When: 2009-03-08

Collection location: Sewanee, Franklin Co., Tennessee, USA [Click for map]

Who: Chris Parrish (kitparrish)

Specimen available

35°12’38.36"N, 85°54’0.40"W, el. 587 m. Beckwith’s Point Trail.
35°12’45.15"N, 85°53’47.26"W, el. 586 m, Sewanee-St.Andrew’s Trail.

Substrate and habitat: Growing on a stone wall marking the entrance to the university campus. The wall was built about 50 years ago from local sandstone.

Habitat: Oak-hickory woodland on the western rim of the Cumberland Plateau.

Beckwith’s Point Trail, 2009-03-08: 38710-38712
Sewanee-St.Andrew’s Trail, 2009-03-17: 39433-39441

Characterization: saxicolous shield lichen with
(1) jumbled lobes and lobules covering entire thallus surface
(2) small, appressed outer lobes
(3) thallus firmly appressed, but with patience can be removed mostly intact
(4) irregular, folded apothecia; margins of apothecia had been grazed off by herbivores
(5) no isidia, no soredia
(6) dense, immersed laminal pycnidia
(7) undersurface creamy white
(8) rhizines stout, translucent, unbranched, tan with darker brown or black tips

Chemistry: cortex C-, K+ yellow to red, KC- dissolves some of the red; medulla C-, K+ bright yellow to deep red, KC- cleared the red.

Identification: Specimens of this lichen were identified by Gary Perlmutter at the UNC Herbarium as Xanthoparmelia tasmanica (medulla PD+ orange).

Voucher specimen: Tennessee, Franklin County, Sewanee, Sewanee-St.Andrew’s Trail, 17 Mar 2009, Chris Parrish 0015, det. Gary Perlmutter (NCU)

Common name: shingled rock-shield (called X. somloënsis in Brodo, et al.)

Species Lists


Beckwith’s Point Trail, 2009-03-08
Beckwith’s Point Trail, 2009-03-08
Beckwith’s Point Trail, 2009-03-08
marginal lobe, 25x
jumbled lobes and lobules, 7.1x
jumbled lobes and lobules 10x
apothecia with rims eaten by herbivores, 7.1x
apothecium with rim eaten by herbivores, 20x
pycnidia, 25x
pycnidia, 50x
rhizines, 16x
rhizines, 20x

Proposed Names

28% (1)
Used references: Brodo, Sharnoff, Sharnoff, p.733
59% (2)
Used references: Brodo, Sharnoff, Sharnoff, p.740.
-50% (2)
Based on chemical features: medulla PD+ orange

Please login to propose your own names and vote on existing names.

= Observer’s choice
= Current consensus


Add Comment
Xanthoparmelia synonymy
By: Brendan Hodkinson (brendanhod)
2009-12-11 00:14:52 CST (-0600)

X. somloënsis (Gyelnik) Hale => X. stenophylla (Ach.) Ahti & D. Hawksw.
X. tasmanica auct. Amer. => X. hypofusca (Gyeln.) Hodkinson & Lendemer

Morphology in this group can be extremely variable, but the lower surface is not black (so it cannot be X. hypofusca) and there seem to be some marginal lobulae, which would suggest X. stenophylla, but this species is probably part of a complex that has yet to be untangled.

Ahti, T. & D. L. Hawksworth. 2005. Xanthoparmelia stenophylla, the correct name for X. somloënsis, one of the most widespread usnic acid containing species of the genus. Lichenologist 37: 363-366.
Hodkinson, B. P., R. C. Harris, and M. A. Case. 2009. A Checklist of Virginia Lichens. Evansia 26(2): 64-88.
[ http://www.duke.edu/~bph8/VirginiaLichens/checklist.html ]
Hodkinson, B. P., and J. C. Lendemer. 2011. Molecular analyses reveal distantly-related cryptic species in Xanthoparmelia tasmanica. Bibliotheca Lichenologica 106: 115-126.
[ http://www.duke.edu/~bph8/HodkinsonLendemer_2011.pdf ]