Observation 10601: Toninia tristis (Th. Fr.) Th. Fr.
When: 2008-06-08
Herbarium specimen reported

Notes: crust lichen, on soil/moss, in shelter of sandstone boulder
THALLUS: very bullate, rich brown to olive-brown to greenish, covered with tiny raised black dots, several perforations, K-, C-, KC-
MEDULLA: white, K-, C-, KC-
ALGAE: green
APOTHECIA: black discs sunkend between areoles, plane, soon immarginate, lecideine; epihymenium dark brown, K+ weak violet-red; hymenium yellow/orange-brown, K+ weak violet-red; hypothecium yellow/orange-brown and K+ weak violet red fading into greenish below; exciple dark brown, K-; paraphyses 3-4 µm wide, often branched, expanded at tips sometimes a few cells deep making it submoniliform, dark brown caps, stuck together strongly at tips; asci IKI+ blue tip with paler well-defined canal
SPORES: 4 per ascus (supposed to be 8 and maybe there are but there are very few spores and the asci are impossible to separate out before they burst), comet-shaped (rounded on one end and tapered on the other end), clear, simple to occasionally 1-septate, (15)18+/-2(23) x (3.6)4.6+/-0.6(6.1) µm (Q=(2.9)4.0+/-0.5(5.0)) (N=21)

Tough one to diagnose because of the ambiguous nature of thallus: is it squamulose or crustose? Are the rare apothecia parasites or part of the thallus? But photos on the web (especially Timdal’s) look just like mine. But no one mentions the tiny raised back dots all over the thallus — a parasite??

Species Lists

Images

20128
20129
10x magnification
20130
30x magnification (black thing is apothecium)
20131
apothecial section, in water, at 100x
20132
apothecial section, in water, at 100x, in cross-polarized light
20133
apothecial section, in KOH, at 100x, showing weak red-violet reaction in hymenium
20134
spore, in KOH, at 1000x
20135
paraphyses, in KOH, at 1000x

Proposed Names

87% (1)
Eye3 Eyes3
Used references: Nash’s Sonoran Flora, Brodo’s Lichens of North America, and Field Guide to Biological Soil Crusts of Western U.S. Drylands by Rosentreter, et al.

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Eye3 = Observer’s choice
Eyes3 = Current consensus

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Created: 2008-09-07 16:52:58 PDT (-0700)
Last modified: 2008-09-07 16:52:58 PDT (-0700)
Viewed: 130 times, last viewed: 2016-09-11 22:21:45 PDT (-0700)