When each of the many (more than 2) flower pedicelsarises from around the same point at the tip of its peduncle, it is termed umbel arrangement. This arrangement is often compared to that of the struts (ribs/frame) of an umbrella.
Many of the species in genera Bulbophyllum are examples of this unique characteristic. Flowers in umbels are referred to as umbellate, or occasionally subumbellate (when flowers are almost umbellate).
A modified leaf considered a part of the flower is termed floral bract. The purpose of it is to support or enfold the flower, however in the case of orchid flowers it rarely enfold the flower.
Floral bracts arise from the rachis at the point of contact of the pedicel. It can be a minute triangular-like growth to a leaf-like even longer than the pedicel or the pedicellate ovary. In some species it is larger than the flower and forms a concave shape. The many characteristics of floral bracts like its length, deflexed, hairy, colours, encircling the ovary, deciduous at flowering etc., help in identifying the species.
Orchid fruits are in the form of a capsule or a pod, carrying thousands and thousands of dust-like seeds. Fruits are of different shapes and sizes, from a minute globose or berry like capsule to a long cylindrical pod. Fruits attain erect, sub-erect or pendulous arrangement. In some genera the pedicel elongates considerably while the fruit matures. On maturing, fruits burst open laterally by 3 or 6 slits and the minuscule sized seeds get dispersed with the help of air flow.
Many orchid fruits have interesting characteristics to observe and study. Some attain shapes that of sausages or are three-angled; in a few cases the outer surface of the capsule or pod is pubescent (with soft hairs); they are either 3 or 6 ribbed; some are with a unique beak at its apex; in a few genera the fruits mature rapidly while in others it take months; its colour varying from green to brown or brick red, even with unique purple spots and patterns.
Pseudobulbs of a few orchid species in genera Pleione and Porpax got a unique sheath covering. As the bulb matures, the sheath partially disintegrates to form a fine fibrous radiating set of veins either forming a net-like pattern or longitudinally converging. This characteristic helps in identifying the species while they are not in bloom or leaf-less.
Spur is not an uncommon characteristic in orchid flowers. It is defined as the hollow slender extension from the base of the lip. The purpose of the spur is to hold nectar and it varies in shape and size, solitary across all genera. However, very rarely a few orchid genera flowers possess 2-spurs.
Presented here is a Satyrium sp. and its Alba form.
A bristle-like extension, at the apex (tip) of leaves, floral bracts, sepals and petals is termed an awn. This characteristic is very prominent in the Poaceae (Grass) family, however, many orchid plants also have this unique feature.
The general perception about orchid flowers is that of large flowers with spread open bilaterally symmetric sepals and petals. However, there are many orchid flowers that are tubular in characteristic. With either sepals or sepals and petals fused to form a tube like structure with only its apical ends free.
Botanically the process of fusion of like/similar parts is termed connation, and those fused parts are described as connate.
While I was in the 6th class, our Biology teacher demonstrated an experiment to help us understand the way in which water is transported in a plant, with the help of Balsam plants and coloured water. A Balsam plant is placed in a beaker filled with coloured water. After some time we saw the coloured water slowly rising up the stem. She further explained that the Balsam plants are particularly used because they have translucent stems, so that we can see the coloured water moving up the stem. Hence, whenever I think about the word “translucent”, I remember those Balsam plants.
However, it is not just the Balsam plants that have translucent characteristics, a few orchids also have this unique characteristic, even though the phenomenon is very rare.
Presented here is Pholidota protracta Hook.f., with its translucent pseudobulb.
Orchid leaves are generally green in colour, with parallel veins converging to both ends. However, a few of the ground orchids (also rarely some epiphytic ones) bore green to brown or reddish-brown mottled (with irregular marks, blotches or patches), variegated (with zones of different shades of colour) and reticulated (with net like veins) leaves. Due to their beautiful leaf colouration and vein patterns, these orchids are called “Jewel Orchids”. Many species from the genera Anoectochilus, Corybas, Goodyera, Neottia, Paphiopedilum, Zeuxine etc., are examples of “Jewel Orchids”, with astonishingly beautiful leaves. These orchids with their attractive leaves are very decorative even when not in flower, hence is of great demand among orchid growers and enthusiasts across the globe.