Geastrum leptospermum
Encyclopedia
Geastrum leptospermum is a species of fungus
in the Geastraceae
family. It was first described
scientifically by American mycologist George F. Atkinson in 1903. The fungus produces small fruit bodies
and grows in mosses on tree trunks.
, or spore sac, is nearly spherical, 2.5 – thick, pale gray to pale tan
in color, and dusted with fine whitish particles that also cover the inner surface of the freshly opened rays. The mouth on the apex of the peridium is very small, minutely fibrous, and surrounded by a conical, white disc which is distinctly outlined and radially fibrous (if not deeply grooved). As the fruit body matures, the fibrous layer of the outer peridium splits, star-like, into three to six rays about half way down or more. The fungus is fornicate, meaning that the rays curve downward so that the base of the fruit body becomes arched up, which elevates the spore sac. This leaves its delicate fibrous, mycelial
layer as a distinct, membranous, white cup on the underside, with its margin also rayed by slits, the rays attached to the rays of the plant above. When freshly opened, the inner surface of the rays is covered with a fleshy, pale buff, layer of tissue. This layer, when dry, forms the thin, tan or light brown, smooth and nearly complete membrane over the fibrous layer. The underside of the rays is white and smooth. There is no obvious columella (sterile tissue in the base of the gleba that extends into the gleba).
The spore
s are spherical and measure 2–3 μm
. Under high power microscopy they appear as having a surface that is roughened by many small points or warts. The capillitium (coarse, thick-walled cells in the gleba) threads are unbranched, and measure about 3 μm thick. Both the spores and the capillitium are whitish to very pale yellow-brown.
Fungus
A fungus is a member of a large group of eukaryotic organisms that includes microorganisms such as yeasts and molds , as well as the more familiar mushrooms. These organisms are classified as a kingdom, Fungi, which is separate from plants, animals, and bacteria...
in the Geastraceae
Geastraceae
The earthstars are the family Geastraceae of gasterocarpic basidiomycetes . It includes the genera Geastrum and Myriostoma. About sixty-four species are classified in this family, divided among eight genera....
family. It was first described
Species description
A species description or type description is a formal description of a newly discovered species, usually in the form of a scientific paper. Its purpose is to give a clear description of a new species of organism and explain how it differs from species which have been described previously, or are...
scientifically by American mycologist George F. Atkinson in 1903. The fungus produces small fruit bodies
Sporocarp (fungi)
In fungi, the sporocarp is a multicellular structure on which spore-producing structures, such as basidia or asci, are borne...
and grows in mosses on tree trunks.
Description
The inner peridiumPeridium
The peridium is the protective layer that encloses a mass of spores in fungi. This outer covering is a distinctive feature of the Gasteromycetes.-Description:...
, or spore sac, is nearly spherical, 2.5 – thick, pale gray to pale tan
Tan (color)
Tan is a pale whiteish, tawny shade of white. The name is derived from tannum used in the tanning of leather.The first recorded use of tan as a shade name in English was in the year 1590....
in color, and dusted with fine whitish particles that also cover the inner surface of the freshly opened rays. The mouth on the apex of the peridium is very small, minutely fibrous, and surrounded by a conical, white disc which is distinctly outlined and radially fibrous (if not deeply grooved). As the fruit body matures, the fibrous layer of the outer peridium splits, star-like, into three to six rays about half way down or more. The fungus is fornicate, meaning that the rays curve downward so that the base of the fruit body becomes arched up, which elevates the spore sac. This leaves its delicate fibrous, mycelial
Mycelium
thumb|right|Fungal myceliaMycelium is the vegetative part of a fungus, consisting of a mass of branching, thread-like hyphae. The mass of hyphae is sometimes called shiro, especially within the fairy ring fungi. Fungal colonies composed of mycelia are found in soil and on or within many other...
layer as a distinct, membranous, white cup on the underside, with its margin also rayed by slits, the rays attached to the rays of the plant above. When freshly opened, the inner surface of the rays is covered with a fleshy, pale buff, layer of tissue. This layer, when dry, forms the thin, tan or light brown, smooth and nearly complete membrane over the fibrous layer. The underside of the rays is white and smooth. There is no obvious columella (sterile tissue in the base of the gleba that extends into the gleba).
The 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 are spherical and measure 2–3 μm
Micrometre
A micrometer , is by definition 1×10-6 of a meter .In plain English, it means one-millionth of a meter . Its unit symbol in the International System of Units is μm...
. Under high power microscopy they appear as having a surface that is roughened by many small points or warts. The capillitium (coarse, thick-walled cells in the gleba) threads are unbranched, and measure about 3 μm thick. Both the spores and the capillitium are whitish to very pale yellow-brown.