Whether you've been looking for it or not, you likely come across wild fennel, or Foeniculum vulgare, quite frequently. On a recent sample gathering in West Oakland, I was once again struck by just how rampantly wild fennel grows. Asphalt, cement, roadsides, or parking lots, wild fennel survives and thrives everywhere.
A member of the same family as carrot, parsley, and dill, fennel has thin feathery leaves that connect to a larger stem. The plants can grow very tall and may have delicate yellow flowers. On foraging walks, I always get very hopefully asked about how to harvest the fennel bulb, but alas, wild fennel does not have a large bulb as you find with conventional fennel. Fortunately, the leaves are incredibly abundant and flavorful, as are the stalks, and flowers, pollen, and seeds in season. Fennel often grows alongside poison hemlock, which is in the same family, but has leaves more like carrot tops and purple splotches on the stems. If you are unsure if what you have is fennel, give it a smell - the smell will undeniably tell you if you have fennel. You can find fennel primarily in the spring through early fall, though I have seen it at all times of the year, and the flowers and pollen can be found in the summer.
Although you probably wouldn't want to make an entire salad of fennel, the sweet anise and licorice flavor works great as a garnish. Try it in sauces, on fish or chicken, in omelettes, desserts, and as a salad component. The pollen is lovely as a tasty condiment and the seeds are a digestive aid.
The below is NOT FENNEL, but POISON HEMLOCK. Note the carrot-like leafy tops and purple splotches on the stem. The poison hemlock flowers are similar to fennel so be sure you carefully determine what you're picking and identify the fennel by the feathery, thin leaves and smell.