American Sycamore Platanus occidentalis Linnaeus    Synonyms: Buttonwood.
Kingdom Plantae   >   Division Tracheophyta   >   Class Magnoliopsida   >   Order Hamamelidales   >   Family Platanaceae   >   Genus Platanus   

Status:

The American Sycamore is a common tree of floodplains and rich hardwood bottomlands throughout most of Maryland. On the lower Eastern Shore American Sycamore becomes very uncommon.

Description:

On rich bottomlands, American Sycamore can reach 150 ft (46 m) in height and 12 ft (3.6 m) in diameter. No eastern hardwood can grow taller than it, except the tulip tree, and none exceeds it in girth. Sycamore can also grow in a shrubby, gnarled form on rocky river floodplains, such as the Potomac River gorge (Yanosky, 1982).

The tree can be easily identified by habitat and the mottled appearance of the bark. On the upper trunk and branches, the bark is smooth and mottled, with patches that are whitish, greenish-gray, to yellowish. The broad leaves are also distinctive along with the round seed pod that hangs from a long stalk.

American Sycamore can be confused with the London Plane Tree (Platanus xacerifolia). The London Plane Tree is a hybrid sycamore that has been planted extensively in towns and cities across the United States. One of the easiest ways to differentiate between an American Sycamore and the hybrid London Plane Tree is habitat. American Sycamore is a tree of rich riverine bottomland while the London Plane Tree is a tree of streets and yards. The other way to easily differentiate between the two is by looking at the seed pods. American Sycamore has a single seed pod per stem while the London Plane Tree has two seed pods per stem.

Where to find:

In winter, stream valleys can be traced by the zones of white-crowned American Sycamores lining them. The tree is very common along the Potomac River. The C&O Canal has many fine examples of large, magnificent American Sycamores that can be easily viewed along the towpath.

Relationships:

Host plant for various species of moth including Two-toned Ancylis Moth, Imperial Moth, Banded Tussock Moth, Sycamore Tussock Moth and American Dagger Moth. The leaves are mined by the micromoths Ectoedemia platanella and Ectoedemia clemensella.

The weevil Myrmex myrmex feeds on dead and dying twigs.

Seeds are the primary food source of Sycamore Seed Bug.

The Yellow-throated Warbler, a breeding bird in Maryland, nests "locally in tall sycamores along rivers in the northern and western parts of the state" (Robbins and Blom, 1996).

There are 727 records in the project database.

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An American Sycamore in Montgomery Co., Maryland (3/18/2017). Photo by Ashley Bradford. (MBP list)

An American Sycamore in Montgomery Co., Maryland (11/21/2012). Photo by Mike Ostrowski. (MBP list)

An American Sycamore growing in Montgomery Co., Maryland (3/18/2017). Photo by Ashley Bradford. (MBP list)

An American Sycamore in Allegany Co., Maryland (4/27/2014). Photo by Kimberly Booth. (MBP list)

American Sycamore growing in Frederick Co., Maryland (3/25/2016). Photo by Mark Etheridge. (MBP list)

A large American Sycamore hosting Carroll County's first nesting pair of Yellow-crowned Night-herons (Carroll Co., Maryland, 7/9/2016). Photo by Bill Hubick. (MBP list)

American Sycamore in Caroline Co., Maryland (10/31/2020). (c) Wayne Longbottom, some rights reserved (CC BY-NC). Photo by Wayne Longbottom. (MBP list)

American Sycamore in Montgomery Co., Maryland (9/29/2020). (c) Jane Hill, some rights reserved (CC BY-NC). American Sycamore often grows as a stately tree in rich bottomlands, but can also withstand, in stunted form, battering floods on rocky flood plains, as along this channel of the Potomac River Gorge. Photo by Jane Hill. (MBP list)

American Sycamore fruit and buds in Prince George's Co., Maryland (3/23/2019). Photo by Matthew Beziat. (MBP list)

American Sycamore growing in Kent Co., Maryland (4/1/2016). Photo by Nancy Martin. (MBP list)

American Sycamore in Washington Co., Maryland (3/11/2013). The bark at the base of older American Sycamores is typically not pealing. Photo by Jim Brighton. (MBP list)

American Sycamore in Anne Arundel Co., Maryland (2/18/2012). County Champion Sycamore, sixth largest in Maryland. Photo by Bill Harms. (MBP list)

An American Sycamore leaf in Allegany Co., Maryland (10/9/2011). Photo by Kimberly Booth. (MBP list)

American Sycamore flowers and leaves, in Anne Arundel Co., Maryland (4/19/2011). Photo by Bill Harms. (MBP list)

American Sycamore in bloom in Anne Arundel Co., Maryland (4/21/2017). Photo by Bill Hubick. (MBP list)

American Sycamore in fruit in Caroline Co., Maryland (9/4/2016). Photo by Wayne Longbottom. (MBP list)

American Sycamore fruits in Harford Co., Maryland (12/6/2015). Photo by Bill Hubick. (MBP list)

American Sycamore fruits in Frederick Co., Maryland (3/11/2018). Photo by Robert Ferraro. (MBP list)

American Sycamore in Montgomery Co., Maryland (1/28/2017). Remnant of leafy stipule surrounding twig at point where previous year's leaf was attached. Photo by Bill Hill. (MBP list)

The bud of an American Sycamore in Anne Arundel Co., Maryland (3/3/2013). Photo by Jim Brighton. (MBP list)

The bud of an American Sycamore in Anne Arundel Co., Maryland (3/3/2013). Photo by Jim Brighton. (MBP list)


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