As in Celastrus, the seed is enclosed in a colorful aril (red or orange); the color of the capsule is pink, or red to purple in our species.
1. Leaves evergreen, pale along the principal veins (in the commonly collected juvenile form which is trailing or climbs by aerial roots); young branches and leaf midrib above papillose or warty.
1. Leaves deciduous, not pale along the veins; plant trailing or an erect shrub; young branches and leaf midrib not papillose or warty (branches becoming winged in E. alatus).
2. Plant a trailing, creeping shrub with erect or ascending flowering shoots; flowers 5-merous; fruit shallowly 3-lobed, strongly tuberculate, pink to red when ripe; leaf blades glabrous beneath (except sometimes on principal veins), usually obtuse.
2. Plant an erect bushy shrub or small tree; flowers 4-merous; fruit distinctly 4-lobed but nearly or quite smooth, red to purple when ripe; leaf blades pubescent or glabrous beneath, acute to short-acuminate.
3. Leaf blades finely pubescent over entire lower surface; petals dark purple, usually numerous in inflorescence; native species of rich forests.
3. Leaf blades glabrous beneath; petals yellow-green; uncommon escape along roadsides, fencerows and in disturbed forests and thickets.
4. Leaves with petioles 1.5–3.5 mm long; branches often with broad corky wings.
4. Leaves with petioles 4–22 mm long; branches with corky wings absent or narrow.
5. Larger leaves with blades 5–8 (–10) cm long (only ca. 3-7 cm when plants are in bloom); anthers yellow.
5. Larger leaves with blades ca. 11–15 cm long (as short as 9 cm when plants are in bloom); anthers purple.