Distylium myricoides Hemsl.

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Credits

Owen Johnson (2024)

Recommended citation
Johnson, O. (2024), 'Distylium myricoides' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/distylium/distylium-myricoides/). Accessed 2024-06-20.

Common Names

  • Blue Isu Tree

Synonyms

  • Distylium myricoides var. macrocarpum C.Y. Wu
  • Distylium myricoides var. nitidum H.T. Chang

Glossary

hybrid
Plant originating from the cross-fertilisation of genetically distinct individuals (e.g. two species or two subspecies).

Credits

Owen Johnson (2024)

Recommended citation
Johnson, O. (2024), 'Distylium myricoides' from the website Trees and Shrubs Online (treesandshrubsonline.org/articles/distylium/distylium-myricoides/). Accessed 2024-06-20.

Spreading shrub or small tree; young twigs with stellate scales but lacking stellate hairs; buds with stellate hairs and Lepidoptera scales. Leaf slender, oblong or oblanceolate with a cuneate base and acute tip, usually 5–11 × 2–4 cm, blue-green above and scarcely shiny, glabrous; margin entire or with distant teeth in the upper half; petiole usually 5–8 mm long. Seed capsule ovoid, 10–12 mm long, with yellow-brown stellate pubescence; seeds 6–7 mm long. (Zhang, Zhang & Endress 2003; Dirr 2009).

Distribution  China Anhui, Fujian, Guangdong, Guangxi, E Guizhou, Hunan, Jiangxi, Sichuan, SE Yunnan (Funing Xian), Zhejiang

Habitat Evergreen mountain forests, 500–800 m asl.

USDA Hardiness Zone 7

RHS Hardiness Rating H5

Conservation status Not evaluated (NE)

The first known introduction of Distylium myricoides from China to the west may have been made by Piroche Plants of British Columbia, Canada, in 1995 (Piroche Plants 2023), while an arborescent young plant at Nymans, West Sussex, UK in 2016 was labelled as D. myricoides from L/H 124 (Tree Register 2023); this had grown 3 m tall on a single bole but had been much broken by recent snowfall.

In Athens, Georgia (North American Hardiness Zone 8a), Michael Dirr has found Distylium myricoides easy to grow and remarkably tolerant of heat, drought and full sun, although as its more southerly origins would suggest it is not quite as hardy as its more familiar relative D. racemosum, and its foliage can get temporarily browned by a cold winter (Dirr 2015). Its slender and often distinctively blue-green leaves, which can rise at regular angles all along the shoots, perhaps make this the more attractive species; in the American South, at least, the habit is denser and more graceful and spreading and the tiny reddish flowers (in late winter) are abundant.

The characteristically protean nature of distyliums can make it very hard to determine where some cultivated plants may belong, or whether they could represent garden hybrids. Jan De Langhe has observed that some plants grown as Distylium myricoides have leaves smaller than the limit suggested in the Flora of China (less than 5 cm long), with shorter leaf-stalks (less than 5 mm) and occasionally blunt leaf-tips, and he suggests that this population may include genes from D. buxifolium (De Langhe 2014; Zhang, Zhang & Endress 2003), although the first documented introduction of the latter species to the west is much more recent. One plant from Piroche Plants grown by Michael Dirr showed foliage features intermediate between D. myricoides and D. racemosum, and molecular markers show that this is of hybrid origin (Dirr 2015); plants known to derive from this stock are described here under D. myricoides × racemosum. At the Iturraran Botanic Garden in northern Spain, a plant obtained as D. myricoides from a plant sale in France shows no evidence of that species in its leaves, which are large and glossy even for D. racemosum (F. Garin pers. comm.); this plant is further discussed under D. racemosum.

Although most of the Distylium hybrids which have recently found horticultural favour can be traced back to Michael Dirr’s hybrid from Piroche Plants, a few are customarily treated as cultivars of D. myricoides. These are listed below.


'Athens Tower'

A Michael Dirr selection notable for its upright rather than gracefully spreading habit; to 2 m so far (Hatch 2021–2022). The (leaves) are dark green and particularly blunt tipped.


'Carolina Compact'

A compact selection which has been offered for sale and exchange at the Scott Arboretum of Swarthmore College, Pennsylvania (Meholic 2019).


'Lucky Charm'

Synonyms / alternative names
Distylium myricoides 'Emerald Elf'

A low and spreading form, eventually with drooping branches, with foliage typical for D. myricoides in cultivation; offered by Piroche Plants around the turn of the 21st century (Dirr 2015).


'RHL-DM1ER'

Synonyms / alternative names
Distylium myricoides BLUESCAPE™

A particularly low and dense selection with small leaves, arising in 2008 at Head’s Nursery in Georgia, from ‘Lucky Charm’ crossed with an unnamed seedling (Dirr 2022).