Euonymus alatus Seeds | Winged Spindle
LATIN NAME: Euonymus alatus
COMMON NAME: Winged Spindle, Winged Euonymus, Burning Bush
Plant Profile
The wings develop on the second and third year’s growth and stop there, so the oldest wood is smooth and the youngest is merely angled. Their number is the reliable character: normally four, sometimes two or three on weak shoots, running the full length of an internode. The stem beneath is green and carries out photosynthesis in winter, which is why the plant keeps working through the cold months, and the corky ridges themselves are dead tissue whose function is probably structural as much as defensive.
Plants from central and western China belong to a wingless taxon, sometimes listed as a separate variety, which grows with ordinary smooth stems and is therefore useless for winter identification. Nursery stock should be checked for the ridges while the plant is dormant. The wingless form is also generally smaller and less invasive in habit.
Flowers are small, greenish and four-petalled, carried in loose sprays on long stalks in late spring, and they are easy to overlook. The fruit is the display: a four-lobed capsule that turns pinkish red and then splits to expose bright orange arils, one seed to each lobe, hanging on the bush into autumn after the leaves have dropped. Birds take the arils and carry the seed away, and that dispersal is the mechanism behind the plant’s escape from gardens across eastern North America.
Breeders have answered with smaller, tighter cultivars. The old standard is a compact form long sold as a dwarf selection, and newer introductions have been chosen for dense habit and for producing very little fruit, which cuts the seed supply to birds. For a garden in a regulated area, those low-fruiting selections are the only sensible option, and even they are best sited away from woodland edges where birds roost.
Science & Biotechnology
The Celastraceae are chemically distinctive for dihydroagarofuran sesquiterpene polyesters, and related compounds from the family have been investigated as insect antifeedants, including wilforine from the medicinal genus Tripterygium. Material from the winged spindle itself has been screened for antioxidant flavonoids and for the alkaloid fraction, and the aril colour comes from carotenoid pigments. None of this makes the plant a crop, but it explains why the family keeps appearing in biopesticide screening programmes.
Uses & Benefits
Cork is built on suberin, a polyester of long-chain fatty acids and hydroxy acids cross-linked with aromatic monomers, laid down in the cell walls of a specialised outer layer. The wing tissue in this species is a thickened, suberised version of that layer, and its chemistry is one reason the genus has been examined for industrial waxes and cork-like materials. The bark below the wings and the leaves carry the genus’s better-known constituents: dihydroagarofuran sesquiterpene polyesters and nicotinoyl alkaloids such as evonine and euonymine, with cardenolide glycosides recorded in the European spindle.
Growing from Seed
In its native range the shrub is unremarkable; in eastern North America it is a problem. Birds move its seed into woodland, where the seedlings tolerate deep shade, and the plants layer and spread into a dense understorey that crowds out native herbs. Several northeastern states now restrict its sale or its planting, and the advice in those areas is to remove fruiting plants before the capsules colour and to replace them with native alternatives.
The seed carries an underdeveloped embryo inside a hard coat, so it needs a warm moist period to finish ripening and a cold period to break the coat, and a cold frame over two winters is the normal way to carry a batch through. Strip the arils, sow the seed in a mix of loam, leaf mould and grit, cover it to its own depth, and leave the pan outdoors. Keep the medium moist and shaded, and do not disturb the pan in the first spring if nothing appears.
Because the two requirements run in sequence, seed sown in autumn will usually show its first seedlings after the second winter rather than the first, and a pan that looks dead in its first spring is often full by the next. Prick the seedlings out into deep pots when they have two true leaves, grow them on in light shade, and plant out at about thirty centimetres. Winged spindle takes almost any soil, including clay, and colours best in full sun.
Our Take
Grow it for the winter bark and the autumn fire, and if you live where it escapes, grow one of the low-fruiting selections and pick the capsules off. The genus is full of better-behaved choices: Euonymus phellomanus carries even heavier cork, European spindle shows the same orange arils on a wilder plant, and Euonymus cornutus and Euonymus hamiltonianus cover the pink and scarlet end of the range.
Related Reading
Gardeners who grow Winged Spindle often pair it with these related subjects: