Sycamore Trees (or Plane Trees) are large trees in the Platanus genus of the Plane Tree family, typically deciduous and often found in wetlands. There are about 25–30 species in this genus, but only one is native to Woodland. Additionally, one non-native species is sometimes planted by the city of Woodland.
Sycamore trees are a major cause of hay fever. They typically bloom from about February through May, so if you suffer from hay fever during those months, sycamore trees could be the culprits.
Western Sycamore (Platanus racemosa) is a fast-growing deciduous tree native to most of Woodland, all of Davis, all of West Sacramento, and all of the rural areas in between them, as well as to the Dunnigan Hills. With a lifespan of about 400 years, it can grow to over 100 feet tall but more often stays under 80 feet tall. Often multitrunked, it has yellow and orange fall color and peeling bark that reveals paler layers of bark underneath, with white bark as the lowest layer. It prefers full sun and often grows in canyons, floodplains, or streamside habitats. With sufficient irrigation, it can grow 30 feet or more in five years. Giving it plenty of water also has the effect of causing its roots to grow downward rather than outward, making it a safe tree to plant next to sidewalks, driveways, or patios. Male and female flowers are borne on the same tree. Western Sycamore is ranked 9 out of 10 on the Ogren Plant Allergy Scale, indicating a tendency to cause severe hay fever. The City of Woodland says there are Western Sycamore trees planted in Campbell Park, Dick Klenhard Ballfield Complex, Pioneer Park, Ralph Harris Park, Rick Gonzales, Sr., Park, Wayne Cline Park, and William Crawford, Sr., Park. Additionally, Western Sycamores are said to be planted as street trees on 3rd Street, 4th Street, County Road 102, East Gum Avenue, East Main Street, Elm Street, Grand Avenue, Kentucky Avenue, Marshall Avenue, and North College Street. However, it's very likely that all of these supposed Western Sycamores are actually hybrids with some London Plane ancestry, because most Western Sycamores younger than 200 years old are not pure Western Sycamores.
London Plane (Platanus × hispanica) is a deciduous tree believed to be a hybrid of Oriental Plane (Platanus orientalis), which is from eastern Europe through central Asia, and American Sycamore (Platanus occidentalis), which is from eastern and central North America. It usually grows about 65 to 100 feet tall. Male and female flowers are borne on the same tree. Western London Plane is ranked 9 out of 10 on the Ogren Plant Allergy Scale, indicating a tendency to cause severe hay fever. Additionally, the seeds and young leaves shed tiny, stiff hairs that are often inhaled and can exacerbate breathing difficulties for people with asthma. There are London Plane trees planted in Campbell Park, Christiansen Park, City Hall, City Park, Dave Douglass Park, Dick Klenhard Ballfield Complex, Everman Park, Freeman Park, Grace Hiddleson Park, Jack Slaven Park, John Ferns Park, Ralph Harris Park, Rick Gonzales, Sr., Park, Wayne Cline Park, William Crawford, Sr., Park, Woodland City Cemetery, and Woodland Sports Park. Additionally, London Planes are planted as street trees on 1st Street, 2nd Street, 3rd Street, 4th Street, 5th Street, 6th Street, Bartlett Avenue, Beamer Street, Bliss Avenue, Bush Street, Carnegie Way, Cleveland Street, Clover Street, College Street, County Road 102, Court Street, Cross Street, Depot Street, East Gibson Road, East Gum Avenue, East Keystone Avenue, East Main Street, East Street, Elliot Street, Elm Street, Gum Avenue, Jackson Street, Johnston Street, Laurel Street, Locust Street, Marshall Avenue, North College Street, North East Street, North Street, Oak Avenue, Palm Avenue, Pendegast Street, Pershing Avenue, Pioneer Avenue, Sutter Street, Walnut Street, West Keystone Avenue, and Woodland Avenue, as well as on the roundabout facing Beamer Circle Park.
In fact, the Urban Forest Resource Analysis published by the City of Woodland in 2018 indicated that London Planes were the single most prevalent tree species in Woodland's city-maintained urban tree canopy, with 1,458 London Plane trees comprising 10.3% of all public, city-maintained trees in Woodland. This report declared that "Woodland relies most on two species"—London Plane and Chinese Pistache trees—for good reason: "These species dominate the inventory, providing significant benefits and a sense of place. They are key to sustaining the benefits provided by the public tree resource, as well as preserving the essence of Woodland for years to come."
But how could two species that are both imported from faraway places possibly provide the best "sense of place" or "essence of Woodland"? Why are non-native trees from far away so heavily favored over trees that are native to California, perhaps even native to Yolo County, or even native to Woodland itself?
The ubiquity of London Plane Trees has made them a serious threat to our native wild Western Sycamores, as the two species have hybridized to the point that it is now quite challenging to locate any true Western Sycamores anymore. Only the oldest living Western Sycamores, which date back to before London Plane Trees had been widely planted in California yet, stand much chance now of being true Western Sycamores without any London Plane ancestry, Woodland is in the native territory of Western Sycamore trees, so by planting 1,458 London Plane trees all throughout Woodland, the municipal government of Woodland is contributing to the rapid extinction of the true Western Sycamores.