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Species of the Week
Number 9 -- July 31, 2006
In the Species of the Week feature of the Wildwood Web we took a close look
at one of the species that lives in Wildwood. To see the earlier featured species check the Species
of the Week archives.
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Cup Plant
Silphium perfoliatum
Cup plant is native to this area, but it really
doesn't belong in the park. It was introduced into the
northernmost butterfly meadow when Pathways for Radford was creating
the meadows. Fortunately, or unfortunately, depending on your
opinion of introducing this plant, it is doing very well in the
butterfly meadow.
Cup plant is a big plant, it grows about 6 to 7 feet
tall and has big, triangular leaves. The leaves are in pairs,
and the two leaves of each pair are fused together around the stem,
forming a cup that can catch and hold rainwater. The cup is
visible between the leaves in the picture at left. Birds and insects
can drink the water, and carnivorous insects will hang out around
this watering hole waiting for prey to come to drink. I do not
know if anyone has tested whether the plant can tap into the water
as well, but it seems unlikely since the plant does not favor dry
habitats. |
Like several other Species of the Week we have met, cup
plant is a Composite, a member of the Sunflower Family, Asteraceae.
Like most composites it has both ray flowers and disc
flowers in its abundant flower heads. Each head has many
spreading yellow ray flowers. The disc flowers in the center disc are
also yellow, but the disc from which they grow is greenish brown.
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Cup plant likes wet prairies, open forests and river
bottoms, which explains why it seems so happy in the butterfly
meadow which lies in the floodplain of Connelly's run. It can
be found from New Hampshire to Ontario to North Dakota, south to
Texas, Mississippi, Alabama and North Carolina. There are a
mere 12 species in the genus Silphium,
all of them in the eastern and southern United States, with some
ranging into eastern Canada.
There are two variations on the cup plant, which have been
separated by some botanists into separate species, but are considered
varieties by most botanists. The most common version, found throughout
the range given above, tends to have leaves that narrow where the come
together, forming deep cups. It also has stems with few or no hairs.
The rarer version is found only in the New River Valley of North Carolina,
Virginia and West Virginia. This variety has hairy stems and the
leaves do not narrow as they come together, forming more of a flat plate to
shallow bowl than a cup.
The species name, perfoliata, means "through the
leaves," and refers to the stem coming up through the fused pair of
leaves. The genus name, comes from the Greek word silphion,
which refers to a plant of Northern Africa that produces a resin.
Silphion plants are apparently shown on the ancient coins of the Greek
city of Cyrene in what is now eastern Libya in northern Africa.
However, there seems to be no connection, other than their names, between
plants of the genus Silphium and the Silphion plants of north
Africa.
Look for the cup plant in the northern butterfly meadow; they
are in bloom now and hard to miss.
GGC |
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