Orchid Lessons by Naresh Swami – Page 4 – Naresh Swami | The Orchids of the Sikkim Himalaya

Orchid Lessons by Naresh Swami – Pollination in orchid flowers.

In orchid flowers, the basal part of the lip is often lobed, curved up to form a narrow structure with the column running along its open upper side. The apex part of the lip plays the role of a landing pad where the pollinator lands. The odour of the flower, the presence of pseudopollen, or the nectary glands make the pollinator crawl further inside. The anther cap is attached in such a way that it allows the pollinator to move forward without any obstruction. As the pollinator forces its way back, the pollinarium gets attached to the thorax of the pollinator and carried away.

(Note: Explained here is one of the several methods of the process of pollination in orchids.)

Post 21 – 21/October/2020

Orchid Lessons by Naresh Swami – Ants, the guardians of orchid flowers.

Ants are not known pollinators of any orchids. However, ants and orchids keep a mutually beneficial relationship – a complicated process least studied in the eastern Himalaya.

It has been recorded during my work that certain species of orchid flowers attract ants even before they open. The presence of ants scare away many insects that damage or fully destroy buds and flowers while they hunt for nectar, thus affecting the process of pollination and seed production.

As flowers play a critical role in the survival of many species, orchid plants developed the system by which they attract certain species of ants with their nectar and in-turn the ants help in protecting the flowers from many damage causing insects.

It is interesting to note that those insects that cause no damage to buds and flowers are not being attacked by ants. Indeed these friendly insects are mostly pollinators of these species.

Post 20 – 18/October/2020

Orchid Lessons by Naresh Swami – Bilobed spur.

The apex (point away from its attachment) of the spur is generally pointed, round, obtuse, or rarely truncated. However, few orchid flowers produce spurs with its apex bilobed (also referred to as 2-lobed).

The reasons that make the apex of the spur unique is a topic least researched. However, it has to be believed that this characteristic is related to certain pollinator behaviour.

Post 19 – 15/October/2020

Orchid Lessons by Naresh Swami – Superior lip.

When the attachment of the lip is above the points of attachment of other floral whorls or parts (sepals and petals) that type of lip is termed as a superior lip.

This is a rare characteristic in orchids, only a few genera produce superior lipped orchid flowers.

Post 18 – 12/October/2020

Orchid Lessons by Naresh Swami – Hairy orchid plants.

Generally orchids are glabrous (smooth and hairless) plants. However, hairy characteristics in orchids are not uncommon, it can be very minute to a cm long, soft to stiff, silky to shiny etc., on stem, raceme, leaf, flower parts etc. What may be, all types of hairy outgrowths are whitish.

Rarely few orchid species are with brownish hairs. It is a characteristic seen only in a few genera.

Post 17 – 09/October/2020

Orchid Lessons by Naresh Swami – Twisting of flower pedicel in orchid flowers.

In resupinate orchid flowers, when buds are formed they are upside down – meaning the lip and spur (if present) are on top side of the bud. As the buds develop, the pedicel twists either clockwise or anti-clockwise to invert the bud, thus arranging the lip and spur to the bottom side of the flower. This arrangement helps visiting pollinators.

(Note: Pics of spurred buds are used to make the lesson more easier).

Post 16 – 01/October/2020

Orchid Lessons by Naresh Swami – Perpendicularly bent spur.

Spur is the hollow slender extension from the base of the lip. Its length and size varies from species to species. It can be a minute globose to a few cm long cylindrical structure. Spurs are often straight, pendulous or slightly curved toward its apex in arrangement.

However, a few species in genera Aerides produce uncommon perpendicularly bent triangular shaped spurs.

Post 15 – 28/September/2020

Orchid Lessons by Naresh Swami – Distichous flower arrangement.

When flowers arise in two opposite vertical rows on either side of the axil, the arrangement is termed distichous flower arrangement. The arrangement can be alternate or opposite.

This type of arrangement is not confined to flowers, many orchid species produce distichous leaves also.

Post 14 – 25/September/2020

Secund flower arrangement.

When all flowers bore on sides of the axil are turned to one direction, the arrangement is termed secund flower arrangement. Probably due to its rarity in the family of orchids, a few orchid species are even named after this flower arrangement with specific names or epithets like secunda, secundum, secundus, secundiflora, secundiflorus, etc.

Many observations during my field trips have opened a new dimension in the study of pollinator behaviours with respect to secund orchid flowers.

Post 13 – 22/September/2020

Orchid Lessons by Naresh Swami – Umbel flower arrangement.

When each of the many (more than 2) flower pedicels arises 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).

Post 12 – 19/September/2020