''Phaeoceros'' is 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 ...

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 ...

s in the

family Family (from ) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). It forms the basis for social order. Ideally, families offer predictabili ...

Notothyladaceae The Notothyladaceae is the only family of hornworts in the order Notothyladales. Description Plants in the Notothyladaceae grow as a solid, flattened green structure ( thallus) without internal air spaces, unlike some other hornwort families ...

. The genus is global in its distribution. Its name means 'yellow horn', and refers to the characteristic yellow

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 the plants produce in the horn-shaped

sporophyte A sporophyte () is one of the two alternation of generations, alternating multicellular organism, multicellular phases in the biological life cycle, life cycles of plants and algae. It is a diploid multicellular organism which produces asexual Spo ...

. The genus ''Phaeoceros'' was first recognized in 1951 by Johannes Max Proskauer. The type species is '' Phaeoceros laevis''. The genus is distinguished by having yellow spores, different

chloroplast A chloroplast () is a type of membrane-bound organelle, organelle known as a plastid that conducts photosynthesis mostly in plant cell, plant and algae, algal cells. Chloroplasts have a high concentration of chlorophyll pigments which captur ...

structure, relatively less frilliness of the

thallus Thallus (: thalli), from Latinized Greek (), meaning "a green shoot" or "twig", is the vegetative tissue of some organisms in diverse groups such as algae, fungi, some liverworts, lichens, and the Myxogastria. A thallus usually names the entir ...

when compared to ''Anthoceros'', and a relative lack of internal cavities in ''Phaeoceros''. The yellow color of the spores is the easiest way to distinguish ''Phaeoceros'' from the common genus ''

Anthoceros ''Anthoceros'' is a genus of hornworts in the family Anthocerotaceae. It is distributed globally. Species of ''Anthoceros'' are characterized by having a small to medium-sized, green thallus that is more or less lobed along the margins. Etym ...

'', which produces spores that are dark brown to black. ''Phaeoceros'' is often confused with ''Anthoceros'', and dried plants are particularly difficult to distinguish in, but the two genera can always be recognized, when fertile and mature, by the spores. When sterile, the distinguishing characteristic is the absence of lacunae (gaps within the tissue) within the thallus, which in ''Anthoceros'' are large and numerous.

References

* Proskauer, J. (1951). "Studies on Anthocerotales. III". ''Bull. Torrey Bot. Club'' 78: 331–349.

External links

Description and photos
Hornwort genera {{Bryophyte-stub