Hypogymnia is a genus of foliose lichens in the family Parmeliaceae. They are commonly known as tube lichens, bone lichens, or pillow lichens. Most species lack rhizines that are otherwise common in members of the Parmeliaceae, and have swollen lobes that are usually hollow. Other common characteristics are relatively small spores and the presence of physodic acid and related lichen products. The lichens usually grow on the bark and wood of coniferous trees.
Hypogymnia occidentalis, commonly known as the lattice tube lichen, is a species of foliose lichen in the family Parmeliaceae. It is found in North America, where it grows on the lower trunks of conifers, particularly Douglas-fir.
Hypogymnia laxa is a species of foliose lichen in the family Parmeliaceae. Found in the Chinese Himalayas, it was described as a new species by Bruce McCune in 2003. The type specimen was collected from the Jiaozi Snow Mountain in Luquan County (Yunnan), at an elevation of 3,750 metres (12,300 ft). Here it was found growing on the bark and wood of Abies, Pinus, and Rhododendron. The lichen is characterized by a thallus with soredia, the presence of physodalic acid in the medulla, and rimmed holes on the lower surface. This latter feature distinguishes it from the morphologically similar Hypogymnia pseudophysodes, which always has unrimmed holes.
Hypogymnia diffractaica is a species of foliose lichen in the family Parmeliaceae. Initially reported from Southwest China, it was described as a new species by Bruce McCune in 2003. The type specimen was collected in Jiulong County, at an elevation of 3,000 metres (9,800 ft). Here it was found growing on the bark and wood of Rhododendron; it has also been recorded on birch. It is characterized by its slender lobes, the rimmed holes on the lower surface, and the presence of the chemical diffractaic acid as the main secondary metabolite in the medulla. It has a lower surface that is expanded and puffed out. Hypogymnia hengduanensis, the only other Hypogymnia species containing diffractaic acid as the main medullary substance, is quite similar in appearance, but can be distinguished from H. diffractaica by the presence of isidia. It also tends to grow at slightly lower elevations. In 2018, H. diffractaica was recorded from Bhutan.
Hypogymnia congesta is a rare species of foliose lichen in the family Parmeliaceae. Found in China, it was formally described as a new species in 2003. The lichen grows on the bark and wood of conifers and bamboo. Hypogymnia congesta has a brown to brownish-grey foliose thallus measuring up to 8 cm (3.1 in) long or broad, with a cartilage-like texture. The lichen is chemically distinct, containing physodic acid and virensic acid; the latter substance is otherwise unknown from genus Hypogymnia.
Hypogymnia bulbosa is a species of foliose lichen in the family Parmeliaceae. Found in Southern China, it was described as a new species by Bruce McCune and Li-Song Wang in 2003. The type specimen was collected from the Zi ben Mountain in Cao County (Yunnan). There it was found growing on a spruce stump. It has also been recorded growing on the bark and wood of fir, willow, and Rhododendron. It is known to grow at elevations ranging between 2,800–3,800 metres (9,200–12,500 ft), generally in conifer forests. The lichen is characterized by features such as the rimmed holes on the lower surface of the thallus, the presence of the chemical physodalic acid, and the adundant budding.
Hypogymnia krogiae, commonly known as the freckled tube lichen, is a species of foliose lichen in the family Parmeliaceae. Found in North America, it was described as a new species in 1973 by Karl Ohlsson. The type specimen was collected near Cheat Bridge, West Virginia by Mason Hale in 1956.
Hypogymnia flavida is a species of foliose lichen in the family Parmeliaceae. It is found in mountainous locations of east Asia, where it grows on the bark and wood of woody plants. It has a relatively large yellowish thallus.
