Toxicodendron rydbergii (Small ex Rydb.) Greene

  • Family: Anacardiaceae
  • Common names: poison ivy, western poison ivy
  • Synonyms: Toxicodendron desertorum, T. radicans var. rydbergii, Rhus toxicodendron var. vulgaris, R. radicans var. rydbergii, R. radicans var. vulgaris

    Shrub to 2 m (6 ft) tall. Leaves alternate, trifoliate. Leaflets usually glabrous, variable in size and shape, to 15 cm (6 in) long, turning yellow or orange in fall. Fruits small, round yellowish pubescent drupes.

    Distribution: The species is native to most of the U. S. except the Pacific states.
    Habitat: usually near streams.
    NWI status: FAC
    Comment: The three species of Toxicodendron in Oklahoma are highly variable and difficult to distinguish. All are capable of causing a severe dermatitis, with itching and swelling of the affected parts. Toxicodendron is Greek for "poison tree"; rydbergii honors the American botanist P. A. Rydberg.

    Distribution in Oklahoma:

    Last update: 9/20/99
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