Rhus typhina (roos ti-fin’-a)
Family: Anacardiaceae, Cashew or Sumac

Key Steps

• 1b – Alternate leaf arrangement — go to 18
  • 18b – Leaf compound — go to 58
    • 58b – More than 3 leaflets — go to 59
      • 59c – Leaflet margins are medium-serrate — go to 64
        • 64b – Solid pith — go to 65
          • 65b – Leaflets 2-5 inches long; with leaflets increasing in size towards the leaf base. Milky sap exuding from cut stem — Staghorn Sumac

Description

Leaf: Pinnately compound, 12-24 inches long. Leaflets: 11-31, 2-5 inches long, toothed all the way around, round base, long tapered tip. Petiole is very hairy, enlarged at base to encircle bud.

Bud: Hairy, surrounded by leaf scar.

Leaf Scar: U-shaped.

Stem: Very hairy, especially on new growth. Round, over 1/2 inch thick, very small lenticels. No line encircling stem at scar.

Pith: Large, consumes most of the diameter of the stem. Brownish-yellow.

Flower: Male: yellowish-red. Female: red. On separate plants.

Fruit: Red, long, hairy spike-like, terminal upright clusters.

Habit: 15 to 20 feet tall. Open branching, resembling the horns of a male deer. Suckers.

Culture: Low moisture requirement.

Cutleaf Staghorn Sumac (Rhus typhina ‘Laciniata’) — Leaflets finely and deeply toothed.

Resources

• Identifying Broadleaf Flowering Trees and Shrubs, CMG GardenNotes #173
• List of trees in this key
• Glossary of Terms
• Front Range Tree Recommendation List
• Online CSU Extension publications on Tree and Shrub Selection