Atlantic White Cedar
A coniferous evergreen, the white cedar is so named for the pale quality of its wood. White cedar prefers lowland sites with mineral-rich soil water or upland sites with calcareous soil. Often found in transitional areas between bogs and upland hardwoods, the tree may dominate rich swamp forests, and it is these wetland areas that it primarily occupies in Maryland.
Balsam Fir
Considered one of the most important pulpwood and lumber trees in North America, the wood of a balsam is light, soft, and has a good resistance against splitting. The tree itself is an evergreen coniferous, and will grow to anywhere from 40 to 70 feet tall. Considered highly rare within Maryland, the balsam fir is actively tracked by Maryland's Wildlife and Heritage Service.
Black Ash
Also called the swamp ash or hoop ash, the black ash is a tree with porous, soft wood that belongs to the olive family. Found primarily in wet woods and swamps, these trees have been known to produce sprouts from stumps. Though not actively tracked, these trees are considered rare within the state.
Dwarf Chestnut Oak
A small deciduous tree, the dwarf chestnut oak rarely grows taller than 20 feet, and is -- as it's name suggests -- a cousin of the nearly extinct American chestnut. Known to inhabit lowlands and forest periphery, the dwarf chestnut oak is considered critically imperiled in five states, and imperiled in another five, including Maryland.