• Double O Arch

    Arches

    National Park Utah

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  • Delicate Arch Viewpoint Inaccessible

    Wolfe Ranch and the hiking trail to Delicate Arch are open, but flood waters and mud have blocked the road to Delicate Arch Viewpoint.

  • Safety in Bear Country

    Black bears have been seen near Devils Garden Campground. Don't lure or feed them. Dispose of trash in designated receptacles; don't leave it in bags or other soft containers. Store food in vehicles or hard containers when not being prepared or consumed. More »

Poison Ivy

Toxicodendron rydbergii

Toxicodendron rydbergii

Family: Anacardiaceae – Cashew Family

Dioecious shrubs; 3.9” to 11.8” (1 to 3 dm) tall or more

Leaves: alternate; compound; 3 leaflets; the terminal leaflet is 0.8” to 4.4” (2 to 11 cm) long, 0.6” to 4” (1.5 to 10 cm) wide; can have hairs

Flowers: 5 whitish to yellowish petals with dark veins, 0.08” to 0.12” (2 to 3 mm) long; 5 sepals; stamens usually 5 or 10; flowers are dioecious (individual flowers are either male or female, but only one sex is to be found on any one plant)

Pollinators: other genera in this family are pollinated by insects (specifically bees)

Fruits: cream to yellow drupes

Blooms in Arches National Park: May, June

Habitat in Arches National Park: riparian communities

Location seen: Fiery Furnace, outside Arches National Park in Negro Bill Canyon

Other: The genus name, “Toxicodendron”, means “poison tree” and the species name, “rydbergii”, honors Per Axel Rydberg (1860-1931), a plant taxonomist and the first curator of The New York Botanical Garden Herbarium whose specialty was the flora of the Rocky Mountains and Great Plains areas.

Caution: Rubbing against this plant can produce severe dermatitis in sensitive people. All the parts, including smoke from fires containing it, should be avoided by everyone.

Did You Know?

Common Raven

The common raven displays abilities to play and problem-solve that are rare among animals. This member of the crow family is also very vocal, communicating with over a dozen sounds. Perhaps because of these qualities, ravens have achieved a certain stature in both European and Native American folklore.