You know those moments where you think you know something–until suddenly you realize you don’t? Well this happened to me recently with periwinkle. I’ve seen this shrubby, large-flowered vine my entire life, but it wasn’t until I went to key it out that I realized I didn’t know its name. And when I finally came to periwinkle I couldn’t have been more surprised. This familiar plant is periwinkle? The periwinkle of literature, of blues and eyes and dresses? I always thought it would be some delicate British daisy; instead, it’s this coarse and common invasive!
The bigleaf periwinkle of real life is Vinca major, a dark-leaved vine with a milky, sticky sap. This invasive ground cover escaped from garden plantings and now is creeping across the U.S. In California you can see it in coastal areas, foothill woodlands, the Central Valley, and even in the desert. It forms dense mats, crowding out natives, and can resprout from bits of broken stem or root–a particular problem because it likes to grow on stream banks, where it regularly gets washed away in high water, taking root wherever the broken piece lands.
Oaks are generally thought of as tall, graceful trees. But you can also find them in the sea of waist-high bushes known as chaparral. Leather oak (Quercus durata var. durata) is a common sight on serpentine soils in this area.
Leather oak can grow to around nine feet tall, but I have mainly noticed them growing much closer to the ground. Look close to spot acorns or clusters of catkin-like flowers among the small, grayish green leaves. The leaves of this species are dull, dusted with a pale fuzz (paler on the top than on the bottom). They also are concavely curled towards the ground–you could flip one over and use it for a little spoon, if they didn’t have a tendency to be spiny.
As with all acorns, the nut of the leather oak is edible once its bitter tannins have been leached out. Acorns were historically a major food source for local Native American tribes, and still are a major part of the food chain for wildlife. People generally remove tannins by soaking the nut in water (or a running stream). But some tribes would plant the acorn in a bog and wait until it sprouted in the spring–a system which apparently got rid of most tannins but preserved more nutrients than the water method.
Acorns can be eaten whole, or ground into a floury powder for cooking. Roasted acorns can be used as a coffee substitute.