OF THE WEEK
Dr. T. Ombrello - UCC Biology Department
While this species does not have a common name, members of the orchid genus Oncidium
are often referred to as Dancing Ladies or Dancing Dolls because the long sprays
of flowers resemble groups of ballet dancers. They are also called Butterfly Orchids because of the floral
resemblance to the colorful insects and
their tendency to flutter in a breeze.
Many people wonder why orchids are usually called by their scientific names instead of common names. The reason is simply that few have been either known or cultivated long enough to have acquired common English names. Orchids have been important in horticulture for little more than a century, and only have become widely available in the last 50 years or so. Forty percent of all orchids have no names whatever in their native lands, and that figure rises to about 90% when they are exported to foreign regions. In time, many will probably be given simple common names.
Scientific name: Oncidium sphacelatum
Explanation of scientific name:
from the Greek for swelling or tubercle, alluding to the crest on the lip of the
- dead, withered, diseased. To the
Meso-American Indians, the sunny yellow flowers streaked with stripes of dark
reddish-brown signified human blood reviving
the sun in time of danger. This
species, along with its close relatives, has long been associated with the dead
by the native peoples of Central and South America, and probably had some
intimate connection with some forgotten Toltec or Mayan funeral ceremony.
is one of over 750 species in the genus Oncidium,
and is a member of the large Orchid family (Orchidaceae).
are native to the western hemisphere, and this particular species naturally
ranges from Mexico to Honduras. Oncidium sphacelatum
is a prolific epiphyte. It grows on
other plants, such as in the crotches of tree limbs, but does not derive
nutrition from or harm its host in any way.
The plant consists of elongated and flattened storage stems (pseudobulbs)
clustered together with several leaves on each.
The roots are designed to cling to the substrate upon which the plant is
growing. The species blooms in the
spring, producing long (up to 5 feet) stalks bearing many flowers. This species displays the most prevalent flower colors found
in the genus Oncidium:
yellow, spotted and barred with reddish-brown.
Orchids have an amazing
array of flower shapes and sizes and have evolved interesting mechanisms for
pollination. Some orchids ensure
fertilization by means that are so bizarre as to be hardly believable.
All orchid flowers, however, have the same basic parts.
The flowers have 3 sepals and 3 petals, although some of these parts may
be fused or greatly reduced in size. One
of the petals (the lip or labellum) is different in that it is often larger and
showier. Projecting from the center
of the flower is the fleshy club shaped column, which is a fusion of male and
female reproductive organs. The top
of the column is the male anther with its pollen grains grouped in masses called
pollinia. Below the anther is the
female stigma, a sticky surface on which the pollinia are deposited during
pollination. Below the stigma is
the ovary, which expands into a seed capsule (fruit) after fertilization.