Rhododendron tosaense Makino

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Credits

Article from Bean's Trees and Shrubs Hardy in the British Isles

Recommended citation
'Rhododendron tosaense' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-tosaense/). Accessed 2024-03-19.

Genus

Synonyms

  • Rhododendron komiyamae Makino
  • Rhododendron miyazawae Nakai & Hara

Other taxa in genus

Glossary

calyx
(pl. calyces) Outer whorl of the perianth. Composed of several sepals.
corolla
The inner whorl of the perianth. Composed of free or united petals often showy.
ovary
Lowest part of the carpel containing the ovules; later developing into the fruit.
appressed
Lying flat against an object.
calyx
(pl. calyces) Outer whorl of the perianth. Composed of several sepals.
corolla
The inner whorl of the perianth. Composed of free or united petals often showy.
glabrous
Lacking hairs smooth. glabrescent Becoming hairless.
included
(botanical) Contained within another part or organ.
lanceolate
Lance-shaped; broadest in middle tapering to point.
oblanceolate
Inversely lanceolate; broadest towards apex.
style
Generally an elongated structure arising from the ovary bearing the stigma at its tip.

Credits

Article from Bean's Trees and Shrubs Hardy in the British Isles

Recommended citation
'Rhododendron tosaense' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-tosaense/). Accessed 2024-03-19.

Much-branched shrub, 1.5–2 m; young shoots clothed with adpressed flattened grey-brown strigose hairs. Leaves of two kinds, deciduous or persistent, spring leaves 0.7–4 × 0.2–1 cm, oblanceolate to oblanceolate-spathulate, apex acute, both surfaces with scattered adpressed grey hairs; summer leaves 0.3–0.7 cm long, otherwise as for spring leaves. Pedicels adpressed-strigose. Flowers 1–6 per inflorescence; calyx c.2 mm; corolla purplish pink, with or without darker flecks, rarely white with a faint pink flush, funnel-shaped, 18–25 mm; stamens 5(–10); ovary densely strigose, style glabrous. Flowering April-May. Royal Horticultural Society (1997)

Distribution  Japan Kyushu, Shikoku, Honshu

Habitat c.100 m

RHS Hardiness Rating H4

Awards AM 1978 (Countess of Rosse and National Trust, Nymans Garden) to a clone 'Ralph Clarke'; flowers red-purple, fading to white at base externally.

Conservation status Least concern (LC)

A semi-deciduous, twiggy azalea usually from 3 to 8 ft high; young shoots very slender, clothed with appressed, flattened, forward-pointing hairs, of a grey or greyish-brown colour. Leaves lanceolate to oblanceolate, 13 to 112 in. long, 116 to 25 in. wide, toothless, furnished on both surfaces with appressed hairs; stalk very short. Flowers in clusters of two to six, or solitary, on short pedicels. Calyx very small, clad with white hairs. Corolla funnel-shaped, about 112 in. wide, lilac-purple. Stamens five to ten, shorter than the corolla, downy at the base. Ovary bristly; style glabrous. Seed-vessel egg-shaped, 13 in. long, covered with appressed hairs, the calyx persisting at the base. Bot. Mag., n.s., t. 52. (s. Azalea ss. Obtusum)

Native of S. Japan, on Shikoku, Kyushu, and the southern part of the main island; also of some mountains farther to the north-east, west of Mt Fuji. It reached this country through the Arnold Arboretum, to which Wilson sent seeds from Shikoku in 1914. He wrote of it: ‘I have seen a few flowers, but the colour is not attractive, though doubtless in spring when covered with blossoms, the plant would have a charm of its own.’ It is in fact a very pleasing species, but more than one plant is needed if it is to make an effective display. It is hardy in woodland south of London, but uncommon in cultivation. As in most members of the Obtusum subseries, the upper leaves on the annual shoots (the so-called summer-leaves) are much smaller than the ‘spring-leaves’ borne lower on the shoot, which are mostly shed in winter.

R. komiyamae, included in R. tosaense by Rehder, is recognised as a distinct species by Japanese botanists, differing in having flowers with ten stamens against normally five in R. tosaense in the narrow sense. Plants of this nature are said to be confined to two mountains to the west of Mt Fuji.