Frasera ackermaniae
| Frasera ackermaniae | |
|---|---|
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| Frasera ackermaniae in bloom | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Embryophytes |
| Clade: | Tracheophytes |
| Clade: | Spermatophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Gentianales |
| Family: | Gentianaceae |
| Genus: | Frasera |
| Species: | F. ackermaniae |
| Binomial name | |
| Frasera ackermaniae C.C.Newb. & Goodrich | |
| Synonyms | |
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Frasera ackermaniae, commonly known as Ackerman green gentian, is a rare species of flowering plant in the gentian family, Gentianaceae. It is a small perennial herb endemic to a very limited area of Uintah County, Utah, in the western United States. It is known principally from semibarren clay hillsides in the Brush Creek drainage of the Uinta Basin.[2][1]
The species was originally published under the spelling Frasera ackermanae. Its specific epithet was subsequently corrected to ackermaniae under the rules of botanical nomenclature.[1][3]
Description
[edit]Frasera ackermaniae is a perennial herb. It produces one to several shoots from a many-headed, persistent caudex attached to a long, yellowish taproot. The plant is finely puberulent, or covered with minute hairs.[2]
The basal leaves are narrowly oblanceolate. The larger basal leaves are sometimes three-veined. The leaves lack distinct petioles, are keeled, and are mostly hairless or finely puberulent near their bases. Their margins are pale or white.[2]
The stem leaves are opposite and usually occur in one or two pairs. They are narrowly oblanceolate to almost linear.[2]
The inflorescence is a compact dichasium with four to six nodes. It commonly begins among the basal leaves and constitutes approximately half, or slightly more than half, of the plant's total height. The ascending flower stalks are minutely puberulent.[2]
The flowers are four-parted. The four lance-shaped sepal lobes persist around the mature fruit. The corolla is white and flecked with blue. Its four lance-shaped lobes have a green stripe along the middle of the lower surface.[2]
Each corolla lobe bears a single oblong nectar-bearing pit, or fovea. Its rim is fringed, particularly toward the base, and the fringe hairs equal or exceed the width of the fovea. The deeply divided crown scales are white toward their tips and bluish near their bases.[2]
The fruit is a capsule. The seeds are grooved and have a wrinkled, brain-like surface.[2]
Taxonomy
[edit]Clayton C. Newberry and Sherel Goodrich formally described the species in 2010 in the journal Western North American Naturalist. Their description was based on specimens collected in 2007 from Coyote Gulch in the Brush Creek drainage of Uintah County, Utah.[2]
The name was published as:
- Frasera ackermanae C.C.Newb. & Goodrich, Western North American Naturalist 70(3): 415–417. 2010.[2]
The spelling was subsequently corrected to Frasera ackermaniae. IPNI records the corrected name as Frasera ackermaniae C.C.Newb. & Goodrich and notes that it was originally published as ackermanae.[3]
The specific epithet honors Diane Ackerman, who first noticed the plant and brought it to the attention of the authors. Ackerman had helped establish an eastern Washington chapter of the Washington Native Plant Society and later lived in Vernal, Utah.[2]
The species has also been treated as Swertia ackermanae by some authors.[1]
Similar species
[edit]Frasera ackermaniae is morphologically most similar to Frasera pahutensis, another small western North American green gentian. Both species have similar leaves, plant stature, nectar pits, and fringed floral structures.[2]
Frasera ackermaniae differs in having a more compact inflorescence, lower inflorescence nodes that often remain among the basal leaves, and longer calyx lobes. In F. pahutensis, the inflorescence is generally elevated above the basal leaves, the lower internodes are more elongated, and the calyx lobes are shorter.[2]
It also resembles the larger Frasera albomarginata, but the closest known populations of that species are approximately 300 km (190 mi) away in Emery County, Utah. The known population of F. ackermaniae is approximately 600 km (370 mi) from populations of F. pahutensis.[2]
Distribution
[edit]Frasera ackermaniae is endemic to the Brush Creek drainage in Uintah County, Utah. It occurs in the Uinta Basin and adjacent foothills of the Uinta Mountains.[1]
The total known range extent is approximately 0.6 km2 (0.23 sq mi). NatureServe recognizes one well-documented occurrence and an additional observation approximately 2 km (1.2 mi) away.[1]
At the time of its original description, the species was known only from the type locality at Coyote Gulch. There it was locally common on semibarren clay hillsides and occurred more sparingly in adjacent alluvial wash bottoms.[2]
Habitat and ecology
[edit]The species grows on yellowish clay soils containing paleosol inclusions and fragments of selenite gypsum. These soils are derived either from an unnamed upper member of the Chinle Formation or from the Bell Springs Member of the Nugget Formation.[2][1]
Plants occur at elevations of approximately 1,778–1,786 m (5,833–5,860 ft). The vegetation is a mixture of Utah juniper woodland, mountain brush, desert scrub, and sparsely vegetated barrens.[2][1]
Associated species include Amelanchier utahensis, Arenaria fendleri, Asclepias cryptoceras, Atriplex confertifolia, Caulanthus crassicaulis, Cercocarpus montanus, Cirsium calcareum, Ephedra viridis, Euphorbia brachycera, Juniperus osteosperma, Penstemon pachyphyllus, Stanleya pinnata, and Wyethia scabra.[2]
The authors of the original description suggested that low competition from other plant species may help explain the species' extremely narrow distribution. The sparse vegetation and unusual clay and gypsum substrate may limit competition while also restricting the plant to a very small habitat area.[2]
Conservation
[edit]NatureServe classifies Frasera ackermaniae as G1, or critically imperiled, globally. It is also ranked N1 in the United States and S1 in Utah. It has no status under the United States Endangered Species Act.[1]
NatureServe estimates the global population at between 2,500 and 10,000 individuals. A count conducted in 2011 estimated approximately 9,000 plants.[1]
The species has an area of occupancy of approximately 8 km2 (3.1 sq mi) under NatureServe's grid-based method. Only one occurrence is considered viable, although a second observation has been reported nearby.[1]
The principal documented threat is recreational off-road vehicle use. Dirt bikes and other all-terrain vehicles have been observed disturbing habitat within occupied areas. Because nearly the entire known population occurs at one site, even localized habitat damage could affect a substantial proportion of the species.[1]
Long-term and short-term population trends are unknown. Its extremely restricted range, concentration at a single principal site, specialized substrate, and exposure to recreational disturbance contribute to its critically imperiled rank.[1]
References
[edit]- 1 2 3 4 5 6 7 8 9 10 11 12 13 "Frasera ackermanae". NatureServe Explorer. NatureServe. Retrieved 21 July 2026.
- 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Newberry, Clayton; Goodrich, Sherel (2010). "A new species of Frasera (Gentianaceae) from Uinta Basin, Utah". Western North American Naturalist. 70 (3): 415–417. Retrieved 21 July 2026.
- 1 2 "Frasera ackermaniae C.C.Newb. & Goodrich". International Plant Names Index. Royal Botanic Gardens, Kew; Harvard University Herbaria & Libraries; Australian National Herbarium. Retrieved 21 July 2026.