Tuesday, March 30, 2010

Eagle Summit, Alaska

The summer before last I traveled to Alaska in search of lichens.  It was an amazing trip!  There were lichens aplenty (in terms of biomass); however, there was noticeably less diversity than one might find in temperate regions or, of course, tropical regions.  This did not diminish my excitement when I saw the lichens of the tundra piled high on top of one another all along the ground.  Here are just a few photos of the amazing lichens of Eagle Summit, near Fairbanks, Alaska:

Masonhalea richardsonii

Solorina crocea

Ophioparma ventosa

Dactylina arctica

Alectoria ochroleuca

Flavocetraria cucullata

Thamnolia vermicularis

Cladonia pleurota

Sphaerophorus globosus

Stay tuned for more photos from some of the other sites that I visited in Alaska!


[Funding for this excursion was provided by NSF Award DEB-0640956.]

Saturday, March 6, 2010

Cladonia stipitata Lendemer & Hodkinson, a new species (with squamules!)

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). 

-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.
Download publication (PDF file)