The bee’s knees

Story & Pictures: Andrea Abbott

You’ll almost certainly have seen this straggly, indigenous plant waving to you from roadsides, disturbed areas, grasslands, and, sometimes, gardens. Many people consider it a weed despite its fancy-sounding proper name, Gomphocarpus physocarpus, a mouthful that’s best pronounced when one is sober, and certainly not when under the influence of another well-known and more popular weed. Much easier to get your tongue around is its common but less flattering name, Hairy Balls, which could be the name of a Punk Rock band but is a reference to the plant’s spiky/hairy, inflated fruit sacs. There’s another, rather rude nickname for it but I won’t repeat it in the refined company of Chronicle readers.

Flowers of note

What I will say unashamedly though is that I am a Hairy Balls fan, and I’m here to defend its reputation. You see, far from being a pesky weed, Gomphocarpus physocarpus is not your run-of-the-mill plant and, in many respects, it’s the bee’s knees. It produces exquisite flowers and has an unusual pollination mechanism. Next time you encounter one in flower, look closely at those blooms and you’ll see how out-of-the-ordinary and complex they are. They dangle like dainty pendulums, their white petals bending backwards as if to cast a protective shield over the bit that really matters. That bit is the corona, which is in the centre of the flower and comprises five pinkish or purplish pouched lobes. The corona surrounds the stamens – i.e. the male part – and the carpels  –  the female bits, which I won’t describe in detail for fear of launching into a biology lesson.

Packages of pollen

What’s important to know for this discussion is that instead of a dusting of loose pollen, which is the way anthers of most flowering plants present the male gametes, the non-conformist Hairy Balls produces waxy masses of cohering pollen grains called pollinia that sit inside stigmatic slits between the flower lobes, where they wait for helping legs to liberate them. (In case that isn’t impressive enough, Orchids also produce pollinia which puts G. physocarpus in splendid company.)

Dining at the Hairy Balls Cafe

The helping legs are those of pollinators, especially bees and wasps enticed by the heady nectar that drips abundantly from the flowers. As those pollinators wine and dine and dance from flower to flower their legs might slide into the stigmatic slits, where they get attached to the pollinia.  So, up to their knees in pollinia, the insects move on to the buffet at the next Hairy Balls nectary, where the process repeats, except this time the pollinium is deposited. Which goes to show there’s no such thing as a free lunch. 

Unshackling the workers

Indeed, this particular lunch is often fraught with peril. Sometimes, pollinators struggle in vain to pull their loaded limbs out of the stigmatic slits and end up shackled to the flower. Previously, when I saw bees and wasps dangling from the flowers as if in drunken defeat, I assumed they’d gorged themselves on the nectar and that it had glued them to the spot. Sort of dying in the line of duty. Now I know to use a twig or leaf to gently give those important little workers a leg-up and thus help them to continue on their vital mission. This simple task I consider an almost sacred duty in this catastrophic era of insect extinction when every insect’s life matters.  What’s more, in the case of G. physocarpus it’s essential the pollinia are deposited in other Hairy Balls individuals because the plant is self-incompatible, meaning it can’t set seed from its own pollen.  No incest in this species!

The life and times of milkweeds, monarchs, and plain tigers

Bees and wasps aside, certain butterflies also have a symbiotic relationship with G. physocarpus. A member of the Milkweed or, to use the correct name, Asclepiadiacea family, it’s a host to the Monarch butterfly. You’ll have heard of the great migration of Monarch butterflies in North America and the concerns around the reduction of their habitat along parts of their route, where Milkweeds fall victim to industrial scale monoculture of crops like soybeans and corn. This is, though, a controversial issue that needs further research.

Getting back to our own species of Monarch, now called the African Plain Tiger, in its time as a crawling caterpillar (how tempting it is to go with the feline theme and refer to tigerpillars,) it feeds on the leaves of G physocarpus and, as a free-flying adult, sips the flowers’ nectar. Like the other pollinators that frequent the Hairy Balls pantry, the butterflies often pay their way when, up to their knees in pollen, they deliver the pollinia to the next G physocarpus on their flight path.

A need for weeds

And so the life cycle continues, plants and their attendant insects working in perfect sync to ensure the future of their species, and by extension the human species as well. For, as we rather belatedly have come to know, an absence of pollinators threatens food security. This stark truth is something to bear in mind next time we dismiss an indigenous plant as being an unsightly pest. It could so easily be a host to a suite of essential workers.

Weeds matter too.

_{Disclaimer:  This is a non-botanist’s sometimes irreverent but nevertheless admiring view of flora and their relationship with attendant fauna. For a more scientific explanation visit SANBI}