Spigelia alabamensis

Spigelia alabamensis
Spigelia alabamensis open flower
Spigelia alabmensis full plant with flower
Imperiled
Imperiled (NatureServe)[1]
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Embryophytes
Clade: Tracheophytes
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 6โ€“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

  1. 1 2 3 4 5 6 7 "Spigelia alabamensis". NatureServe Explorer. NatureServe. Retrieved 23 March 2026.
  2. 1 2 "Spigelia alabamensis (K.Gould) K.G.Mathews & Weakley". Plants of the World Online. Royal Botanic Gardens, Kew. 2026. Retrieved 23 March 2026.
  3. 1 2 3 4 Weakley, Alan S. "Spigelia alabamensis". Flora of the Southeastern United States (2025 edition). North Carolina Botanical Garden. Retrieved 23 March 2026.
  4. 1 2 Allison, James R.; Stevens, Timothy E. (2001). "Vascular flora of the Ketona dolomite outcrops in Bibb County, Alabama". Castanea. 66 (1โ€“2): 154โ€“205. JSTOR 4033889. Retrieved 23 March 2026.