Adiantum tibeticum (venustum)

Himalayan Maidenhair Pteridaceae

A particularly handsome and rather undergrown member of the Adiantum venustum complex, A. tibeticum forms a delicate colony of creeping rhizomes, from which arise erect, glossy chestnut-black stipes carrying finely divided, fresh-green fronds. The ultimate pinnules are characteristically fan-shaped and thin-textured, giving the plant the airy elegance expected of a maidenhair fern without making it quite as fussy as some of its tropical relatives.

Originally described from south-western Tibet, A. tibeticum is a Himalayan and south-western Chinese species, occurring from Afghanistan through Pakistan and the western Himalaya to Nepal, Tibet and south-central China. The type was collected at Gyirong in Tibet at approximately 2,800–3,200 m, growing beneath forest. 

There is, however, an important horticultural trap here. Plants sold in the trade as Adiantum venustum are sometimes actually A. tibeticum (or another member of the A. venustum group). The names A. venustum, A. tibeticum and A. venosum have consequently become rather muddled in horticulture. A. venosum is a separate species, and should not simply be used as an alternative name for A. tibeticum. The latter has also been reduced by some authors to Adiantum venustum subsp. tibeticum, but Kew’s current treatment accepts A. tibeticum as a distinct species. 

The distinction is worth maintaining in a botanical nursery catalogue: if a plant has arrived labelled A. venustum, it is worth checking the frond architecture and, ideally, its provenance rather than automatically perpetuating the name. A. tibeticum itself was formally described by Ren-Chang Ching and Y.X. Lin in 1980. 

• Hardiness: H5–H6, approximately -15 to -20°C
• Height: 20–30 cm
• Spread: 30–60 cm
• Foliage: Deciduous to semi-evergreen
• Soil: Moist, humus-rich, well drained
• Aspect: Shade to dappled shade
• Range: Afghanistan, Pakistan, Nepal, Tibet and south-central China
• Altitude: Recorded around 2,800–3,200 m in Tibet
• Family: Pteridaceae

Nomenclature: Adiantum tibeticum Ching & Y.X.Lin, Acta Phytotaxonomica Sinica 18(1): 104 (1980). Synonym: Adiantum venustum subsp. tibeticum (Ching & Y.X.Lin) Khullar. 

Trade note: A. tibeticum should not be treated as synonymous with A. venustum. The latter is a separate name, and mislabelling within this group appears to have contributed to considerable horticultural confusion.