''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 Mason Ellsworth Hale, Jr. (September 23, 1929 – April 23, 1990) was one of the most prolific lichenologists of the 20th century. Many of his scholarly articles focused on the taxonomy of the family Parmeliaceae. Hale was one of the first liche ...

in 1956.

Description

The lichen has a greenish-gray thallus measuring up to in diameter. The thallus comprises individual overlapping lobes that are wide, with slightly upturned edges on the marginal lobes. The thallus undersurface is dark brown to black and wrinkled, but becoming lighter-colored near the lobe tips. Apothecia (sexual fruiting bodies) are common on the thallus surface; they are on a small stalk (stipitate), have a brown disc and are 2.0–3.0 mm wide. The ascospores number 8 per

ascus An ascus (; ) is the sexual spore-bearing cell produced in ascomycete fungi. Each ascus usually contains eight ascospores (or octad), produced by meiosis followed, in most species, by a mitotic cell division. However, asci in some genera or s ...

and measure 4.0–6.0

μm The micrometre ( international spelling as used by the International Bureau of Weights and Measures; SI symbol: μm) or micrometer (American spelling), also commonly known as a micron, is a unit of length in the International System of Unit ...

. ''Hypogymnia krogiae'' contains the secondary compounds atranorin, chloroatranorin, physodic acid, physodalic acid, and trace amounts of protocetraric acid. The expected results for standard chemical spot tests on the medulla are PD+ (red), K−, KC+ (pink), and C−. ''Hypogymnia krogiae'' reproduces by sexual means (via the apothecia) and does not have any soredia. It has a sorediate counterpart, ''

Hypogymnia incurvoides ''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 (root-like attachment organs on the lower surface) that are otherwi ...

'', which is also found in North America. This pair is one of three such fertile/sorediate species pairs in the genus ''

Hypogymnia ''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 (root-like attachment organs on the lower surface) that are otherwise c ...

''.

Habitat and distribution

''Hypogymnia krogiae'' occurs in eastern North America from Tennessee and North Carolina, north to Quebec in Canada. It is a

corticolous lichen A corticolous lichen is a lichen that grows on bark.Alan Silverside's Lichen Glossary (a-f), Alan Silverside/ref> This is contrasted with lignicolous lichen, which grows on wood that has had the bark stripped from it,Alan Silverside's Lichen Glos ...

, and grows on

fir Firs (''Abies'') are a genus of 48–56 species of evergreen coniferous trees in the family (biology), family Pinaceae. They are found on mountains throughout much of North America, North and Central America, Europe, Asia, and North Africa. The ...

and

spruce A spruce is a tree of the genus ''Picea'' (), a genus of about 35 species of coniferous evergreen trees in the family Pinaceae, found in the northern temperate and boreal (taiga) regions of the Earth. ''Picea'' is the sole genus in the subfami ...

trees in both open and shaded forests.

References

{{Taxonbar, from=Q15015288 krogiae Lichen species Lichens described in 1973 Lichens of Eastern Canada Lichens of the United States Fungi without expected TNC conservation status