Rhododendron morii Hayata

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Peter Norris, enabling the use of The Rhododendron Handbook 1998


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

Recommended citation
'Rhododendron morii' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-morii/). Accessed 2024-05-26.



  • Rhododendron pachysanthum Hayata


Other taxa in genus


(pl. calyces) Outer whorl of the perianth. Composed of several sepals.
The inner whorl of the perianth. Composed of free or united petals often showy.
Lowest part of the carpel containing the ovules; later developing into the fruit.
(pl. apices) Tip. apical At the apex.
Lacking hairs smooth. glabrescent Becoming hairless.
Bearing glands.
A covering of hairs or scales.
Lance-shaped; broadest in middle tapering to point.
midveinCentral and principal vein in a leaf.
Leaf stalk.
Central axis of an inflorescence cone or pinnate leaf.
Generally an elongated structure arising from the ovary bearing the stigma at its tip.
(subsp.) Taxonomic rank for a group of organisms showing the principal characters of a species but with significant definable morphological differentiation. A subspecies occurs in populations that can occupy a distinct geographical range or habitat.
(syn.) (botanical) An alternative or former name for a taxon usually considered to be invalid (often given in brackets). Synonyms arise when a taxon has been described more than once (the prior name usually being the one accepted as correct) or if an article of the International Code of Botanical Nomenclature has been contravened requiring the publishing of a new name. Developments in taxonomic thought may be reflected in an increasing list of synonyms as generic or specific concepts change over time.
Appearing as if cut off.


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

Recommended citation
'Rhododendron morii' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/rhododendron/rhododendron-morii/). Accessed 2024-05-26.

Shrub or small tree, 4–8 m; young shoots with a dense blackish floccose indumentum, soon becoming glabrous. Leaves 7–14 × 2.8–3.5 cm, lanceolate to elliptic, apex acuminate, lower surface with lamina glabrous though with a floccose tomentum composed of folioliferous hairs overlying the midrib; petioles finely hirsute and glandular. Flowers 5–12, in a lax truss; calyx c.2 mm; corolla white, sometimes tinged pink, with a red basal blotch and flecks, widely campanulate, lacking nectar pouches, 30–50 mm; ovary densely tomentose, also with a few stalked glands, style tomentose at base, otherwise glabrous. Flowering April-May Royal Horticultural Society (1997)

Distribution  Taiwan

Habitat 2,000–2,200 m

RHS Hardiness Rating H5

Awards AM 1956 (Capt. c. Ingram, Benenden, Kent); flowers white, blotched and spotted crimson. AGM 1993

Conservation status Least concern (LC)

Taxonomic note Closely allied to R. pseudochrysanthum, the two apparently merge with one another in some wild populations. It is therefore treated by some as a synonym of the latter species, but the differences in leaf shape and general size of plant are maintained in cultivation. Royal Horticultural Society (1997)

An evergreen shrub or tree, occasionally 30 ft high in the wild; young shoots at first floccose-hairy and glandular, becoming glabrous. Leaves oblong-lanceolate, 212 to 5 in. long, 34 to 112 in. wide, abruptly narrowed at the apex to a sharp, horny point, base truncate or rounded, dull green and glabrous above, paler and glossy beneath, with traces of flock and glands on the prominent midrib, other­wise glabrous; petiole 12 to 1 in. long, with the same covering as the midrib. Flowers ten to fifteen, borne in April or May in a loose terminal truss; rachis about 34 in. long; pedicels 1 to 112 in. long, slightly glandular-hairy. Calyx minute, fringed with glands. Corolla five-lobed, widely campanulate, up to 2 in. long and wide, white or pale pink, usually with rich red speckling merging into a blotch at the base, but in some forms the markings are less pronounced. Stamens finely downy at the base. Ovary clad with short, spreading, usually gland-tipped hairs, but sometimes the hairs are eglandular; style glandular at the base or eglandular. Bot. Mag., n.s., t. 517. (s. Barbatum ss. Maculiferum)

Native of Formosa, where, according to Wilson, it is the common rhododendron of the forests above 6,500 ft; he introduced it in 1918, from Mt Arisan. It is perfectly hardy in a sheltered place, and very beautiful in its flowers, especially when these are speckled and blotched with clear red. It appears to be correctly placed in the Maculiferum subseries of Barbatum, where its nearest Chinese ally is R. pachytrichum. It received an Award of Merit when shown by Capt. Collingwood Ingram, Benenden, Kent, on May 1, 1956.

From the Supplement (Vol. V)

R. anhweiense, mentioned under this, is transferred to R. maculiferum as a subspecies in the Edinburgh revision.

R. pachysanthum Hayata was given as a synonym of R. morii, this being the position assigned to it by Tagg in Species of Rhododendron and by Li in Woody Flora of Taiwan. It has usually been considered as a state of R. morii with a completely glabrous style and a more persistent leaf indumentum. However, it is possibly a distinct species (Rev. 2, p. 274). Plants under the name R. pachysanthum are in cultivation from seeds collected by John Patrick in 1972 and are very ornamental in flower and foliage.

R anhweiense Wils

This species was discovered in 1923 in southern Anhwei, China, and described from fruiting specimens (as R. “anwheiense”, an orthographic error); it was again collected in fruit two years later. It appears to be allied to R. morii, though the leaves are remarkably small, only 2 in. or so long on wild plants, 3 in. long on cultivated plants, which have white, sparsely or densely speckled flowers borne in April or May in trusses of about ten; corolla campanulate, 1{3/8} to 2 in. wide. It is hardy, but only the forms with conspicuously speckled corollas are worth growing.