quadrifidum Pers. Rayed Earthstar or Four-footed Earthstar,
neulasmaatähti tai neliliuskamaatähti, fyrflikig jordstjärna.
Siikainen, Otamo (St) 28.4.2013 and 12.5.2013.
Here (img 5) the Rayed Earthstar (Geastrum quadrifidum) grows in
a not so typical open environment with birch trees. A more typical
habitat is old spruce forests - a habitat it shares with G. pectinatum
(Imgs). Both habitats are
however in the vicinity of the Otamo dolomite quarry and apparently
characterized by chalk-rich soils.
about 70 on 6 square meters; obviously from last autumn (2012) or
some of them even older.
(diameter of rays): (<1) - 1 - 2 - 3 - (4) cm
Rays: 4-5 - equally common
The mycelia forms a cup concealed in debris under the rays wich
are attached solely by their tips to the mycelial cup in the substratum
(Img 4). This feature clearly distinguishes the Rayed Earthstar
from the rarer G. minimum ( rays > 4, usually 6-8) and G. schmidelii
(rays 5-8), which are attached to the mycelia all over the underside
of their rays and thus adhering dirt and debris. G. minimum and
G. schmidelii, though very rare in Finland, are species which possibly
might be expected to occur in this location.
The old earthstars of the last autumn with the remaining papery
thin sclerenchymatous layer are now in spring chalk white contrasting
to the dark spore cases (Img 1-3).
The circular spore cases had short slender stalks (pedicels) and
always had a distinct smooth ring-like apophysis above the pedicel
(Img). The Rayed Earthstars
had a conical mouth-zone, called the peristome, which is fibrillose
(fimbriate) (Img 2-3), but not grooved as for instance G. schmidelii
and G. pectinatum. The peristome
is very distinctly delimited. The G. fimbriatum ( rays 5-8) does
not have a pedicel or an apophysis and the peristome is not distinctly
delimited. G. fimbriatum is not as rare as G. quadrifidum in the
above type of habitat.
©2013 Staffan Storteir