Alleniella is a genus of mosses in the family Neckeraceae (order Leucodontales, class Bryopsida), established in 2011 by S. Olsson, J. Enroth, and D. Quandt based on phylogenetic analysis that segregated these species from the larger genus Neckera. The genus name honours the American bryologist Bruce Hampton Allen (b. 1952).
Members of this group — like their former Neckera relatives — are medium-sized to large pleurocarpous mosses that form extensive, shiny, light green to yellowish shelf-like growths on vertical substrates. Stems reach up to 15 cm in length, are irregularly to regularly pinnately branched, and frequently produce flagella (thin, whip-like branches with reduced scale-shaped leaves). The shoot tips stand horizontally and are often arranged in a step-like fashion.
Leaves range from erect to spreading and vary in shape from ovate and oblong to tongue-shaped or lanceolate, with margins entire to serrate. The costa (midrib) is typically short and double or sometimes entirely absent. Leaf cells are prosenchymatous, becoming shortened and rhombic toward the apex. Capsules are cylindric, oblong, or globose, borne on setae 0.1–1.2 cm long.
The type species, Alleniella complanata (formerly Neckera complanata, the flat Neckera), is notably the moss species discovered in the digestive tract of the Tyrolean Iceman (Ötzi), the ~5,300-year-old natural mummy found in the Alps.
Etymology
The genus Alleniella was named in honour of Bruce Hampton Allen (b. 1952), an American bryologist at the Missouri Botanical Garden, in recognition of his contributions to bryology and the study of the Neckeraceae family.
Distribution
Alleniella has a cosmopolitan distribution, with species occurring in temperate and tropical regions worldwide. Alleniella complanata, the type species, is widespread in the temperate latitudes of the northern hemisphere, particularly in Central Europe where it is common in upland areas and the Alps, especially on limestone substrates, and rarer in the lowlands.
Ecology
Alleniella species are predominantly epiphytic and epilithic mosses, growing on vertical substrates. Alleniella complanata favours calcareous rocks, less frequently occurring on non-calcareous rocks or tree bark. The mosses form shiny, extensive mats and typically grow on vertical surfaces with their shoot tips oriented horizontally. Reproduction is either autoicous (male and female structures on separate branches of the same plant) or dioicous (separate male and female plants).
Taxonomy Notes
The genus Alleniella was resurrected and established in 2011 by S. Olsson, J. Enroth, and D. Quandt in Taxon (Vol. 60, Issue 1, page 45). It was segregated from the large, cosmopolitan moss genus Neckera based on molecular phylogenetic analysis of the family Neckeraceae. Species previously classified as Neckera were transferred to Alleniella with new combinations. GBIF currently recognises two descendant species (A. besseri and A. complanata), though the literature recognises approximately nine species. Note that some taxonomic databases (including parts of GBIF) still list these species under Neckera, reflecting the recency of the split.
History
Alleniella complanata (formerly Neckera complanata) holds archaeological significance: fragments of this moss were identified among the intestinal contents of the Tyrolean Iceman (Ötzi), the extraordinarily well-preserved natural mummy dated to approximately 3300 BCE, discovered in the Ötztal Alps on the border between Austria and Italy.
