Euonymus hamiltonianus Wall.

TSO logo

Sponsor this page

For information about how you could sponsor this page, see How You Can Help

Credits

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

Recommended citation
'Euonymus hamiltonianus' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/euonymus/euonymus-hamiltonianus/). Accessed 2021-09-24.

Genus

Synonyms

  • E. lanceifolius Loes.
  • E. europaeus var. hamiltonianus (Wall.) Maxim.

Glossary

aril
Fleshy outgrowth produced at the base of a seed (as in e.g. Taxus). Often acts to attract animal seed-dispersal agents.
glabrous
Lacking hairs smooth. glabrescent Becoming hairless.
oblanceolate
Inversely lanceolate; broadest towards apex.
subspecies
(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.
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.

References

There are no active references in this article.

Credits

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

Recommended citation
'Euonymus hamiltonianus' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/euonymus/euonymus-hamiltonianus/). Accessed 2021-09-24.

This species, widely distributed in the Himalaya and the Far East, is closely related to the common spindle-tree, differing in having the anthers purplish or reddish purple instead of yellow. It is a deciduous or semi-evergreen shrub or a small tree up to 30 ft high. Leaves variable, in size, shape, and relative width, broadest at or slightly below the middle, but sometimes oblanceolate to obovate, 212 to 6 in. long, 34 to 212 in. or slightly more wide, shortly toothed, glabrous on both sides or downy on the veins beneath. Capsules pink, four-lobed; aril orange to blood-red, sometimes split and exposing the seed.

E. hamiltonianus is a taxonomically difficult group, in need of detailed study. It does not subdivide neatly, but plants from the north-eastern corner of its range are distinct in their slender leaves (see var. maackii). Plants from Japan, S. Korea, and Sakhalin have been separated from E. hamiltonianus as E. sieboldianus, but all the characters given by Rehder to distinguish this species can be found in Himalayan plants. Komarov placed E. sieboldianus under E. hamiltonianus as a variety and gave as the difference that in var. sieboldianus the flowers are heterostylous: those with long styles have stamens with short filaments and vice versa, whereas in typical E. hamiltonianus the tendency is for flowers with long styles to have long filaments and vice versa (C. Jeffrey, Bot. Mag., n.s., t. 548). It is possible that there are also statistical differences in size and shape of leaves and fruits, etc. The Japanese plants, like those of China and the Himalaya, are variable, and Koehne’s three “species” – E. yedoensis, E. semiexsertus, and E. hians – represent slightly differing forms and were described from cultivated plants. See further below, under var. sieboldianus.

Typical E. hamiltonianus is represented in cultivation by plants known by the synonymous name E. lanceifolius; these were probably all raised from Wilson’s No. 1105, collected in W.China during his expedition for the Arnold Arboretum. They are semi-evergreen, vigorous large shrubs or small trees up to 30 ft high, but do not fruit freely. Wilson also sent seeds from W. China when collecting for Veitch (W. 1202), and the material figured in Bot. Mag., n.s., t. 181, came from a plant at Kew raised from this number.

From the Supplement (Vol. V)

var. sieboldianus – This is given the rank of a subspecies of E. hamiltonianus by Dr Hara, distinguished by its larger fruits 7 to 10 mm long and 7 to 13 mm wide, shallowly depressed in the centre, against 5 to 8 mm by 7 to 10 mm in the typical state of the species, and the larger seeds.

The status of Chinese members of the complex is uncertain. But the Wilson introductions from Hupeh and western Szechwan, identified as E. lanceifolius in Plantae Wilsonianae, belong almost certainly to var. sieboldianus. As for E. lanceifolius itself, described by Loesener from a specimen collected by Henry in south-east Yunnan, this is certainly not a distinct species. It belongs to E. hamiltonianus sens. lat., and agrees with var. sieboldianus in having larger fruits than in typical E. hamiltonianus. Relative width of leaf is not in itself of any significance in this complex, since narrow-leaved forms occur throughout the range of the species, including Japan.


var. maackii (Rupr.) Komar.

Synonyms
E. maackii Rupr.
E. europaea var. maackii (Rupr.) Reg

Leaves narrow-elliptic to lanceolate, mostly 2{1/4} to 4 in. long, {3/4} to 1 in. wide (smaller on the flowering twigs), tapered at both ends, the apex acute, acuminate or even caudate, dark green above, paler beneath, edged with fine incurved teeth; leaf-stalk {1/4} to {3/4} in. long. Flowers and fruits as in typical E. hamiltonianus, but the inflorescences are perhaps fewer-flowered on the average. Native of the Russian Far East, Korea, and N.E. China; described (as a species) in 1857 from specimens collected by Richard Maack on the Amur River; introduced to Kew before 1880.

var. sieboldianus (Bl.) Komar.

Synonyms
E. sieboldianus Bl.
E. hamiltonianus subsp. sieboldianus (Bl.) Hara
E. yedoensis Koehne
E. hians Koehne
E. semiexsertus Koehne
E. nikoensis Nakai
varieties based by Blakelock on the preceding four species
E. vidalii Fr. & Sav

This variety is mainly represented in gardens by the plants called “E. yedoensis”, with obovate or elliptic leaves up to 5 in. long and 3 in. wide, pink capsules and seeds with an orange almost closed aril. Plants were in commerce under this name before Koehne formally described the “species” in 1904, and are believed to have been introduced from Japan by the American nurseryman Parsons about 1865. In autumn the leaves turn to various shades of rose and red and make a lovely combination with the pink fruits. But the autumn colour varies, either because it depends on soil and situation, or because there is more than one clone in the trade. Another form of the Japanese spindle-tree was named E. semiexsertus by Koehne. In this the aril is open on one side, exposing the true seed-coat.