Eryngium ludovicianum
Eryngium ludovicianum (commonly known as savanna eryngo) is a species of flowering plant in the family Apiaceae. It is endemic to the West Gulf Coastal Plain of the south-central United States, where it occurs in eastern Texas and Louisiana.
Description
Eryngium ludovicianum is a perennial herb characterized by slender, erect stems and narrow, linear-lanceolate leaves. Leaves are typically 3–8 mm wide and bear relatively sparse marginal teeth.
In the 2024 revision of the Eryngium integrifolium species complex, the species was distinguished by its combination of narrow leaves, low density of marginal teeth, and overall gracile habit, separating it from morphologically similar taxa.
It is most similar to Eryngium lanceolatum, but differs in having narrower leaves and fewer teeth per unit length of the leaf margin.
Taxonomy
The species was first described by Thomas Morong in 1887. It was later treated as a variety of Eryngium integrifolium and, less commonly, associated with Eryngium virgatum.
A comprehensive revision of the Eryngium integrifolium species complex in 2024 reinstated Eryngium ludovicianum as a distinct species based on consistent morphological differentiation and geographic segregation.
This revision recognized several closely related species in the complex, including Eryngium lanceolatum, Eryngium mississippiense, and Eryngium altamaha.
Distribution and habitat
Eryngium ludovicianum is endemic to the West Gulf Coastal Plain, occurring in eastern Texas and Louisiana.
It inhabits seepages and depressions in longleaf pine ecosystems, typically in highly acidic soils.
The species has a more southerly istribution than Eryngium lanceolatum, which occurs primarily farther north and west.
Ecology
Eryngium ludovicianum is associated with wet savanna and seepage habitats within longleaf pine systems. These environments are typically maintained by periodic fire and characterized by seasonally saturated, acidic soils.
Flowering occurs from August to October.
Identification
Within the Eryngium integrifolium species complex, Eryngium ludovicianum can be distinguished by:
- Narrow leaves (typically 3–8 mm wide)
- Sparse marginal teeth (fewer per centimeter than related species)
- Occurrence in southern Gulf Coastal Plain seepage habitats
It differs from:
- Eryngium lanceolatum — broader leaves, more densely toothed margins
- Eryngium mississippiense — more robust habit and different geographic range
- Eryngium altamaha — restricted to the Altamaha River region of Georgia
See also
- Eryngium lanceolatum
- Eryngium mississippiense
- Eryngium altamaha
References
ludovicianum Category:Flora of the United States Category:Endemic flora of the United States Category:Plants described in 1887