The whispering of orchids

If orchids could speak what would they say?

Would they, exuding pheromones, sound like teenagers in heat, or other animals in must? Would they be fashion conscious, like humans, and speak of the latest insect fashions, and their own haute couture - matching this moth, or that wasp for attractive brilliance?

Almost certainly, one might think, because orchids when blooming are so often overwhelmingly beautiful, fragrant, and sexual – just like humans (and other creatures). The allure and behavioural ploys of orchids are very human in their deviousness – specifically, pretending to be something one is not, for sexual favours. However, although orchids regularly appear ‘dressed to kill’, their advances are only ever sexual and territorial. Unlike humans (and some other animals), their intents do not appear to be murderous, or malicious in other ways. But, in common with all species, they are very intent on reproduction, and towards that end they have become consummate manipulators of the desires of insects, and, it would seem, humans.

Orchids attract pollinators, like moths, bees and wasps by imitating their sexual displays – emitting pheromones and aromatic fragrances, and looking like the sexual parts of insects . . . and other animals. In the wild, insects are very obliging and pollinate their hosts with gay abandon. Humans are more measured in their orchid pollinating techniques, using spatulas and controlled environments to produce seeds, or the rougher means of mechanical division.

Nonetheless, of all plants, humans have a special bond with orchids – we seek them out in jungles, mountain meadows, and all manner of wild terrains, we rescue them from road works and careless developers, we cultivate them in hothouses, nurseries and gardens, we hybridise them, we form clubs and associations to worship them and better nurture them, we sell them from road side stalls and other localised arrangements, and we also sell them in a globalised, multi- billion dollar horticultural industry. There is something very instinctual in the love affair between humans and orchids. Eric Hansen’s book ‘Orchid Fever: A Horticultural Tale of Love, Lust and Lunacy’ (Methuen, 2001) was well titled. But this is very human centred. . . what would orchids say about all that?

Indeed, to go one step further, would orchids complain of global warming and extreme climate events?

The orchids in my collection appear to have become a little more erratic in their flowering times – either flowering early or not at all. But this is not scientifically viable data. I have recently moved them from a coastal to an inland foothills location - so they would be a little confused, wouldn’t they?

One recent British study found that climate change caused female (Andrena nigroaenea) bees to become sexually active too early for their partner orchids’ flowering. Male bees are then able to mate with female bees rather than being tricked by scent emitting (Ophrys sphegodes) spider orchids – ‘[f]or every 1 ºC rise in spring temperature, the peak flying dates of male and female bees occur 9.2 and 15.6 days earlier in the year but the orchid’s peak flowering advances by just 6.4 days.’ This increasing mismatch (modelled for the years between 1659 and 2014) threatens the ability of that orchid to be pollinated, and thereby threatens the continuing viability of the rare wild English population (see Neil Vowles, ‘New study shows climate change is wreaking havoc on delicate relationship between orchids and bees’, April 6, 2018, https://phys.org/news/2018-04-climate-wreaking-havoc-delicate-relationship.html ). Another recent study found that some kinds of orchids (holomycotrophic, or ‘terrestrial’, orchids) may be relatively tolerant to climate change (see Marta Kolanowska et. al. ‘Global warming not so harmful for all plants – response of holomycotrophic orchid species for the future climate change’, Scientific Reports 7, Article number: 12704 (2017) – available online). However, given that most orchids are epiphytes (that is, parasites, often growing on trees), this finding is limited in its relevance to all orchids – as the authors acknowledge. Here in Australia research by Lalita Simpson has found that our iconic rock orchid (Dendrobium speciosum) may become extinct in all but the Wet Tropics in Northern Australia (see Brendan Mounter and Sharon Molloy, ‘Climate change threatens Australia’s rock orchid. . .’ https://www.abc.net.au/news/2017-10-31).

So far there does not appear to be a large number of scientific studies of the subject of climate change and orchid behaviour – which does not mean that there isn’t a huge ecological problem looming. For instance, in London the Natural History Museum have set up a project aimed at ‘citizen science’ so enthusiasts can record their observations about the response of native orchids to environmental change. The global need for field research findings about orchids, and all other threatened species, has never been greater.

Surprisingly perhaps, my informal questioning of members of orchid societies finds a fair degree of doubt about the relationship between the flowering times of orchids and climate change. One might hypothesise that the average age of society members is high enough to predispose them towards climate change scepticism – admittedly an untested hypothesis.

But back to the sensory perception of orchids. . . of course orchids don’t have speech organs, or eyes, ears, and other human sensory organs and perceptions, or a humanoid brain. But that doesn’t mean they don’t have sensing abilities, or intelligence, or communicative ability. My orchids are definitely communicative. They tell me when they’re thirsty or hungry, or when they want to be moved. They like to be noticed when they’re flowering, but otherwise are quite reserved. One can always be surprised to notice a new shoot, or leaf, or flower spike. Like children, they need some looking after, but generally they are much more forgiving than humans. Sometimes, however, they get so upset they just die.

On balance however, a relationship with an orchid, has a lot to offer – beauty, seduction, and companionship in exchange for nurture. Perhaps that is why they so strongly appeal to ageing men and women. And maybe orchids will need special care in the future to avoid extinctions. Orchids show signs of being pretty smart - after all, they’ve been around a lot longer than humans.

Tom Jagtenberg