Hedera helix L—English ivy
FAMILY: Araliaceae—the Ginseng Family
This family is of minor economic importance. Some noteworthy members include English Ivy (Hedera helix L.); Tetrapanax papyriferus (Hook.) C Koch, the source of Chinese rice-paper; and Panax quinquefolium L., the ginseng of Oriental medicine. Because only Hedera helix is of major concern here, a full description of this species replaces the family description.
PHENOLOGY: English ivy produces umbels of flowers in summer.
DISTRIBUTION: Hedera helix is a cultivated plant grown indoors as a pot subject or outside, usually as a wall or ground cover.
PLANT CHARACTERISTICS: English ivy is a trailing or climbing vine with a diversity of leaf shapes ranging from ovate, rotund to variously 3- to 5-lobed or angled, leaves: firm, evergreen; flowers: small, greenish, produced only when the branches reach a height of more than 15 feet; sepals: 5, very short; petals: 5, fleshy; stamens: 5; ovary: 5-celled, 1 style; fruit: a round, 3- to 5-seeded berry.
POISONOUS PARTS: The black berries and leaves of English ivy are poisonous if consumed in quantity.
SYMPTOMS: Hedera helix is a purgative that produces local irritation, excessive salivation, nausea, excitement, difficulty in breathing, severe diarrhea, thirst, and coma.
POISONOUS PRINCIPLES: The toxic substance is hederin, a glycoside of the steroidal saponin hederagenin.
CONFUSED TAXA: Several varieties of Hedera helix have 3 leaflets per leaf and resemble poison ivy (see Rhus radicans). There exist numerous foliage forms; many are not stable and, with age, revert to the original type. Generally, English ivy can be differentiated from poison ivy by its dark, glossy, evergreen foliage, compared to the thinner-textured, deciduous leaves of poison ivy.
SPECIES OF ANIMALS AFFECTED: Both humans and livestock show the symptoms listed above.
TREATMENT: (11a)(b); (17); (6)
OF INTEREST: Other species of Hedera, especially the popular Algerian ivy, H. canariensis Willd., as well as members of the genus Aralia (sarsaparilla) should be viewed with suspicion. The fruits of all species of Aralia are poisonous when eaten raw but are infrequently cooked as jelly, which is reported edible.