Wednesday, August 11, 2010



A genus of only 2 species of plants that are shrubs native to North America

Dirca palustris ( Leatherwood )
A slow growing, deciduous shrub native to eastern North America ( from far northeast North Dakota to Thunder Bay, Ontario to Sault Ste Marie to Manitoulin Island to North Bay, Ontario to Mattawa, Ontario to southern Quebec to Nova Scotia; south to eastern Oklahoma to far northwest Florida to central South Carolina ). It is endangered in North Dakota, Oklahoma, Louisiana, Mississippi, Florida, Georgia, South Carolina, North Carolina, Maryland, Delaware and New Jersey. It is very common on the Bruce Peninsula and Manitoulin Island in Ontario. In the Windsor/Essex County, Ontario region; it was locally abundant in the Colchester area during the 1800s. It was once abundant along the Vermillion River on the Ohio shore but had already declined considerably there by the late 1800s. Leatherwood can reach up to 7 feet in height though the largest on record in much larger at 11 x 12 feet with a trunk diameter of 5 inches. It is usually found in moist, upland, deciduous or mixed woodland.
The foliage appears very early in spring and is luxuriant mid-green, turning to golden-yellow during autumn. The alternately-arranged, leathery, smooth-edged, oval leaves are up to 5 x 3 inches in size.
The flowers are borne in axilliary clusters before the foliage during early spring.
The fruits are an oval drupe up to 0.5 inches in length containing a single seed. They appear during early summer. The fruit is known to have a narcotic effect.
The tough, flexible branches are yellowish and the bark is gray, tough, leathery and fibrous. All parts of the plant are poisonous and can cause skin irritation.
Hardy zones 3 to 8 ( possibly 2 for most northern seed source ) in sun or shade but are definately of better form in sun. The Leatherwood does prefer moist, well drained soil. Shape young plants to a single trunk up to 12 inches in height to prevent ice damage. Branches split easily due to narrow crotches. Stumps do not resprout. Propagation is from seed sown immediately upon ripening or from layering.

* photos taken on August 3 2010 @ University of Guelph Arboretum, Ontario

* photo taken @ U.S. Botanical Garden, Wash., DC on Aug 25 2014

* photos taken on Jul 18 2017 @ Dominion Arboretum, Ottawa, ON

Dirca occidentalis ( Western Leatherwood )
The western counterpart to Dirca palustris is a rare shrub native to moist wooded sites in the San Francisco Bay area of California only. It is very similar but the fruits are red.
Hardy zones 6 to 8

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