Atwood's Camissonia
Chylismia atwoodii
NatureServe conservation status
Global (G-rank): G2?
State (S-rank): S2?
Utah Wildlife Action Plan status
- SGCN
External links
General information
Atwood's camissonia, Chylismia atwoodii belongs to the Evening Primrose Family. It is endemic to the Last Chance drainage of Kane County and Tropic Shale Formations, and salt desert shrub communities. Blooming only in the months of September to October, you can find its 7-14 mm long purple flower petals as well as its fruits that range between 12-25 mm long, but only at an elevation of 1237 to 1524 meters.
Description
C. atwoodii is an annual forb with a spindly, branched stem from 0.5 up to 1.5 meters in height covered with hairs bearing glands on their tips. Leaves are petiolate, 1.2-7.5 cm long and 0.8-5 cm wide, are basal are reduced in size up the stem, and are ovate to lanceolate in shape with leaf margins ranging from minutely serrate to serrate-dentate. Flowers grow numerous in panicles. Sepals are reflexed,and flowers bear 4 lavender petals with purple spots, 8-14 mm long. C. atwoodii produces fruit capsules 11-20 mm long on pedicels.
Phenology
C. atwoodii has an annual growth cycle flowering in late summer and early autumn given adequate and timely precipitation. Welsh et al. (2015) notes it may also grow as a winter annual, germinating in the fall and living through the winter to seed the following season.
Diagnostic characteristics
Atwood’s Camissonia is unique for late summer blooms and the lavender coloration of its flower. It also has a very limited geographic distribution, endemic to eastern Kane County.
Species range
C. atwoodii is endemic to eastern Kane County, UT, where it grows at the southern margin of the Kaiparowits Plateau. This species is distributed across a range spanning approximately 700 km2, though within this range it only occupies a handful of sites estimated to total 128 km2. Within this limited range, it can be abundant in some years.
Habitat
This species is associated with salt desert shrub communities within clay soils of the Trophic Shale and overlying Straight Cliffs stratigraphic units, as well as the Chinle and Caramel geologic formations. Found at elevations of approximately 3,800-5,000 ft. Its main habitat is talus slopes, particularly talus of the Straight Cliffs that has been “clinkered;” that is, sedimentary rock that has been fused together through the natural burning of coal seams.
Threats or limiting factors
Threats to this species are not well documented but historically have included natural resource extraction and associated roads and recreational vehicles. Grazing may also be a threat. Although this species has not been evaluated for its sensitivity to increased drought and heat; many rare plant species across North America are facing impacts of extended drought and heat, regardless of geographic region. Vulnerability to these stressors is especially concerning in cases where a species is geographically restricted and/or genetically bottlenecked, as is commonly the case with rare plant species; these traits may negatively affect any individual species’ ability to adapt.
Taxonomy
No, this species does not have taxonomic discrepancies