Pteridium aquilinum is a common and distinctive fern in
Wisconsin. The blades are 3-pinnate
(at least at the base), broadly triangular and are often held
more or less horizontally. Sori are borne along the margins
of the segments and are covered by the false
indusium (and a true indusium beneath the false). The blades
tend to be large and although they are spread out along a rhizome
they often form stands dense enough
to thoroughly shade the ground beneath. Four varieties of
this species are recognized, but only variety latiusculum
is present in Wisconsin.
Pteridium aquilinum var latiusculum ranges from
Newfoundland to Florida, west to Texas and southeastern Manitoba.
In Wisconsin it is common throughout the state in forest clearings,
barrens, pastures, roadsides and other uncanopied sites and persists
long after forest has reclaimed cleared areas. Extensive, robust
stands often develop after clear-cutting of trembling aspen. In
number of fronds produced it is probably the most numerous fern
in Wisconsin.
|
|