''Leiosporoceros dussii'' is the only species in the
hornwort
Hornworts are a group of non-vascular Embryophytes (land plants) constituting the division Anthocerotophyta (). The common name refers to the elongated horn-like structure, which is the sporophyte. As in mosses and liverworts, hornworts have a ...
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
''Leiosporoceros''. The species is placed in a separate family, order, and
class
Class, Classes, or The Class may refer to:
Common uses not otherwise categorized
* Class (biology), a taxonomic rank
* Class (knowledge representation), a collection of individuals or objects
* Class (philosophy), an analytical concept used d ...
for being "
genetically and
morphologically distinct from all other hornwort lineages."
Cladistic
Cladistics ( ; from Ancient Greek 'branch') is an approach to biological classification in which organisms are categorized in groups ("clades") based on hypotheses of most recent common ancestry. The evidence for hypothesized relationships is ...
analysis of genetic data supports a position at the very base of the hornwort clade. Physical characteristics that distinguish the group include unusually small
spore
In biology, a spore is a unit of sexual reproduction, sexual (in fungi) or asexual reproduction that may be adapted for biological dispersal, dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores fo ...
s that are ''monolete'' and unornamented. Additionally, there are unique strands of ''
Nostoc
''Nostoc'', also known as star jelly, troll's butter, spit of moon, fallen star, witch's butter (not to be confused with the fungi commonly known as witches' butter), and witch's jelly, is the most common genus of cyanobacteria found in a variety ...
'' (
cyanobacteria
Cyanobacteria ( ) are a group of autotrophic gram-negative bacteria that can obtain biological energy via oxygenic photosynthesis. The name "cyanobacteria" () refers to their bluish green (cyan) color, which forms the basis of cyanobacteri ...
) that grow inside the plant parallel with its direction of growth. Unlike other hornworts with symbiotic cyanobacteria that enters through mucilage clefts, the mucilage clefts in Leiosporoceros is only present in young plants and then closes permanently once the cyanobacterial colonies have been established. Also
mycorrhiza
A mycorrhiza (; , mycorrhiza, or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plant's rhizosphere, the plant root system and its surroundings. Mycorrhizae play ...
and
pyrenoid
Pyrenoids are sub-cellular phase-separated micro-compartments found in chloroplasts of many algae,Giordano, M., Beardall, J., & Raven, J. A. (2005). CO2 concentrating mechanisms in algae: mechanisms, environmental modulation, and evolution. ''An ...
s are absent.
Advances in understanding of mycorrhizal-like associations in bryophytes
/ref> Male plants have been found in Panama.
References
Hornwort genera
Monotypic bryophyte genera
{{Bryophyte-stub