| Spigelia alabamensis | |
|---|---|
 | |
| Spigelia alabamensis open flower | |
 | |
| Spigelia alabmensis full plant with flower | |
Scientific classification  | |
| Kingdom: | Plantae |
| Clade: | Embryophytes |
| Clade: | Tracheophytes |
| Clade: | Spermatophytes |
| Clade: | Angiosperms |
| Clade: | Eudicots |
| Clade: | Asterids |
| Order: | Gentianales |
| Family: | Loganiaceae |
| Genus: | Spigelia |
| Species: | S. alabamensis |
| Binomial name | |
| Spigelia alabamensis (K.Gould) K.G.Mathews & Weakley | |
Spigelia alabamensis, commonly known as Alabama pinkroot, is a species of flowering plant in the family Loganiaceae. It is endemic to Alabama in the southeastern United States, where it is restricted to dolomite glades in Bibb County.[2][3]
Description
Spigelia alabamensis is a perennial herb that grows in clumps and produces tubular flowers characteristic of the genus Spigelia. It typically occurs in shallow, rocky soils and may be locally abundant in suitable habitat.[1]
Phenology
Flowering occurs from May through June.[3]
Taxonomy
The species was originally described as Spigelia gentianoides var. alabamensis by K. Gould in 1996.[3] It was later elevated to species rank as Spigelia alabamensis by K. G. Mathews and A. S. Weakley in 2011.[2]
Spigelia alabamensis is one of several narrowly endemic taxa associated with the Ketona dolomite glade system of Bibb County, Alabama.[4]
Distribution and habitat
Spigelia alabamensis is known only from Bibb County in west-central Alabama.[3][1]
It occurs in Ketona dolomite glades, a distinctive calcareous outcrop system formed on unusually pure Cambrian dolomite. Soils in these habitats are shallow, alkaline, and rich in calcium and magnesium but low in nutrients.[4]
The species grows in open glades as well as along glade margins and forest edges, and may also occur in partially shaded conditions, where flowering can be more prolific.[1]
Conservation
Spigelia alabamensis is a narrow endemic with a highly restricted range of less than 100 km2. It is ranked as G2 (globally imperiled) and S2 (imperiled within Alabama).[1]
The species is known from approximately 6–20 occurrences, with around 12 extant populations documented. Total population size is estimated at between 2,500 and 10,000 individuals, though only a portion of this has been directly surveyed.[1]
Threats include land development, livestock grazing, trash dumping, and forestry activities. Several populations occur on protected lands, including sites managed by conservation organizations, which contributes to the species' relative short-term stability.[1]
References
- "Spigelia alabamensis". NatureServe Explorer. NatureServe. Retrieved 23 March 2026.
- "Spigelia alabamensis (K.Gould) K.G.Mathews & Weakley". Plants of the World Online. Royal Botanic Gardens, Kew. 2026. Retrieved 23 March 2026.
- Weakley, Alan S. "Spigelia alabamensis". Flora of the Southeastern United States (2025 edition). North Carolina Botanical Garden. Retrieved 23 March 2026.
- Allison, James R.; Stevens, Timothy E. (2001). "Vascular flora of the Ketona dolomite outcrops in Bibb County, Alabama". Castanea. 66 (1–2): 154–205. JSTOR 4033889. Retrieved 23 March 2026.