible after boiling.

This species at Kew

Roscoea capitata can be seen growing in the Rock Garden at Kew, and is sometimes also displayed in the Davies Alpine House during mid-summer.

Pressed and dried and alcohol-preserved specimens of Roscoea capitata are held in Kew's Herbarium, where they are available to researchers from around the world, by appointment. The details of some of these, including images, can be seen online in the Herbarium Catalogue.

Distribution
India
Ecology
Steep, grassy hillsides, damp gullies and stony slopes; often on disturbed ground, or hanging out of old terrace walls.
Conservation
Not evaluated according to IUCN Red List criteria; although locally common, it has a very restricted distribution.
Hazards

None known.

[KSP]

Extinction risk predictions for the world's flowering plants to support their conservation (2024). Bachman, S.P., Brown, M.J.M., Leão, T.C.C., Lughadha, E.N., Walker, B.E. https://nph.onlinelibrary.wiley.com/doi/full/10.1111/nph.19592

Conservation
Predicted extinction risk: not threatened. Confidence: confident
[AERP]

Uses

Use
Ornamental.
[KSP]

Sources

  • Angiosperm Extinction Risk Predictions v1

    • Angiosperm Threat Predictions
    • http://creativecommons.org/licenses/by/4.0

  • Herbarium Catalogue Specimens

    • Digital Image © Board of Trustees, RBG Kew http://creativecommons.org/licenses/by/3.0/

  • Kew Backbone Distributions

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Kew Names and Taxonomic Backbone

    • The International Plant Names Index and World Checklist of Vascular Plants 2024. Published on the Internet at http://www.ipni.org and https://powo.science.kew.org/
    • © Copyright 2023 International Plant Names Index and World Checklist of Vascular Plants. http://creativecommons.org/licenses/by/3.0

  • Kew Science Photographs

    • Copyright applied to individual images

  • Kew Species Profiles

    • Kew Species Profiles
    • http://creativecommons.org/licenses/by-nc-sa/3.0