The Pinnatifida or cutleaf emperor oak takes its name from the feather-like, deeply indented and lobed foliage, which emerges pinkish in the spring. Indeed, the intriguing spring foliage is the primary reason for this oak's selection. Its growth rate is often described as glacial and its mature size may be shrub-like in nature.

The genus Quercus includes more than 600 species of the oak tree, of which 90 are native to North America; the Chicago Botanic Garden's collection contains more than 60 varieties and over 1,000 individual trees. Twenty oak species are native to Illinois.

Oaks are slow growing, long lived, hard wood trees that produce fruit we all know as acorns. Within the white oak group, acorns mature annually; in the red oak group, acorns take two years to mature (biennial). Oaks are often imposing shade trees at maturity and provide habitat and food for a variety of wildlife.