Penland Alpine Fen Mustard

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Penland Alpine Fen Mustard

Eutrema penlandii

ListedJuly 28, 1993
FamilyCruciferae (Brassicaceae)
DescriptionA small, herbaceous, perennial wildflower.
HabitatAlpine wet meadows.
ThreatsMining, trampling by off-road vehicles, and other disturbances.


The alpine fen mustard is a small, herbaceous, perennial plant that grows as tall as 1.2-3.2 in (3-8 cm). Its stems and leaves are shiny-green and glabrous (hairless). It has heart-shaped basal leaves with a petiole up to 1.4 in (35 mm) long. It has clusters of small flowers, each with four white petals, atop a flowering shoot. The ripe fruits are small and rounded, about 0.06 in (1.5 mm) wide and 0.2-0.3 in (4-8 mm) long.

Some taxonomists treat the alpine fen mustard as a subspecies of Eutrema edwardsii (i.e., as E. e. penlandii ), a circumboreal plant of the Arctic of northern North America and Eurasia, extending also to the mountains of central Asia. However, other taxonomists, and the U. S. Fish and Wildlife Service, recognize the alpine fen mustard as a full species (i.e., as Eutrema penlandii ). The alpine fen mustard is isolated by more than 1,000 mi (1,600 km) from the nearest population of Eutrema edwardsii.


The alpine fen mustard occurs in alpine tundra on southerly to easterly facing slopes above 12,150 feet (3,700 m) in elevation. Its habitat is restricted to wet meadows irrigated by melting snowfields. The alpine fen mustard grows in nutrient-poor, sheltered, wet, springy, moss-covered, peaty fens. Its alpine winters may last five months or more, and summer temperatures are usually below 60°F (16°C). The growing season may only last from 0 to 70 days per year. Overall, the habitat of the alpine fen mustard is characterized by the stresses of low temperature, a short growing season, freezing, thawing soil (solifluction), drying winds, and wind-blown snow and ice crystals.


The alpine fen mustard is a local (or endemic) species that only occurs in a 25-mi (40-km) stretch of the Continental Divide in central Colorado.


The wet-meadow habitat of the alpine fen mustard is fragile and sensitive to watershed disturbances and alterations that divert flows of surface water. Direct impacts to plants and their habitat occur from mining exploration and development, trampling by off-road vehicles, and other human activities. Only five to fourteen small populations of the plant are known, containing a total of about 10,000 to 16,400 plants growing on about 500 acres (200 hectares) of alpine habitat.

Conservation and Recovery

About 80% of the known population of the alpine fen mustard occurs on federal land. This critical habitat should be strictly protected against any mining development and from direct recreational usage (by erecting fencing, if necessary). The rest of the critical habitat of the alpine fen mustard is on private land (patented mining claims), and is threatened by mining development and other disturbances. This habitat should also be protected. This could be done by acquiring the land and designating ecological reserves, or by negotiating conservation easements with the owners. The populations of the alpine fen mustard should be monitored, and studies made of its biology and habitat needs.


U. S. Fish and Wildlife Service
Regional Office, Division of Endangered Species
P. O. Box 25486
Denver Federal Center
Denver, Colorado 80225

U. S. Fish and Wildlife Service
Colorado Ecological Services Field Office
Denver Federal Center
P. O. Box 25486
Denver, Colorado 80225-0486
Telephone: (303) 275-2370
Fax: (303) 275-2371

U. S. Fish and Wildlife Service
Grand Junction Colorado River Fishery Project
764 Horizon Drive, Building B
Grand Junction, Colorado 81506-8721
Telephone: (970) 245-9319
Fax: (970) 245-6933


U. S. Fish and Wildlife Service. 28 July 1993. "Endangered and Threatened Wildlife and Plants: The Plant Eutrema penlandii (Penland Alpine Fen Mustard) Determined to be a Threatened Species." Federal Register 58 (143).