Smooth sumac is a shrub or small tree. It is common in Iowa and frequently forms thickets recognizable from a distance. Individuals are rarely over 15 ft. tall. In late summar the fruits can be seen as panicles of red drupes at the tops of the plants.
Fact Sheet (pdf), Plant Guide (pdf).
Additional pictures: 1. 2. 3.
For the genus Rhus, the USDA shows 20 species in the U.S. . Five are shown in Iowa:
R. glabra (Smooth),
R. typhina (Staghorn),
R. aromatica (Aromatic),
R.copallina (Winged), and
R. trilobata (Skunkbush).
SEE ALSO: Poison Sumac (Toxicodendron vernix)
Flowers: June; yellow; 5 petals, 5 stamen.
Fruit: drupe, in compact clusters; orange/red, short appressed hairs.
Leaves: compound; odd-pinnate, dark above, light below; stems and petioles glabrous.
Glossary: Botanical Terms pdf
Comment: In image 12 above, the structure labeled seed may be better described as the germination unit consisting of the seed and the endocarp of the fruit. As development proceeds the endocarp becomes impermeable and prevents water uptake by the embryo. The seed becomes dormant upon desiccation. Ref: Li, Baskin, and Baskin 1999. Comparative Morphology And Physiology Of Fruit And Seed Development In The Two Shrubs Rhus Aromatica And R. Glabra (Anacardiaceae) American Journal of Botany 86(9): 1217–1225.