Loxospora cristinae is a fungal species classified in 2018, found in a few European countries. It belongs to the division Ascomycota and the family Sarrameanaceae. It was first identified and described in the 19th century, but the species would not be correctly classified until almost two centuries later. Loxospora cristinae is a sterile crustose lichen, meaning it reproduces by a type of vegetative spore that has evolved specifically to produce morphological structures.
Taxonomy
Loxospora cristinae was first classified by Swiss biologist Anton Gisler in the 1800s in central Switzerland. In the mid-1900s, its presence was documented in several other regions of Switzerland. Then in 1989, it was documented in the Swiss forest Meriwald. In 1991, it was incorrectly classified as Lecidella alba, a rim lichen that has roughly circular fruiting discs. Shortly after in 1992, the species was examined by more experienced lichenologists, but a conclusive classification could not be reached.
A little over two decades later in 2015, it was recorded for the first time in the Rothwald forest of Austria. This forest lies in the Northern Limestone Alps in the southwest of lower Austria. Rothwald forest is a protected area, and as a result, scientists had limited accessibility to this area and could not study the development of Loxospora cristinae.
Finally in 2018, Polish researchers performed field lichen inventories and herbarium studies in Poland's forests. They came across a sterile crustose lichen species and collected 18 specimens in total for future examination. After completing DNA extraction and sequencing, PCR amplification, and phylogenetic analysis, they came to the conclusion that this was a fungal species recorded only a few other times. They named this species Loxospora cristinae in honor of Polish lichenologist Krystyna Czyzewska, a researcher who has contributed significantly to the knowledge of lichen diversity in Poland. Loxospora cristinae forms a distinct and highly supported clade. Later that same year, Loxospora cristinae was identified in the Black Forest in Germany. In 2019, it was rediscovered and recognized in Swiss forests. Similar species have been documented in Ukraine, but this species has yet to be identified there. Because of the rarity of its occurrence and the fact that it is difficult or nearly impossible to classify sterile lichens based on morphological data, the precise classification of Loxospora cristinae remains unknown. Molecular methods and DNA markers were needed to classify this species.
Description
Loxospora cristinae is a sterile lichen, meaning that it lacks ascomata, a feature that helps to determine the systematic position of a fungus. This is another reason it has been so difficult to classify.
The thallus surface is smooth to cracked areolate, with a finely cracked cortex, exposing the underlying medulla. The cortex may also be folded. Loxospora cristinae is partly verruculose (warty); these verruculose parts are about 300 μm in width. The non-verruculose parts are up to 120 μm thick. This species has a grayish white to greenish white thallus, measuring 0.5 cm wide and 2.5 cm in diameter. On the thallus are localized structures of soredia (powdery propagules) called soralia. Soralia are either confluent from the beginning or are at first discrete and punctiform, become irregular, and then form a granular, somewhat continuous crust. They are white to greenish gray and sometimes appear pale brown in color and are 35–75 μm in diameter. The soredia wall is distinct with some short, projecting hyphae.
Habitat and ecology
Loxospora cristinae is usually found in a moderately oceanic climate in regions with short, cool summers, and long, snow-rich winters. Rainfall occurs year-round, averaging in some areas. The highest temperature difference across regions where this fungus is found is , with the lowest temperature difference being . Loxospora cristinae likes shady conditions with high air humidity.