Sudbury-Assabet-Concord River Watershed

Invasives

European Alder (Alnus glutinosa (L.) Gaertn.)

European alder, also known as common alder or black alder is a tree that grows 40-50 ft in height. Its branches are alternate. Its leaves are simple, oval, 2 to 4 inches long, 2 to 3 inches wide, with a rounded or slightly notched tip, have a doubly serrate margin,…

European Rusty Willow and Gray Willow (Salix atrocinerea (L.) Gaertn.) and Gray Willow (S.cinerea (L.) Gaertn.)

European rusty willow is a tall shrub or small tree that grows up to 50 feet tall; it has smooth gray-green bark with a waxy texture and raised ridges in the wood. Gray willow is a multi-stemmed shrub that may grow up to 20 feet tall. The two willows are…

Fig Buttercup (Ficaria verna Huds.)

Fig buttercup, also called lesser celandine, is a low perennial herb that grows from tuberous roots. Most plants are no more than 6 inches tall, although some reach 1 foot. The shiny leaves are dark green, often paler on their undersides. Leaves have long petioles and may be oblong, triangular,…

Garlic Mustard (Alliaria petiolata)

Garlic mustard is a cool season biennial herb with stalked, triangular to heart-shaped, coarsely toothed leaves that give off an odor of garlic when crushed. First-year plants appear as a rosette of green leaves close to the ground. Rosettes remain green through the winter and develop into mature flowering plants…

Glossy Buckthorn (Frangula alnus)

Glossy buckthorn is a tall shrub or small tree reaching 20-25 feet in height and 10 inches in diameter. Most often it grows in a large shrub growth form, having a few to several stems from the base. The shrub has spreading, loosely-branched crowns. The leaves are thin, glossy, and…

Narrow-leaf Bittercress (Cardamine impatiens)

Narrow-leaf bittercress is an herbaceous annual or biennial plant that can reach two feet in height. When narrow-leaf bittercress occurs as a biennial, the first year’s growth is a basal rosette of leaves. In the second year, it produces a flowering stem. The basal leaves of the plant are deeply…

Water Chestnut (Trapa natans)

Water Chestnut is a rooted, aquatic plant with both floating and submersed leaves. The floating leaves form a rosette and are green, glossy and triangular with toothed edges. The submersed leaves are feathery, and are found whorled around the stem. Plant stems are cord-like and can attain lengths of up…

Wild Chervil (Anthriscus sylvestris (L.) Hoffm.)

Wild chervil, also called cow parsley, is an herbaceous biennial that grows 3–4 feet tall. The hollow stems are branched and covered with soft hairs. The compound, alternate leaves are fernlike—each leaf is divided into leaflets that are also divided. Plants have long taproots that grow up to 6 feet…