Kentucky glade cress (Leavenworthia exigua laciniata)
Taxonomy:
Listing Status:
Where Listed: WHEREVER FOUND
General Information
L. exigua var. laciniata is an annual member of the mustard family (Brassicaceae) known only from two counties in Kentucky. Plants are about 5 to 10 cm (1.97 to 3.94 in) in height with early leaves that are simple with a slender petiole (central stalk of the leaf) and mature leaves that are sharply lobed (appear as disconnected pieces along the main leaf vein), somewhat squarish at the ends and arranged as a rosette (circular cluster of leaves) (Evans and Hannan 1990). The flowers are small (3 to 6 mm (0.12 to 0.24 in)), white to lilac in color with four petals, green rather than lavender sepals (the outer of two floral leaves that make up the flower), and leafless stems. Leaves typically disappear by the time the plant is in fruit (Evans and Hannan 1990). The fruit is flat and pod-shaped.
- States/US Territories in which the Kentucky glade cress, Wherever found is known to or is believed to occur: Kentucky
- US Counties in which the Kentucky glade cress, Wherever found is known to or is believed to occur: View All
| Status | Date Listed | Lead Region | Where Listed |
|---|---|---|---|
| 2014-06-05 | Southeast Region (Region 4) | Wherever found |
» Federal Register Documents
» Recovery
No recovery information is available for the Kentucky glade cress.
» Critical Habitat
| Date | Citation Page | Title | Document Type | Status |
|---|---|---|---|---|
| 2014-05-06 | 79 FR 25689 25707 | Designation of Critical Habitat for Leavenworthia exigua var. laciniata (Kentucky Glade Cress) | Final Rule | Final designated |
| 2013-05-24 | 78 FR 31479 31498 | Designation of Critical Habitat for Leavenworthia exigua var. laciniata (Kentucky Glade Cress) | Proposed Rule | Not Required |
To learn more about critical habitat please see http://ecos.fws.gov/crithab
» Conservation Plans
No conservation plans have been created for Kentucky glade cress.
» Petitions
» Life History
Habitat Requirements
L. exigua var. laciniata appears to be adapted to environments with shallow soils interspersed with flat-bedded, Silurian dolomite and dolomitic limestones, which is an uncommon geological formation in Kentucky (Rollins 1963; Evans and Hannan 1990). The soil on these horizontally bedded limestone areas is often only a few inches in depth or may be completely lacking in some areas (Rollins 1963). Because of the thin soils and underlying limestones, these habitats, called cedar or limestone glades, are extremely wet from late winter to early spring and quickly become dry in May and June. The natural habitat for L. exigua var. laciniata is these cedar glades (Baskin and Baskin 1981), but the taxon is also known from overgrazed pastures, eroded shallow soil areas with exposed bedrock, and areas where the soil has been scraped off the underlying bedrock (Evans and Hannan 1990). L. exigua var. laciniata does not appear to compete well with other vegetation and is shade intolerant (Evans and Hannan 1990).
Reproductive Strategy
L. exigua var. laciniata persist through the winter as rosettes, and flowering begins in late February to early March (Baskin and Baskin 1981; Evans and Hannan 1990). Seeds are set and plants die in April and May as the glade habitats dry out (Baskin and Baskin 1985; Solbrig 1971). At maturity, most of these seeds are dormant and will not germinate following dispersal, even if the soils are moist (Baskin and Baskin 1985). During the summer, these seeds undergo physical changes known as after-ripening and move from dormancy to conditional dormancy and finally, become non-dormant for fall germination (Baskin and Baskin 1985).
» Other Resources
NatureServe Explorer Species Reports -- NatureServe Explorer is a source for authoritative conservation information on more than 50,000 plants, animals and ecological communtities of the U.S and Canada. NatureServe Explorer provides in-depth information on rare and endangered species, but includes common plants and animals too. NatureServe Explorer is a product of NatureServe in collaboration with the Natural Heritage Network.
ITIS Reports -- ITIS (the Integrated Taxonomic Information System) is a source for authoritative taxonomic information on plants, animals, fungi, and microbes of North America and the world.
FWS Digital Media Library -- The U.S. Fish and Wildlife Service's National Digital Library is a searchable collection of selected images, historical artifacts, audio clips, publications, and video.
