Osgoldcross Photography
Orchid
Last Tuesday I visited the nursery at my local park for the first time this year.
They were preparing the gardens for the 2010 season and in the heated houses I found this beautiful Orchid that was just begging to be photographed.
Orchidaceae are well known for the many structural variations in their flowers.
Some orchids have single flowers but most have a racemose inflorescence, sometimes with a large number of flowers. The flowering stem can be basal, that is produced from the base of the tuber, like in Cymbidium, apical, meaning it grows from the apex of the main stem, like in Cattleya, or axillary, from the leaf axil, as in Vanda.
As an apomorphy of the clade, orchid flowers are primitively zygomorphic (bilaterally symmetrical), although in some genera like Mormodes, Ludisia, Macodes this kind of symmetry may be difficult to notice.
The orchid flower, like most flowers of monocots has two whorls of sterile elements. The outer whorl has three sepals and the inner whorl has three petals. The sepals are usually very similar to the petals (and thus called tepals,), but may be completely distinct.
The upper medial petal, called the labellum or lip,, is always modified and enlarged. The inferior ovary or the pedicel usually rotates 180 degrees, so that the labellum, goes on the lower part of the flower, thus becoming suitable to form a platform for pollinators. This characteristic, called resupination occurs primitively in the family and is considered apomorphic (the torsion of the ovary is very evident from the picture). Some orchids have secondarily lost this resupination, e. g. Zygopetalum and Epidendrum secundum.
The normal form of the sepals can be found in Cattleya, where they form a triangle. In Paphiopedilum (Venus slippers) the lower two sepals are fused together into a synsepal, while the lip has taken the form of a slipper. In Masdevallia all the sepals are fused.
Orchid
Last Tuesday I visited the nursery at my local park for the first time this year.
They were preparing the gardens for the 2010 season and in the heated houses I found this beautiful Orchid that was just begging to be photographed.
Orchidaceae are well known for the many structural variations in their flowers.
Some orchids have single flowers but most have a racemose inflorescence, sometimes with a large number of flowers. The flowering stem can be basal, that is produced from the base of the tuber, like in Cymbidium, apical, meaning it grows from the apex of the main stem, like in Cattleya, or axillary, from the leaf axil, as in Vanda.
As an apomorphy of the clade, orchid flowers are primitively zygomorphic (bilaterally symmetrical), although in some genera like Mormodes, Ludisia, Macodes this kind of symmetry may be difficult to notice.
The orchid flower, like most flowers of monocots has two whorls of sterile elements. The outer whorl has three sepals and the inner whorl has three petals. The sepals are usually very similar to the petals (and thus called tepals,), but may be completely distinct.
The upper medial petal, called the labellum or lip,, is always modified and enlarged. The inferior ovary or the pedicel usually rotates 180 degrees, so that the labellum, goes on the lower part of the flower, thus becoming suitable to form a platform for pollinators. This characteristic, called resupination occurs primitively in the family and is considered apomorphic (the torsion of the ovary is very evident from the picture). Some orchids have secondarily lost this resupination, e. g. Zygopetalum and Epidendrum secundum.
The normal form of the sepals can be found in Cattleya, where they form a triangle. In Paphiopedilum (Venus slippers) the lower two sepals are fused together into a synsepal, while the lip has taken the form of a slipper. In Masdevallia all the sepals are fused.