Flavocetraria minuscula

Cladocetraria is characterised by its distinctive upright (erect) growth form, with leaf-like structures that form hollow tubes. The main body of the lichen, the thallus, grows 2–3 cm tall (occasionally reaching 4 cm) and measures 0.5–3 mm in width. The tubes are typically branched once or twice in a fork-like pattern. One of the most distinctive features of the genus is the peculiar shape of its branch tips, which curl inward like small helmets and show faint patches of white powdery coating (pruina). The upper surface, which faces the inside of the tube, appears yellowish-green to green and has a smooth, glossy texture. The lower surface, forming the outside of the tube, ranges from pale yellowish-green to pale green and is also smooth. At the base of the plant, the tissue often takes on a reddish colouration. The margins of the tubes may occasionally grow together (become fused), and along these edges, the lichen develops special pore-like structures called pseudocyphellae. These appear as a dotted line pattern along the margins and help the lichen exchange gases with its environment. This arrangement of pseudocyphellae is an important characteristic that helps distinguish Cladocetraria from related genera.

Cladocetraria minuscula has a Northern Hemisphere distribution, primarily occurring in northeastern Asia and northwestern North America, particularly the Russian Far East. The species is notably absent from Northern Europe, suggesting a circumpolar distribution similar to other members of the cetrarioid core group. In Asia, the species occurs mainly in the Russian Far East, with documented populations across several regions of Siberia. The species occurs throughout the Republic of Sakha (Yakutia), Transbaikal Territory, Khabarovsk Territory, and the Magadan Region. Additional populations have been documented in the Kamchatka Territory and Chukotka Autonomous Area. On the Taimyr Peninsula, the species has been found in Dryas-Carex-moss tundra, while in the Irkutsk Region at the Stanovoe Upland, it occurs in mountain stony lichen tundra at elevations around 1200 m. In North America, the species is common in Interior Alaska, where it grows in patches alongside F. cucullata. First reported from Denali National Park and the Chena River area, it occurs at several additional locations including the Delta Junction region, along the Alaska Highway southeast of Tok, and in the Southeast Fairbanks Borough. Canadian populations have been documented in Nahanni National Park, Northwest Territories, at elevations between 450–500 m. …