Brief Summary

Read full entry


 Thallus: foliose, small, 2-10 mm wide, forming rounded cushions or ±spreading and up to 5 cm across; lobes: few, 0.5-.15 mm wide, flattened, appressed to erect, usually repeatedly branched, distinctly swollen with entire or crenate to lobulate margins; upper surface: dark olive-green to somewhat brown or black, dull, epruinose, smooth or sometimes verrucose; isidia: absent; lower surface: usually paler than the upper surface; Apothecia: in var. conglomeratum usually numerous, crowded, often hiding the lobes, often compressed, sessile, with constricted base on lobe margins or terminal on tip of lobules, 0.5-1.5(-2) mm wide; in var. crassiusculum more scattered, not hiding the lobes, 0.5-1.5(-2.5) mm wide; disc: plane to convex, dark red to reddish brown, usually glossy, smooth, epruinose; thalline exciple: rather thick, eventually disappearing, entire, smooth, inconspicuous or slightly prominent; pseudo-cortex: absent or poorly developed; true exciple: thin, up to 20 µm thick in central part, euthyplectenchymatous or rarely almost subparaplectenchymatous; hymenium: hyaline, 60-80 µm tall; asci: clavate, small, 40-50 x 13-17 µm, 8-spored; ascospores: hyaline, fusiform with acute apices (to partly subovoid or short-ellipsoid), rarely constricted at septa, (8.5-)10-24(-26) x 3-4.5(-6.5) µm; Pycnidia: common, immersed, +globose; conidia: bacilliform, usually slightly swollen towards the ends, 3-4 x 1 µm; Spot tests: all negative; Secondary metabolites: none detected.; Substrate and ecology: on bark in nutrient-rich sites in woodlands and forests of the mountains; World distribution: North America and Europe; Sonoran distribution: central and southern Arizona, Baja California, Baja California Sur, Sonora, and Chihuahua.; Notes: There are three varieties of Collema conglomeratum, all of which occur in the U.S.A. In the Sonoran Region, however, only var. conglomeratum and var. crassiusculum were observed. They are characterized by their swollen, folded and plicate lobes, the euthyplectenchymatous proper exciple, their fusiform 2-celled ascospores, and the corticolous habitat. In var. conglomeratum the thallus is roundish with crowded apothecia terminal on the tips or margins or short lobes; whereas in var. crassiusculum, the thallus is more spreading with appressed, elongated, marginal lobes and densely plicate, swollen, erect lobes in the center. 


Creative Commons Attribution Non Commercial Share Alike 3.0 (CC BY-NC-SA 3.0)

© Lichen Unlimited: Arizona State University, Tempe.

Source: Lichen Flora of the Greater Sonoran Desert Region

Belongs to 0 communities

This taxon hasn't been featured in any communities yet.

Learn more about Communities


EOL content is automatically assembled from many different content providers. As a result, from time to time you may find pages on EOL that are confusing.

To request an improvement, please leave a comment on the page. Thank you!