|Copyright: Ungureanu Liviu (Apashu)
|Date Taken: 2010-06-04|
|Exposure: f/8, 1/500 seconds|
|More Photo Info: [view]|
|Photo Version: Original Version|
|Date Submitted: 2010-06-04 9:39|
|[Note Guidelines] Photographer's Note|
|The genus Ophrys is a large group of orchids from the alliance Orchis in the subtribe Orchidinae. There are many natural hybrids. The type species is Ophrys insectifera L.1753|
They are referred to as the "Bee orchids" due to the flowers of some species resemblance to the furry bodies of bees and other insects. Their scientific name Ophrys is the Greek word for "eyebrow", referring to the furry edges of the lips of several species.
Ophrys was first mentioned in the book "Natural History" by Pliny the Elder (23-79 AD).
They are terrestrial or ground orchids from central to South Europe, North Africa, Asia Minor, up to the Caucasus Mountains, but mostly in the Mediterranean region. They are considered the most important group of European terrestrial orchids.
During summer all Ophrys orchids are dormant as an underground bulbous tuber, which serves as a food reserve. In late summer/autumn they develop a rosette of leaves. Also a new tuber starts to grow and matures until the following spring; the old tuber slowly dies. The next spring the flowering stem starts to grow. During flowering the leaves already start to wither.
Most Ophrys orchids are dependent on symbiotic fungi. Because of this, some species only develop small alternate leaves. Transplanting specimens, especially wild specimens, is difficult, sometimes impossible, due to this symbiosis. The shiny, basal leaves have a green or bluish color. Two to twelve flowers grow on an erect stem with basal leaves.
Orchids of the genus Ophrys use sexual deception to attract pollinators to their flowers (Schiestl 2005). In sexual deception, an orchid attracts male pollinators by producing the sex pheromone of virgin female pollinators in addition to providing visual and tactile cues (Schiestl 2005; Schluter et al. 2009; Stokl et al. 2009). These signals stimulate mating behavior in the male pollinators, which then attempt copulation, called “pseudocopulation”, with the orchid labellum (Schluter et al. 2009). During pseudocopulation, pollen from the flower’s column becomes attached to some part of the pollinator, usually the head or abdomen, and the pollinator inadvertently carries and transfers this pollen to other flowers when they are once again enticed into pseudocopulation (Borg-Karlson 1990; Gogler et al. 2009; Stokl et al. 2009). While the morphological cues such as the shape and texture of the labellum play a role especially at close range in inducing the pollinator mating behavior, the orchid’s pheromone mimic, or allomone, has been shown to play the most important role in enticing the pollinators to the flower (Schiestl 2005; Schluter et al. 2009).
The allomone produced by an orchid is specific for its pollinator, of which it usually only has one (Ayasse et al. 2007; Gogler et al. 2009, Schluter et al. 2009) . The allomone is a mixture of alkenes and alkanes (Schiestl and Cozzolino 2008). There are one or more active species in this mixture that account for the attraction of pollinators (Vereeken and Schiestl 2008). Pollinators and orchids use the same chemical compounds in the same absolute amounts in their pheromones and allomones, respectively (Schiestl 2008).
The Bumblebee Orchid (Ophrys bombyliflora) is a typical example. It has flowers that look and smell so much like female bumblebees that males flying nearby are irresistibly drawn in by this chemical signal, stimulating them sexually. The insect gets so excited that he starts to copulate with the flower. The firmness, the smoothness and the velvety hairs of the lip are a further incentive for the insect to enter the flower. The pollinia inadvertently stick to the head or the abdomen of the male bumblebee. On visiting another orchid of the same species, the bumblebee pollinates its sticky stigma with the pollinia. The filaments of the pollinia have, during transport, taken such a position that the waxy pollen are able to stick to the stigma. Such is the refinement of the reproduction. If the filaments hadn’t taken the new position, the pollinia could not have pollinated the new orchid.
Every Ophrys orchid has its own pollinator insect and is completely dependent on this species for its survival. Furthermore, duped males are not likely to return. They even ignore other plants of the same species. Therefore, only about 10% of an Ophrys population gets pollinated. This is enough to preserve the population, since each Ophrys orchid produces about 12,000 minute seeds.
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