Ahti T., Pino-Bodas R. & Mccarthy J.W. 2018: Cladonia ignatii, an overlooked new lichen in eastern North America. – Herzogia 31: 630 – 638.
Cladonia ignatii is described as a new species from eastern North America (type from SW Ontario, Canada). It is a segregate of C. ramulosa, but can be distinguished by soredioid-isidioid structures on ecorticate podetia and basal squamules. Its distinction is also supported by DNA sequences (ITS rDNA and rpb2). Records are known from Ontario, Maine, Maryland, Missouri, New York, Pennsylvania, and Wisconsin.