Picea pungens is strictly
a cultivated species in Wisconsin. It does not escape from
cultivation and is found only where it has been planted.
It is included in the list of gymnosperms because it is
a very common horticultural species in Wisconsin and because
it (along with Pinus nigra, Pseudotsuga menziesii
and Taxus cuspidata) is a useful addition to the
small list of native species of gymnosperms, for teaching
purposes.
Picea pungens can be recognized
as a spruce by the sharp-pointed needles (1.6-3.0 cm long),
4- angled and nearly square in cross-section and attached
to woody projections of the twig known as sterigmata. It
lacks the hairy twigs of P. mariana and has much
longer cones than P. mariana. It can be distinguished
from the other spruces in Wisconsin by the unique cones
6-11 cm long, the wrinkled, papery scales with erose (irregularly,
toothed) tips. Leaves are often a pronounced blue-green,
but this is not a reliable key character in itself. There
are cultivars of P. pungens that are not blue-green
in color, and there are individuals of Picea glauca
for which the new growth is strongly blue green.
|
|