Vulpicida


Vulpicida is a genus of lichenized fungi in the family Parmeliaceae. Circumscribed in 1993 to contain species formerly placed in Cetraria, the genus is widespread in Arctic to northern temperate regions, and contains six species. The genus is characterized by the presence of the secondary metabolites pulvinic acid and vulpinic acid, compounds that when combined with usnic acid, give the species their characteristic yellow and green colors.

Taxonomy

The genus was circumscribed by Jan-Eric Mattson and Ming-Jou Lai in a 1993 Mycotaxon publication, to contain yellow species containing vulpinic and pinastric acids and a broadly club-shaped ascus. Mattson published a monograph of the genus later that year. The group of species assigned to the genus were previously recognized as a distinct grouping by Finnish lichenologist Veli Räsänen in 1952, who classified them in the genus Cetraria, subgenus Platysma, section Flavidae, and subsection Cucullatae. The type species is Vulpicida juniperinus, originally Lichen juniperinus as described by Carl Linnaeus in the second volume of his 1753 Species Plantarum.
The generic name Vulpicida is derived from the Latin words vulpes and -cida ; according to Swedish peasant folklore, the lichen, when consumed, kills foxes but not dogs or wolves.
According to a 2009 molecular analysis using internal transcribed spacer data from five of the six known species, Vulpicida is supported as monophyletic when using Bayesian analysis. Using a different method for phylogenetic inference, PAUP, the genus is paraphyletic, as Allocetraria nests within the same clade.

Description

The thallus ranges in form from foliose and forming rosettes, to somewhat fruticose, with lobes usually dorsiventral with raised tips, sometimes even cylindrical or slightly tapering. The upper thallus surface is bright to dark yellow, sometimes greenish, often wrinkled or somewhat folded. The lower thallus surface is weakly yellow, with black central parts, and lacks pseudocyphellae. The rhizinae are laminal, almost never close to the margin and rather sparse, and either simple or irregularly branched.
The apothecia are somewhat marginal or laminal, and comprise a brown disc with an often finely scalloped edge. The asci are broadly club-shaped, with a wide ocular chamber, and large axial body. The thallus often has a strong staining reaction in Lugol's solution. Spores are spherical or nearly so, and number eight per ascus. Pycnidia are typically abundant, with either a marginal or laminal arrangement. They are generally conspicuous, black, situated on projections, and raised or immersed. The medulla is yellow to orange. The pycnidial wall contains some black pigment. The conidia are somewhat flask-shaped or lemon-shaped. The genus is characterized by the presence of the secondary metabolites pulvinic acid and vulpinic acid, which are derived from the shikimic acid biosynthetic pathway. These compounds, combined with usnic acid, give the species their characteristic yellow and green colors.

Species

There are four species in Vulpicida, after a taxon merge in 2014. They are all found in arctic or boreal regions of the Northern Hemisphere.
V. canadensisV. pinastriV. viridisV. juniperinus complex