The oak tree is a member of the Fagaceae or beech family, whose Latin root means "to eat." This likely refers to the oak tree's acorns, which are classified as edible fruit. There are different species of black oak trees throughout North America, and they share a common characteristic in terms of their flowers, which are unisexual.
In black oak trees as a whole, both the male and the female flowers appear on the same tree. The male flowers that emerge on spikes exhibit between 4 and 40 clustered stamens. The female flowers produce the eventual acorns from bracts that surround the pistil. The flowers usually appear with leaves around April or May. They are not showy flowers, having no petals, and looking insignificantly small.
The California black oak derives its botanical name, Quercus kelloggii, from Albert Kellogg, a California botanist. Although the discovery of this species took place in Sonoma, Calif. in 1846, it received its botanical name officially in 1857. It is also known as Kellogg's oak. Generally, the California black oak tree flowers between mid-March and mid-May, with trees near the coast and at lower levels exhibiting the earliest blooms.
Eastern Black Oak
The eastern black oak (Quercus velutina) is a member of the red oak (Quercus rubra) group of oak trees (Quercus sect. Lobatae). It is indigenous to eastern North America. Today it is prevalent in northern Florida, southern Maine and northeast Texas. Its other names include yellow oak, yellowbark oak, quercitron and smoothbark oak. From the leaf axils of the preceding year emerge new male or staminate flowers, around April or May. The female or pistillate flowers grow from the axils of the current year's leaves.
A North American native, the blackjack oak (Quercus marilandica) is less common than other black oaks. Its presence is often linked with ground clearing or with forest fires, which lead to its appearance on the scene. The blackjack oak tree also features monoecious floral characteristics. Its staminate flowers are usually between 2 and 4 inches in length, taking the form of hanging catkins. The small, pistillate flowers usually grow individually or in pairs.
Yellow catkin flowering denotes the black oak in Texas, a small- to medium-size evergreen tree that is in bloom during the spring. It has a variety of common names, including emory oak, holly oak, Apache oak, desert live oak, western black oak, bellota and roble negro. They all come under the botanical umbrella of Quercus emoryi. The emory oak grows in west Texas, usually at elevations of 4,500 feet and above.