Umbellularia californica is a large tree native to coastal forests of California and slightly extended into Oregon.
It is the sole species in the genus Umbellularia.
Its pungent leaves have a similar flavor to bay leaves (though stronger), and it may be mistaken for Bay Laurel.
In Oregon, this tree is known as Oregon Myrtle, while in California it is called California Bay Laurel, which may be shortened to California Bay or California Laurel. It has also been called Pepperwood, Spicebush, Cinnamon Bush, Peppernut Tree and Headache Tree.
It ranges near the coast from Douglas County, Oregon south through California to San Diego County. It is also found in the western foothills of the Sierra Nevada mountains. It occurs at altitudes from sea level up to 1600 m.
It is an evergreen tree growing to 30 m tall (exceptionally 45 m) with a trunk up to 80 cm thick.
The fragrant leaves are smooth-edged and lens shaped, 3–10 cm long and 1.5–3 cm broad, similar to the related Bay Laurel though usually narrower, and without the crinkled margin of that species.
Flowers open in late winter and early spring.The flowers are small, yellow or yellowish-green, produced in a small umbel (hence the scientific name Umbellularia, "little umbel").
The fruit, also known as "California Bay nut", is a round and green berry 2–2.5 cm long and 2 cm broad, lightly spotted with yellow, maturing purple. Under the thin, leathery skin, it consists of an oily, fleshy covering over a single hard, thin-shelled pit, and resembles a miniature avocado. Genus Umbellularia is in fact closely related to the avocado's genus Persea, within the Lauraceae family. The fruit ripens around October-November in the native range.
The California Bay is the primary foliar host for Sudden Oak Death (SOD).
Umbellularia has long been valued for its many uses by Native Americans throughout the tree's range, including the Cahuilla, Chumash, Pomo, Miwok, Yuki, Coos and Salinan people.
The leaf has been used as a cure for headache, toothache, and earache—though the volatile oils in the leaves may also cause headaches when used in excess. Poultices of Umbellularia leaves were used to treat rheumatism and neuralgias. Laurel leaf tea was made to treat stomach aches, colds, sore throats, and to clear up mucus in the lungs. The leaves were steeped in hot water to make an infusion that was used to wash sores. The Pomo and Yuki tribes of Mendocino County treated headaches by placing a single leaf in the nostril or bathing the head with a laurel leaf infusion.
Both the flesh and the inner kernel of the fruit have been used as food by Native Americans. The fatty outer flesh of the fruit, or mesocarp, is palatable raw for only a brief time when ripe; prior to this the volatile aromatic oils are too strong, and afterwards the flesh quickly becomes bruised, like that of an overripe avocado. Native Americans dried the fruits in the sun and ate only the lower third of the dried mesocarp, which is less pungent.
The hard inner seed underneath the fleshy mesocarp, like the pit of an avocado, cleaves readily in two when its thin shell is cracked. The pit itself was traditionally roasted to a dark chocolate-brown color, removing much of the pungency and leaving a spicy flavor Roasted, shelled "bay nuts" were eaten whole, or ground into powder and prepared as a drink which resembles unsweetened chocolate. The flavor has been described variously as "roast coffee," "burnt popcorn" or "dark chocolate". The powder might also be pressed into cakes and dried for winter storage, or used in cooking. It has been speculated that the nuts of U. californica contain a stimulant; however this possible effect has been little documented by biologists.