I recently worked with James Lendemer of the New York Botanical Garden on a paper that sorts out the taxonomy of the
Cladonia lichens in eastern North America that carry out a full sexual life cycle without ever producing podetia (Lendemer & Hodkinson 2009). Since podetial morphology is typically the most informative character (or set of characters) used for identifying
Cladonia specimens, this group has previously been either neglected or treated in a very incomplete manner. We used a combination of molecular and morphological analyses to better define the morphological/ecological/biogeographical boundaries of several named species, and were able to describe an entirely new species that is well-supported by morphology, ecology, chemistry, and gene sequence data. The new species is known as
Cladonia stipitata Lendemer & Hodkinson. It has an interesting morphology that includes a narrow, blackened stipe upon which the squamules sit. The underside of some extremely well-developed specimens on barren rock can have a substantial mass of these distinct thin black stipes, something quite unique in the genus
Cladonia.
Plate 5 (Lendemer & Hodkinson 2009). Cladonia stipitata. Figure 1, thallus (Harris 30810, scale = 5 mm). Figure 2, detail of the primary squamules (Harris 38010, scale = 1mm). Figure 3, typical habitat (Jackson Co., North Carolina, USA, photo by E.A. Tripp). Figure 4, detail of apothecium (Lendemer 7615, scale = 2 mm).
In the paper, we also provide a key to the typically sterile
Cladonia lichens in eastern North America (which includes many species that have their reproductive structures on podetia, but only rarely reproduce sexually and are therefore without podietia in most collections) and briefly discuss some of the potential forces at work in the evolution of fungal introns. The title of the work is "The Wisdom of Fools: new molecular and morphological insights into the North American apodetiate species of
Cladonia", and it is derived from a quote by Dr. Richard C. Harris ("Dick", from the New York Botanical Garden) stating that "the common wisdom [is] that only fools collect sterile
Cladonia" (Harris 1992; note: species that complete the sexual lifecycle without producing podetia are typically grouped in with the 'sterile' species due to their odd mode of reproduction). Feel free to read our paper
here, or check it out in volume 7 of
Opuscula Philolichenum (
Festschrift für Richard C. Harris).
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Brendan Hodkinson, Duke University
Works Cited:
Harris, R. C. 1992.
Cladonia petrophila, a new species from eastern North America.
Brittonia 44(3): 326-330.
Lendemer, J. C., and B. P. Hodkinson. 2009. The Wisdom of Fools: new molecular and morphological insights into the North American apodetiate species of
Cladonia.
Opuscula Philolichenum 7: 79-100.
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