Dendroceros
Encyclopedia
Dendroceros is a genus
of hornwort
s in the family
Dendrocerotaceae
. The genus contains about 51 species native to tropical and sub-tropical regions of the world.
is yellowish-green and usually less than one-half cm wide. The thallus branches in a bifurcating pattern. In the subgenus Apoceros, there are cavities in the central strand of the thallus. The edges of the thallus are only a single layer of cells thick and have an undulating margin. It is common to find symbiotic colonies of blue-green bacteria (usually Nostoc
) growing among the cells. Under a microscope, the epidermal cells have trigones.
The sporophyte
is erect when mature, growing up to 5 cm tall. Like other hornworts, its surface has stomata. The interior of the sporophyte differentiates into a central column and a surrounding mass of spore
s and elater
cells, with a distinct spiral. The spores are both green and relatively large with an ornamented surface.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of hornwort
Hornwort
Hornworts are a group of bryophytes, or non-vascular plants, comprising the division Anthocerotophyta. The common name refers to the elongated horn-like structure, which is the sporophyte. The flattened, green plant body of a hornwort is the gametophyte plant.Hornworts may be found worldwide,...
s in the family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
Dendrocerotaceae
Dendrocerotaceae
The Dendrocerotaceae is the only family of hornworts in the order Dendrocerotales....
. The genus contains about 51 species native to tropical and sub-tropical regions of the world.
Description
The gametophyteGametophyte
A gametophyte is the haploid, multicellular phase of plants and algae that undergo alternation of generations, with each of its cells containing only a single set of chromosomes....
is yellowish-green and usually less than one-half cm wide. The thallus branches in a bifurcating pattern. In the subgenus Apoceros, there are cavities in the central strand of the thallus. The edges of the thallus are only a single layer of cells thick and have an undulating margin. It is common to find symbiotic colonies of blue-green bacteria (usually Nostoc
Nostoc
Nostoc is a genus of cyanobacteria found in a variety of environmental niches that forms colonies composed of filaments of moniliform cells in a gelatinous sheath.The name "Nostoc" was invented by Paracelsus...
) growing among the cells. Under a microscope, the epidermal cells have trigones.
The sporophyte
Sporophyte
All land plants, and some algae, have life cycles in which a haploid gametophyte generation alternates with a diploid sporophyte, the generation of a plant or algae that has a double set of chromosomes. A multicellular sporophyte generation or phase is present in the life cycle of all land plants...
is erect when mature, growing up to 5 cm tall. Like other hornworts, its surface has stomata. The interior of the sporophyte differentiates into a central column and a surrounding mass of spore
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...
s and elater
Elater
An elater is a cell that is hygroscopic, and therefore will change shape in response to changes in moisture in the environment. Elaters come in a variety of forms, but are always associated with plant spores...
cells, with a distinct spiral. The spores are both green and relatively large with an ornamented surface.