Yellow pigments in the Parrot Toadstools could be the key of their Taxonomy
The Parrot Toadstool, Hygrocybe psittacina (Hygrophoraceae) is one of the most popular green mushrooms. The green color of this fungus is not permanent. They are Initially green with shades of yellow, orange or purple, but as it grows and the bell-shaped cap expands, it turns more yellow, sometimes retaining an orange or purplish tinge as the green slime washes off the cap.
The color of this species is due to the presence of a yellow pigment called muscaflavin, also present in some other species of Hygrocybe and a few other fungi. Muscaflavin in Hygrocybe species is accompanied by other pigments named hygroaurins.
The presence of muscaflavin pigments is a remarkable chemotaxonomical character in fungi, since its presence in different species allows to establish relationships between taxa. This is useful, because the distinction of species and their taxonomy, especially in the genus Hygrocybe is not always clear and unambiguously through macroscopic, and even microscopic, characteristics.
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Photo credit: ©Juraj Komar | Locality: Piešt̕any, Trnavsky, Slovakia