It is a truth universally acknowledged, that a wild flower in possession of a fortune in nectar and pollen, must be in want of a pollinator, Jane Austen might have written, had she been a botanist. All along this former railway line, on a sunny May morning, there are thousands of newly opened flowers laden with such inducements, vying for the attention of foraging bumblebees. And none delivers its pollen with such deception and violence as broom (Cytisus scoparius).
A Violent Explosion of Pollen
A large bumblebee arrives, settles briefly, finds no nectar and departs, leaving a deranged tangle of stamens protruding from the petals. What happened? Poking my finger into an intact flower, to mimic the visitor, there is an explosion of pollen as 10 stamens and a coiled stigma, confined in the boat-shaped keel petal, break free. Simultaneously, they deliver and collect pollen, with a gut-punch to the insect's furry abdomen. Bumblebees do not seem to mind; the trap has been tripped in almost every flower on this bush.
Gentle Precision of White Dead-Nettle
Nearby, white dead-nettle flowers (Lamium album) achieve the same ends with gentle precision. As I watch, a common carder bee settles on a landing platform, reaches deep into the throat of the flower for nectar, then leaves with a dab of white pollen on its thorax, applied by stamens hidden inside the flower's hooded standard petal. The visitors, exploited but rewarded, do not feel a thing, and deposit the pollen in the next flower, where a stigma inside the hood, fork-tipped like a serpent's tongue, collects the delivery.
The Dandelion's Free Lunch
What about the dandelions (Taraxacum officinale) in the grassy verge around my feet? Ubiquitous, prolific suppliers of easily accessible nectar and pollen, they are never in want of a pollinator but, from the plant's perspective, it is squandered wealth; dandelions are apomictic, always setting seeds without the need for fertilisation via a pollen grain. Bumblebees crawling over them, probing the inflorescences' florets for nectar, smothered with pollen, periodically pause to brush it from their eyes. In the dandelion's world, pollinators are redundant, but its largesse is the bumblebee's equivalent of an all-you-can-eat free lunch, an invaluable energy supply in spring. One of the universally acknowledged truths of natural history is that it often confounds assumptions and delivers endless surprises.
