Biology Reference
In-Depth Information
Slime Molds
Slime molds belong to the Myxomycetes, a group
intermediate between bacteria and fungi. Their
assimilative phase is a plasmodium, which is
transformed into distinct fructifications on a
substratum. They are not parasitic and are often
found in rotting logs. Sometimes they are a nui-
sance in lawns, for the plasmodium after
ingesting decayed organic matter or microorgan-
isms for food moves up a grass blade for fruiting.
Their spores are produced on or in aerial
sporangia and are spread by wind. On absorbing
water the spore cracks open and the contents
escape as a swarmspore, sometimes two, with
two flagella. The swarmspore ingests food like
an amoeba, divides by fission into a myxamoeba,
unites with
multinucleate plasmodium. There are many spe-
cies. Two only are listed here, as being common
on turf.
Fuligo septica (formerly
Mucilago spongiosa
).
Cream to yellow plasmodium forms large grayish
white structures, 2 to 6 cm long by 1 to 6 cmwide,
that are lobed and branched sporangia filled with
a dark mass of purple, spiny spores.
Mucilago spongiosa (see
Fuligo septica
).
Physarum polycephalum Plasmodium color-
less, watery-white or yellow. Fruiting bodies
small, gray, sessile, crowded on grass blades,
and scattered in groups or rings over an area of
several feet. Spores are purple brown in mass.
The sporangia develop during humid weather in
summer and autumn. Use a stream of water to
wash the spore masses off the grass.
another
to
form a
zygote,
which enlarges, with mitotic division,
into a
