English Ivy vs Atlantic Ivy
These two species are extraordinarily challenging to tell apart. There are differences in leaf shape and color, but variation makes this less reliable. There are differences in trichomes as well. These species can hybridize, although hybrids are uncommon.
English Ivy (Hedera helix) | Atlantic Ivy (Hedera hibernica) |
An evergreen vine, native to Europe and western Asia; introduced in North America, and widely established. | An evergreen vine native to western Europe and introduced in North America; highly invasive in the Pacific Northwest. |
 Veins whitish, contrast more with dark green leaf. Leaves usually longer than wide. Photo © Doug Goldman, CC BY 4.0. |  Veins greenish, not as pale. Leaves usually wider than long. Photo © Doug Goldman, CC BY 4.0. |
 Trichomes (clusters of hairs on surfaces of leaves and stems) radiate outward from the leaf in all directions, leading to more fuzzy appearance and texture. Photo © Doug Goldman, CC BY 4.0. |  Trichomes tightly pressed against the leaf or stem surface. Photo © Doug Goldman, CC BY 4.0. |
References & External Resources
These short lists show only links helpful for ID. For a complete list of references and resources also covering other aspects of ecology, visit the links section of the full article on each plant, which is the first entry here.
