Observation 12940: Rhizocarpon grande (Flk. in Flot.) Arn.
When: 2008-10-15
Herbarium specimen reported

Notes: Crustose lichen, on granite.
THALLUS: light to medium gray, areolate, areoles thick and strongly convex and (0.38)0.58+/-0.13(0.86) mm (N=17), K-, C-, dull
MEDULLA: white, K-, C+ pink to weakly red, strongly POL+ white clearing in K
ALGAE: algal layer thick and continuous
APOTHECIA: black, lecideine, appear sunken between areoles; rim black, prominant, smooth, shiny, even; disc black, flat to slightly convex, epruinose, to around 0.8 mm; epihymenium black, K+ weakly violet, C-, POL-; hymenium clear, POL-, K-, C-, K/I+ blue; hypothecium dark brown to black; paraphyses strongly conglutinated
SPORES: 8 per ascus, clear when young to dark brown when older, strongly muriform, (30)32+/-2(35) x (15)17+/-1(18) µm (Q=(1.6)1.9+/-0.2(2.1)) (N=9)


Lecidea in bottom left corner.
Lecidea in upper right.
Two little Rhizocarpon amid sea of Lecidea.
Rhizocarpon off on right side.
Aspicilia center to left, brown in upper right is Lecidea, and the gray-and-black along bottom to right is Rhizocarpon.
Mostly Aspicilia, brown is Lecidea, little gray-and-black is Rhizocarpon.
Areoles, at 30×.
Apothecial section, in water, at 100×.
Muriform spores in ascus, in water, at 1000×.
Immature spores in ascus, in water, at 1000×..

Proposed Names

87% (1)
Eye3 Eyes3
Used references: Nash’s Sonoran Flora
Based on microscopic features: Eight brown muriform spores per ascus.
Based on chemical features: C+ red medulla

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Eye3 = Observer’s choice
Eyes3 = Current consensus


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Created: 2008-10-19 22:03:21 PDT (-0700)
Last modified: 2008-10-19 22:03:21 PDT (-0700)
Viewed: 24 times, last viewed: 2016-10-26 14:22:01 PDT (-0700)