Alangium platanifolium Seeds | Sycamore-leaved Alangium

Sycamore-leaved alangium with maple-like lobed leaves and clusters of small pale flowers — Sycamore-leaved Alangium (*Alangium platanifolium*): Cornaceae, the lobed-leaved Asian relative of the medicinal *A. chinense*.

LATIN NAME: Alangium platanifolium

COMMON NAME: Sycamore-Leaved Alangium

Plant Profile

This is the second of the two alangiums in the trade, and it is the one with the leaves that look like a maple and turn clear yellow in autumn. It is a deciduous shrub or small tree, three to eight metres, with a slender trunk, an open crown and long-stalked leaves that are three- to five-lobed, coarsely toothed and up to twenty centimetres across, turning a clear yellow in autumn.

The flowers appear in summer in loose clusters, each with six to eight narrow white petals that curl back to expose a boss of stamens, and they are strongly and rather sweetly scented. The fruit is a small oval drupe, blue-black when ripe, hanging in clusters in autumn. The whole plant has a light, open habit that reads as delicate rather than substantial, which is why it is usually grown where the leaves can be seen close up.

Science & Biotechnology

The genus Alangium is a puzzle in plant geography. Its species are scattered from West Africa through India and China to Japan, Australia and the western Pacific, a distribution that only makes sense if the group is old and has been broken up by continental drift rather than by recent dispersal. It was long kept in its own family, Alangiaceae, and is now usually placed in an expanded Cornaceae on molecular evidence, though the debate is not entirely settled.

The two Chinese species are easy to confuse and worth separating. Alangium chinense, the source of the Chinese drug Ba Jiao Feng, has ovate, unlobed leaves and a wider range; Alangium platanifolium, this species, has the lobed, maple-like leaves and a more northerly distribution into Korea and Japan. Both contain alkaloids with muscle-relaxant activity, and both are toxic enough that the root bark is a professional medicine rather than a garden remedy.

Uses & Benefits

The Chinese name for this species is Gua Mu, and its root bark has a place in folk practice as a muscle relaxant and analgesic, used for rheumatism and traumatic injury. The margin between a therapeutic dose and a dangerous one is narrow, the plant depresses respiration at higher doses, and it should not be used without professional supervision; the ornamental value is a separate matter entirely.

In the garden it is a foliage plant for a sheltered, lime-free site in light shade, where the large lobed leaves and the scented summer flowers can be appreciated. It is uncommon in cultivation and rarely offered by nurseries, which makes it a plant for collectors and for woodland gardens with a taste for the unusual. Its autumn colour is reliable and good, and it combines well with ferns and other shade perennials.

Growing from Seed

Seed should be sown fresh or stratified cold for eight to twelve weeks. Clean the flesh from the drupes, sow in a humus-rich, lime-free mix, cover lightly and keep at about eighteen degrees in filtered light. Germination is slow and uneven, and a proportion of the seed may not appear until the second spring.

Grow the seedlings on in pots for two years, in shade rather than full sun, since the young leaves scorch easily. Plant out in autumn into deep, moist but well-drained woodland soil, and mulch with leaf mould each year. The plant is hardy in most temperate gardens once established, though late frost can damage young growth, and it prefers shelter from strong wind, which tears the large leaves.

Our Take

An uncommon woodland tree with maple-like leaves and a difficult medicinal relative; one for the collector’s shade border. Site it in shade, leave the large leaves alone, and let it settle slowly.

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