''Sabatia arkansana'', commonly known as Pelton's rose gentian, is an herbaceous annual in the gentian family. It was discovered in 2001 in several glades of the

Ouachita Mountains The Ouachita Mountains (), simply referred to as the Ouachitas, are a mountain range in western Arkansas and southeastern Oklahoma. They are formed by a thick succession of highly deformed Paleozoic strata constituting the Ouachita Fold and Thru ...

in Saline County,

Arkansas Arkansas ( ) is a landlocked state in the West South Central region of the Southern United States. It borders Missouri to the north, Tennessee and Mississippi to the east, Louisiana to the south, Texas to the southwest, and Oklahoma ...

by John Pelton, a retired mechanic turned amateur photographer and naturalist. It is known only from two locations in this county and is considered critically imperiled as a result of the presence of nearby housing developments and due to the absence of a

fire regime A fire regime is the pattern, frequency, and intensity of the bushfires and wildfires that prevail in an area over long periods of time. It is an integral part of fire ecology, and renewal for certain types of ecosystems. A fire regime describes th ...

. In summer it shows attractive rose-purple flowers.

Description

It is an

annual plant An annual plant is a plant that completes its life cycle, from germination to the production of seeds, within one growing season, and then dies. Globally, 6% of all plant species and 15% of herbaceous plants (excluding trees and shrubs) are ...

growing to about 12 cm tall. The

leaves A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, ...

are produced in opposite pairs, lanceolate, 5–15 mm long and 2–3 mm broad. The

flower Flowers, also known as blooms and blossoms, are the reproductive structures of flowering plants ( angiosperms). Typically, they are structured in four circular levels, called whorls, around the end of a stalk. These whorls include: calyx, m ...

s are about 3.5 cm diameter, with a five-lobed corolla, purplish-pink with a pale yellow center, and five yellow

stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s. The

fruit In botany, a fruit is the seed-bearing structure in flowering plants (angiosperms) that is formed from the ovary after flowering. Fruits are the means by which angiosperms disseminate their seeds. Edible fruits in particular have long propaga ...

is a capsule about 1 cm long.

Similar species

It is similar to and often occurs together with the related ''

Sabatia campestris ''Sabatia campestris'' (Texas star;United States Department of Agriculture Plants Profile''Sabatia campestris''/ref> also prairie rose-gentian, prairie sabatia, meadow pinkPlants For A Future''Sabatia campestris''/ref>) is a species of ''Sabatia' ...

''. Pelton's rose gentian differs from it in its smaller size, darker pink flowers with rounded corolla lobes and in growing on moister sites.

Taxonomy

John Pelton, an amateur nature photographer and naturalist, discovered ''Sabatia arkansana'' in 2001 northwest of the town of Owensville. Initially unaware of his discovery, he showed the plant to Theo Witsell, a botany student who was involved with the Flora of Arkansas Project, in hopes of properly identifying it. He collected specimens of it and ''Sabatia campestris'', which was also found growing at the same site. All the consulted literature seemed to suggest that both were ''S. campestris'', but the differences between the two were clear. While surveying populations of the rare pipewort ''Eriocaulon koernickianum'' in similar habitats near the town of

Bauxite Bauxite () is a sedimentary rock with a relatively high aluminium content. It is the world's main source of aluminium and gallium. Bauxite consists mostly of the aluminium minerals gibbsite (), boehmite (γ-AlO(OH)), and diaspore (α-AlO(OH) ...

, John Pringle, a botanist from the Royal Botanical Gardens in

Ontario Ontario is the southernmost Provinces and territories of Canada, province of Canada. Located in Central Canada, Ontario is the Population of Canada by province and territory, country's most populous province. As of the 2021 Canadian census, it ...

, and Witsell discovered another population of Pelton's rose gentian. After Witsell had compared his specimens with a range of specimens of ''S. campestris'' at the

Missouri Botanical Gardens The Missouri Botanical Garden is a botanical garden located at 4344 Shaw Boulevard in St. Louis, Missouri. It is also known informally as Shaw's Garden for founder and philanthropist Henry Shaw. Its herbarium, with more than 6.6 million s ...

and had confirmed that they were not the same, the plants were sent to Pringle who described and named the new species. The authors offered to name the species after Pelton, but he declined. Instead they chose the specific name ''arkansana'' due to the plant's

endemism Endemism is the state of a species being found only in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also foun ...

. Despite Pelton's refusal to have the specific epithet bear his surname, the authors suggested the common name "Pelton's rose-gentian" in his honour.

Distribution and habitat

''Sabatia arkansana'' is found exclusively in

shale Shale is a fine-grained, clastic sedimentary rock formed from mud that is a mix of flakes of Clay mineral, clay minerals (hydrous aluminium phyllosilicates, e.g., Kaolinite, kaolin, aluminium, Al2Silicon, Si2Oxygen, O5(hydroxide, OH)4) and tiny f ...

and

igneous Igneous rock ( ), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rocks are formed through the cooling and solidification of magma or lava. The magma can be derived from partial ...

glades that become wet in winter but are dry from summer through fall. Within these unique micro-habitats the plant only exists in confined flat areas along the floodplains of small streams that often dry up during the hotter months of the year. It may also be found in similar conditions near seeping springs. Due to the plant being an annual, the population numbers fluctuate every year. At the first known site, called the Womble Formation site, between 200 and over 1000 individuals were found between 2001 and 2004. The other site showed similar results. Similar habitats in the neighbouring areas of Pulaski County, Garland County and Montgomery County were searched in 2003 and 2004 in hopes of finding other sites, but none were found.

References

{{Taxonbar, from=Q7395936 arkansana Flora of Arkansas Plants described in 2005 Flora of Northern America