Walking into Mount Pisgah Arboretum you are greeted by the iconic Oregon white oak—it is the logo of the arboretum. Spring is here and the oaks are flowering. The male and female flowers are on separate inflorescences on the same tree. Let’s take a look.

We all know acorns, and I will often hear children refer to oak trees as acorn trees. That said, I imagine that most people are not as familiar with the female flower that gives rise to this nutritious nut. It is tiny and can be easily overlooked. They grow from the axils (where the leaf stalk meets the stem) of the new leaves. The Washington State Native Plant Society describes the flowers as flollows: “The pistillate flowers grow singly or clustered. Each pistillate flower is surrounded by a scaly, cup-like involucre, contains an inferior ovary and 3 styles.” Next to the female flowers is a red-tipped structure that is growing up from the base. There is only one, even if it is a pair or a cluster of three flowers. In my research, I didn’t find any mention of what this is. For now, I am waiting and watching as it continues to grow.

The male flowers aren’t as subtle as the female flowers but they do blend into the spring green that is sprouting throughout the landscape. The male flowers are a yellowish green and hang on a thin catkin. The catkin emerges from the tree fairly compact. As it elongates the clusters of stamens spread out, open to release their pollen, and look wispy and light as they blow in the wind.

This beautiful, mighty tree is vital to creating a diverse ecosystem and produces nutritious acorns which are a food source for many animals. When the acorns are ripe, jays can be seen carrying them off in every direction to cache them for the winter.

Nature is an inexhaustible source of wonder. I look forward to seeing you out there.

See more of Bryan’s work here.


Quercus Garryana Var. Garryanahttps://www.wnps.org/native-plant-directory/232-quercus-garryana-var-garryana. Accessed 15 Apr. 2024.