lichens of the lower ozark region of missouri and arkansas

.................................................................... A. spectabile
Arthothelium spectabile A. Massal. [ARTSP] - crustose
Uncommon on lower and mid boles of trees in mesic, lightly shaded areas. This species can be
recognized by the well-developed, continuous, whitish gray thallus with abundant, irregularly rounded,
black apothecia typically to 0.5 × 1.5 mm.
Arthothelium taediosum (Nyl.) Müll. Arg. [ARTTA] - crustose
Frequent on a variety of smooth-barked trees in woodlands, especially on Quercus coccinea, Q.
rubra, and Q. velutina. This species occurs from mid boles upward into the canopy, but is almost
nonexistent at the bases of trees. The apothecia are notably smaller and more stellate-branched than
in A. spectabile, with individual clusters usually < 0.5 mm broad.
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ASPICILIA A. Massal. (Hymeneliaceae)
Saxicolous crustose lichens with gray to grayish green, continuous to areolate thalli and usually
immersed apothecia, paraphyses moniliform, photobiont Trebouxia, asci with a slightly thickened tip,
IKI-, with (4-6) 8 large, simple, hyaline, ovoid spores; 5 species in the region.
1. Thallus composed of discrete, thickened, gray areoles; apothecia immersed and sunken below level of upper
cortex, pruinose, with densely pruinose thalline rim; on carbonate rocks ................. A. contorta
1. Thallus continuous to rimose; apothecia immersed but not sunken, without pruina; on siliceous rocks.
2. Thallus K+ red (norstictic acid) ......................................... A. cinerea
2. Thallus K- or K+ yellow (norstictic acid lacking or present as a trace substance).
3. Thallus light to medium gray, K- ............................... A. caesiocinerea
3. Thallus pale to dark greenish gray, K+ yellow (stictic acid).
4. Thallus thin, smooth, continuous to rimose; usually near permanent water ... A. laevata
4. Thallus thick, rimose to subareolate; uplands .....................A. verrucigera
Aspicilia caesiocinerea (Nyl. ex Malbr.) Arnold [ASPCAE] - crustose
Occasional on shaded siliceous boulders and rock fragments in wooded uplands, occurring on chert,
granite, rhyolite, and sandstone. Interestingly, this species does not occur on massive ledges, but on
smaller boulders and fragments.
Aspicilia cinerea (L.) Körb. [ASPCI] - crustose
Occasional, with habitats and substrates similar to those of A. caesiocinerea. This species also
occurs on siliceous rocks in more moist situations along streams and seeps. [norstictic acid]
Aspicilia contorta (Hoffm.) Kremp. [ASPCO] - crustose
Occasional on exposed dolomite boulders and ledges in glades and on bluffs, usually in full sun to
light partial shade. The apothecia are typically whi te pruinose, and overlapped around thei r margins
by a zone of upper cortex that is heavily pruinose and appears almost sorediate.
Aspicilia laevata (Ach.) Arnold [ASPLA] - crustose
Apparently local, on hard, exposed siliceous rocks near permanent water, such as on massive igneous
exposures of shut-ins along Ozark streams. The thallus of this species is greenish tinged, as contrasted
with the light gray thalli of A. caesiocinerea and A. cinerea. [stictic acid, ± traces of norstictic acid]
Aspicilia verrucige ra Hue [ASPVE] - crustose
Rare on silicious rocks in xeric wooded uplands. This species is similar in color and chemistry to
A. laevata, but has a thicker, areolate thallus and typically occurs in uplands, as opposed to the typical
streamside habitat of A. laevata. [stictic acid, ± traces of norstictic acid]
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