Euonymus fortunei (Turcz.) Hand.-Mazz.

Wintercreeper

Euonymus_fortunei_plant.jpg
STATS

Introduced
CC = *
CW = 5
MOC = 21

© SRTurner

Family - Celastraceae

Habit - Perennial lianas, rarely appearing as mounding shrubs.

Stem - Spreading, trailing, or climbing, to 15 m or more, dimorphic, the spreading/ trailing phase exclusively vegetative, relatively slender, rooting at nodes, the climbing phase vegetative and often also reproductive, slender to more commonly relatively stout, adhering to the substrate by adventitious roots produced at and between nodes. Twigs green to grayish brown, circular in cross-section (but the older climbing stems often somewhat flattened or bluntly 3-angled).

Euonymus_fortunei_stem.jpg Stem and node.

© SRTurner

Leaves - Opposite, simple, petiolate, thick and leathery, evergreen, short-petiolate, the petiole 5-10 mm long. Leaf blades dimorphic, those of the spreading, trailing phase 1-6 cm long, 0.5-3.0 cm wide, lanceolate to elliptic or ovate, angled or tapered at the base, angled or tapered to a bluntly or sharply pointed tip, the margins finely and bluntly to less commonly sharply toothed, the upper surface green to dark green, often with pale mottling along the main veins, the undersurface lighter green; those of the climbing, fertile phase changing to somewhat more herbaceous, 4-9 cm long, 2-5 cm wide, elliptic to broadly obovate-elliptic, tapered at the base, tapered to a usually sharply pointed tip, the margins finely and usually sharply toothed, the upper surface green to yellowish green and only occasionally slightly lighter along the main veins, the undersurface light green.

Euonymus_fortunei_leaves1.jpg Stem and leaves.

© SRTurner

Euonymus_fortunei_leaf1.jpg Leaf adaxial.

© SRTurner

Euonymus_fortunei_leaf2.jpg Leaf abaxial.

© SRTurner

Inflorescences - Small axillary panicles of 5-15 flowers.

Euonymus_fortunei_inflorescence.jpg Inflorescence.

© SRTurner

Flowers - Usually perfect. Sepals 4, 1.0-1.5 mm long. Petals 4, 3-4 mm long, 2-3 mm wide, nearly circular, white to pale greenish yellow, the margins usually entire. Stamens 4, these inserted along the margin of the nectar disc. Ovary usually with 1-5 locules and 2-6 ovules per locule. Style short, stout, the stigma entire or shallowly 3-lobed.

Euonymus_fortunei_flower.jpg Flower.

© SRTurner

Euonymus_fortunei_sepals.jpg Sepals (poorly visible).

© SRTurner

Fruits - Capsules 6-8 mm long, 2-4-lobed nearly their entire length, the valves smooth, straw-colored or occasionally slightly pinkish-tinged. Seeds 1-4 per locule, 4-6 mm long, enclosed in a fleshy red aril.

Euonymus_fortunei_fruits.jpg Fruits.

© SRTurner

Flowering - June - August.

Habitat - Bottomland and mesic forests, streambanks, gardens, fencerows, railroads, roadsides, disturbed areas.

Origin - Native to Asia.

Lookalikes - Mitchella repens, Vinca spp. Fruits resemble those of Celastrus spp.

Other info. - In a list of the most noxious and invasive weeds of east-central Missouri, this species would probably occupy one of the top five slots. It probably occurs statewide (and is likely to be vastly underrepresented in collection records). It invades mesic and bottomland forests with a carpet of vines, choking out native growth. It climbs trees, smothering and breaking limbs with the weight of its growth. Its waxy leaves are impervious to many common herbicides. Once established it is impossible to eradicate. This species should never be planted deliberately.

The plant is relatively easy to identify by its leaves, which are opposite, deep green, leathery, shiny, and toothed. However, lookalikes do exist. Both Mitchella repens and Vinca spp. may be differentiated by their leaves, which have entire margins. Their flowers are also much different.

This plant exhibits a confusing variety of growth forms and leaf characters. The vegetative phase is a creeping shrub with relatively small, dark green leaves. Old plants sometimes produce ascending branches that can take on a moundlike habit. When encountering a vertical surface such as a fence, house, tree, or telephone pole, the plant climbs upward, adhering to the substrate by means of adventitious roots, and alters its morphology. The reproductive phase has stouter branches and larger, lighter green leaves. Wintercreeper is, unfortunately, widely available horticulturally. It is used primarily as an evergreen ground cover, especially in areas where dense shade or dry soil prevent landowners from growing most other species. The brightly arillate seeds are attractive to birds and sometimes also are eaten by small mammals. The characters that make this species desirable for cultivation - fast, aggressive, dense growth; evergreen leaves; and wide climatic tolerance - also make it a potentially devastating weed, growing so densely as to choke out most other species.

Synonyms for this species include E. hederaceus and Elaeodendron fortunei.

Photographs taken near Allenton Access, St. Louis County, MO, 7-31-2013, along the Katy Trail near Augusta, St. Charles County, MO, 11-6-2017, and near Labadie, Franklin County, MO, 7-20-2020 (SRTurner).