Observation 34870: Pyxine subcinerea Stirton

When: 2010-03-12

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

Who: Chris Parrish (kitparrish)

Specimen available

Location: 35°12’38.36"N 85°54’0.40"W el. 587 m, Beckwith’s Point Trail.

Substrate and habitat: Many rosettes growing from 1 to 3 m above the ground on a slender hardwood tree about 12 cm DBH, in oak-hickory woodland near the rim of a widening canyon, on the western rim of the Cumberland Plateau.

cortex: UV+ bright banana yellow

Identification: Pyxine subcinerea is a small yellowish green sorediate rosette lichen 2 or 3 cm in diameter with prominent whitish pruina near the lobe tips and a cortex that fluoresces bright banana yellow. During the day, it blends into the background, but at night it becomes one of the most easiy identifiable Sewanee lichens. Even tiny thallus fragments less than 1 mm across glow bright yellow. The related Pyxine sorediata, which also occurs here, has a thallus with a characteristic blue-green aspect, reaches a diameter of about 8 cm, and is UV-. Pyxine sorediata is often encountered as a lone medallion on a tree trunk, while Pyxine subcinerea is often found in groups scattered up and down a slender smooth-barked branch.

Sharnoff’s Pyxine subcinerea gallery
CNALH images, description, and locality map, and a larger, interactive locality map.

Voucher specimen:
United States, Tennessee, Franklin County, Sewanee, Beckwith’s Point Trail. 12 Mar 2010. Chris Parrish 0073, det. James C. Lendemer (NY).

Common name: mustard lichen.

Species Lists


UV+ bright yellow cortex
same thallus (11 mm wide x 9 mm high) under white light

Proposed Names

85% (1)
Used references: Hinds and Hinds, 2005, pp.433-434; Flenniken, 1999, “The Macrolichens in West Virginia,” pp.193-194
Based on chemical features: thallus UV+ bright yellow

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= Observer’s choice
= Current consensus


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Created: 2010-03-16 21:54:45 PDT (-0700)
Last modified: 2010-06-09 00:01:07 PDT (-0700)
Viewed: 275 times, last viewed: 2019-02-02 04:23:19 PST (-0800)
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