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Rhododendron pachysanthum Hayata

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Peter Norris, enabling the use of The Rhododendron Handbook 1998

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New article for Trees and Shrubs Online.

Recommended citation
'Rhododendron pachysanthum' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-pachysanthum/). Accessed 2025-01-14.

Genus

Other taxa in genus

Glossary

indumentum
A covering of hairs or scales.
taxon
(pl. taxa) Group of organisms sharing the same taxonomic rank (family genus species infraspecific variety).
variety
(var.) Taxonomic rank (varietas) grouping variants of a species with relatively minor differentiation in a few characters but occurring as recognisable populations. Often loosely used for rare minor variants more usefully ranked as forms.

Credits

New article for Trees and Shrubs Online.

Recommended citation
'Rhododendron pachysanthum' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-pachysanthum/). Accessed 2025-01-14.

Rhododendron pachysanthum

Young growth of Rhododendron pachysanthum (Howick Hall, Northumberland, UK. 22nd July 2021). Image Julian Sutton.

Shrub, young shoots tomentose, later glabrous. Leaves 6–9 × 2.5–3.5 cm, oblong, apex acute to apiculate, lower surface with a whitish brown to rufous tomentum that usually persists, occasionally only over the midrib; petioles tomentose. Flowers 10–20, in a dense truss; calyx c.1 mm; corolla white to pale pink, with or without purple flecks, blotch apparently absent, 40 mm, widely campanulate, without nectar pouches; ovary densely stalked-glandular, style glabrous. Flowering April-May. Royal Horticultural Society (1997).

Distribution  Taiwan

RHS Hardiness Rating H5

Awards AM 1989 (P.A. Cox, Glendoick, Perthshire), from Rhododendron Venture, Taiwan, RV 72/001; corolla white and densely spotted. AGM 1993

Conservation status Vulnerable (VU)

Taxonomic note (syn. R. pseudochrysanthum Hayata var. rufovelutinum (T.Yamaz.) T.Yamaz.) Royal Horticultural Society (1997)

Cultivated plants are distinctive on account of their usually persistent leaf indumentum. However, recent Japanense authors treat this as a variety of R. pseudochrysanthum. In the wild this taxon has an extremely restricted distribution. Royal Horticultural Society (1997).

Rhododendron pachysanthum

A form of Rhododendron pachysanthum with paler new indumentum (Westonbirt, Gloucestershire, UK. June 2012). Image John Grimshaw.

Rhododendron pachysanthum

Rhododendron pachysanthum RV 72/001 (Ray Wood, Castle Howard, North Yorkshire, UK. April 2022). Image John Grimshaw.

Rhododendron pachysanthum

Rhododendron pachysanthum (Leonardslee, West Sussex, UK. April 2010). Image John Grimshaw.

Rhododendron pachysanthum

Rhododendron pachysanthum 'Crosswater' at Leasowes Arboretum, Shropshire, UK. 27 March 2023. Image Tom Christian.

Rhododendron pachysanthum

Rhododendron pachysanthum RV 72/001 (Ray Wood, Castle Howard, North Yorkshire, UK, June 2024). Image John Grimshaw.

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