Peculiar plants: bird of paradise
We look at the South African strelitzia, or bird of paradise, whose flowers are pollinated by birds’ feet
THERE are many ways in which plants can be peculiar. Most of these are linked either with pollination, seed distribution, or with their mode of life and the conditions in which they live. Others have developed curious habits and organs, as occurs with the insectivorous plants.
Some species are extraordinarily large for no apparent reason; a few are renowned for the size or quantity or persistence of their seeds. Yet others have significance to mankind, or have mythological attributes given them. And, of course, there of many of which are visually odd in one way or another.
No other flower like strelitzia
My first example is certainly one of the latter: there is no other flower resembling the strelitzia, or bird of paradise flower. It also has the interest of being the only flower to be pollinated by birds’ feet.
Strelitzia is related to the banana family, Musaceae, and its leaves show a similarity to those of bananas. In
S. augusta the leaves are 2-4ft (60-90cm) long and 1-2ft (30-60cm) broad, on very large stems. The species usually seen is S. reginae, named, incidentally, after the wife of George III, Queen Charlotte Sophia, of the house of Mecklenburg-Strelitz.
The flowers are carried on a stiff, thick, 3ft (90cm) stem, which terminates in a rigid boat-shaped structure halfway between a spathe and a bract, carried at an angle to the stem. This is all that is visible in the bud stage. Then there emerge, one by one, extraordinary flowers with three large orange sepals, two of them erect, and a trio of blue horizontal petals, one insignificant and two long and narrow, which combine to form an arrow-shaped ‘tongue’. In the groove of this tongue, which itself fits into the boat-shape spathe, are the five long stamens and single threebranched style.
There are several flowers in the spathe and as each matures it tilts upwards, until finally a fan-shaped array of flowers is revealed. Birds visit the flowers to obtain the abundant nectar they produce. They grasp the stiff spathe with their feet and probe for nectar in the exposed flowers. The flower next in line to emerge transfers pollen to the bird’s feet, and when the bird visits another flower this pollen is transferred to the stigmas there.