Classification

Domain: Eukarya
Supergroup: Opisthokonta
Kingdom: Fungi
Phylum: Ascomycota
Class: Sordariomycetes
Order: Xylariales
Family: Xylariacaea
Genus: Xylaria
Species: Xylaria polymorpha

Below is the full classification of X. polymorpha starting from domain and ending with species, along with a description of why X. polymorpha  is placed in each group (the taxonomy is based upon the Species Fungorum website¹⁷ database and the UW-La Crosse organismal biology class lecture¹⁹).

Domain: Eukarya
X. polymorpha falls into the Eukarya domain because, like all eukaryotes, at the cellular level there are membrane bound organelles and a membrane bound nucleus containing linear chromosomes and a nucleolus¹⁹. Another cool member of Eukarya is Cinnamomum zeylanicum.

Supergroup: Opisthokonta
Some scientists hypothesize that organisms in opisthokonta all descended from an ancestor with a single posterior flagellum. Organisms placed in opisthokonta also have conserved ribosomal RNA sequences and proteins¹². This super group contains the animalia kingdom (which includes organisms such as Elephas maximus), fungi kingdom, and some protists (e.g. choanoflagellates)¹⁹.

Kingdom: Fungi
Distinctive characteristics of X. polymorpha classify it within the fungi kingdom. X. polymorpha does not have specialized tissue for the transportation of materials. In addition, X. polymorpha and most fungi undergo an alteration of generations life cycle, with asexual and sexual phases. All fungi use spores as a part of reproduction, which usually disperse via wind. Most fungi are not motile, but grow as thread-like structures called hyphae into an interwoven mesh called a mycelium. On the other hand, some fungi grow in a single-celled yeast form. A chitin based cell wall encloses the cell's of most fungi¹⁹. To learn about the magic mushroom found in the fungi kingdom, Psilocybe cubensis, click the hyperlinked scientific name.

Phylum: Ascomycota
These fungi produce sexual spores in internal sacs called asci. In addition, the ascomycota produce asexual spores externally called conidia. This group includes morels, cups, and other fungi, like X. polymorpha and Saccharomyces cerevisiae¹⁹.

Class: Sordariomycetes
This class of fungi, along with X. polymorpha and Cordyceps sinesis, have flask shaped bodies (perithecia) that contain many asci. Most sordariomycetes have asci with eight spores within each ascus. A well-known species in the this class is Magnaporthe grisea, the pathogen that causes rice blast¹⁶.

Order: Xylariales
Xylariales form a cushion-like plate of solid mycelium, called a stroma, and contain thick walled perithecia^5,15. Pigmented ascospores with germ pores or germ slits are another distinguishing characteristic of xylariales. X. polymorpha possesses all of these characteristics¹⁵.

Family: Xylariaceae
Along with the stroma and thick walled perithecia of other Xylariales, X. polymorpha and fungi in xylariaceae have an iodine-positive ascus apical ring. Most xylariaceae bear single-celled dark colored ascospores⁷. Xylariaceae range in ecological roles, from mostly decomposers of angiosperms to some plant pathogens to important endophytes¹¹.

Genus: Xylaria
Xylaria grow into black, firm club-like mature fruiting bodies. The Xylaria undergo complicated life cycles with various forms and colors at each stage, often making species identification difficult¹⁰.

Species: Xylaria polymorpha
The word "Xylaria" comes from the latin prefix xyl- meaning wood, indicating this fungus grows on wood. "Polymorpha" derives from the latin prefix poly - meaning many and the latin suffix - morph meaning form or shape, indicating the multiple forms of X. polymorpha that appear in nature^9,18.

To learn about the phylogeny of Xylaria polymorpha, click the hyperlinked word to the left.