Tiarella in New England

A revised taxonomy of Tiarella in eastern North America was proposed in July 2021. (Nesom 2021) The new taxonomy was subsequently accepted by Plants of the World Online (POWO), Flora of the southeastern United States (FSUS), VASCAN, and others. iNaturalist (which follows POWO) split Tiarella cordifolia into five species in November 2022.

In New England, the new taxonomy reduces to a name change, from Tiarella cordifolia to Tiarella stolonifera. New Flora of Vermont (2015) and Flora Novae Angliae (2011) accept Tiarella cordifolia and Tiarella cordifolia var. cordifolia, respectively. As of May 2024, Go Botany (an online version of Flora Novae Angliae) recognizes Tiarella cordifolia var. cordifolia as well.

Prior to the split, the taxonomy of Tiarella in the southeastern U.S. was sorely in need of change, so the new taxonomy was welcomed by some (e.g., FSUS). To others, the name change appears to be arbitrary. Indeed, a significant number of iNaturalist users have pushed back on the change.

At this point, it would be helpful if the authors of New Flora of Vermont and Flora Novae Angliae rendered an opinion on the matter.

REFERENCES

Primary source:

• Nesom, Guy L. (2021). "Taxonomy of Tiarella (Saxifragaceae) in the eastern USA" (PDF). Phytoneuron. 31: 1–61.

Related journal articles:

• Tiarella cordifolia has been split (November 20, 2022)
• Observing and identifying Foamflowers in eastern North America (December 3, 2022)

Posted on May 15, 2024 04:05 PM by trscavo