Hypogymnia papilliformis is a rare species of foliose lichen in the family Parmeliaceae. Found in China and the Russian Far East, it was formally described as a new species in 2015 by Bruce McCune, Svetlana Tchabanenko, and Xin Li Wei. The type specimen was collected by the second author in the Lazovsky Nature Reserve at an altitude of 600 m (2,000 ft); here, in a mixed conifer–broadleaved forest, it was found growing on Korean pine. The lichen has also been recorded from a mixed forest in the mountains of Shaanxi Province in China, at an altitude of 1,500 m (4,900 ft). The specific epithet papilliformis alludes to the papillose texture of the upper thallus surface. Secondary compounds that occur in Hypogymnia papilliformis include atranorin, and physodic acid as major metabolites, and minor amounts of 2'-O-methylphysodic acid and vittatolic acid.
Candelaria concolor, commonly known as the candleflame lichen or the lemon lichen, is an ascomycete of the genus Candelaria. It is a small foliose lichen dispersed globally.
Xanthoparmelia cumberlandia is a lichen which belongs to the Xanthoparmelia genus. It is also known as a member of the rockfrong lichens due to its coloration.
Hypogymnia irregularis is a species of corticolous (bark-dwelling) and lignicolous (wood-dwelling), foliose lichen in the family Parmeliaceae. Found in Asia, it was formally described as a new species in 2011 by lichenologist Bruce McCune. The type specimen was collected by the author from Jiaoxi Mountain at an altitude of 3,700 m (12,100 ft), where it was found growing on the bark of Abies. It has since been recorded growing on the wood and bark of both conifers and hardwood trees. In addition to southwest China, where it is most common, it has also been collected from India, Nepal, Tibet, and Taiwan. The species epithet alludes to the irregular positioning of perforations on the lower surface of the thallus.
Hypogymnia pruinoidea is a species of foliose lichen in the family Parmeliaceae. Found in China, it was formally described as a new species in 2012 by Xin-Li Wei and Jiang-Chun Wei. The type specimen was collected from Mt. Taibaishan (Shaanxi) at an elevation of 2,800 m (9,200 ft), where it was found growing on the trunk of Abies. It is only known to occur at this location, a cool and moist montane environment supporting lichen-rich forests and woodlands. The species epithet refers to the pruinose upper thallus surface and lobe tips.
Hypogymnia capitata is a species of foliose lichen in the family Parmeliaceae. Found in high-elevation conifer forests in Sichuan Province, China, it was described as a new species in 2014. The lichen is characterized by its capitate terminal soralia, brownish lobes with white cavities, and the presence of olivetoric acid. This lichen is distinguished from similar species by its specific morphological, chemical, and habitat characteristics.
Hypogymnia nitida is a species of foliose lichen in the family Parmeliaceae. It has a glossy dark brown upper surface and a strongly wrinkled, convoluted lower surface. Found in China, it was described as a new species in 2014.
Hypogymnia pendula is a rare species of foliose lichen in the family Parmeliaceae. It is characterised by its pendulous (hanging) growth form and distinct chemical composition.
Hypogymnia saxicola is a rare species of foliose lichen in the family Parmeliaceae. Found in Yunnan and Sichuan provinces of China, it forms delicate cushions on mossy rocks in subalpine regions. It is characterised by its slender, glossy brown lobes and unique chemistry.
Hypogymnia tenuispora is a rare species of foliose lichen in the family Parmeliaceae. Found in China's Yunnan province, it is characterised by its uniquely narrow ascospores and crowded lobes, which help distinguish it from other similar Hypogymnia species.
Hypogymnia amplexa is a species of corticolous (bark-dwelling), foliose lichen in the family Parmeliaceae. It is found in the western United States and Canada.
Arctoparmelia incurva is a species of saxicolous (rock-dwelling), foliose lichen in the family Parmeliaceae. First described in 1794 by Christiaan Hendrik Persoon, it has undergone several taxonomic reclassifications before being placed in its current genus in 1986. This yellowish-green lichen, characterised by its narrow, convex lobes and globular soralia, typically grows on sun-exposed siliceous rocks in alpine and arctic habitats. It has a circumpolar distribution, found across North America, Europe, and parts of Asia. A. incurva can be distinguished from similar species by its specific morphological features and chemical spot test reactions. The lichen is known to host several parasitic fungi and has shown tolerance to acid pollution.
