Say it with flowers

14 February 2014 by Malcolm Campbell, posted in Biology, Evolution, Science

Send her your love, with a dozen roses. Make sure that she knows it, with a flower from your heart.” From Send One Your Love by Stevie Wonder (1950- )

It is a day for flowers.

On Valentine’s Day, in the western world, human passion for flowers is in full bloom. According to the Retail Advertising and Marketing Association, in 2013, in the United States, fully one-quarter of the adult population purchased flowers on Valentine’s Day. They were provided with provided 196 million cut roses alone, served to them by almost 124000 people, employed by approximately 25000 florists. The overall sales of cut flowers, prepared just within the United States, topped $400 million on Valentine's Day in 2013. Of the flowers purchased, between two-thirds and three-quarters were purchased by men. This year is likely to look little different. The same sort of scale of floral gifts can be found on Valentine’s Day for many western countries. All so that people could proclaim or affirm their love for another. flowers3

How did we come to use flowers as a declaration of romantic love?

The gift of flowers on Valentine’s Day can be traced back to England in the 18th century. Originally, Valentine’s Day was an observance within Christian religions, paying homage to the martyr, St. Valentine. From around the time of Geoffrey Chaucer, in the 14th century, Valentine’s Day became associated with romantic love. In the courtship rituals of that time, notes proclaiming love were exchanged. This tradition continued to present day, with the presentation of gifts, like flowers, being incorporated in the intervening years.

This provides a historical perspective on the emergence of flowers as a Valentine’s Day gift, but it doesn’t really address the question of why flowers would be deemed a suitable romantic gift in the first place. Why do we gift flowers? Why not fruit? Or leaves? What is it about flowers that makes them appropriate for this purpose?

To put an even finer point on it, is the use of flowers to proclaim romantic interest rooted in our evolutionary past?

There are compelling reasons to think that it is.

If nothing else, flowers can be powerful signifiers of an outcome of romance – of sex. Flowers are not merely emblematic of sex, but they are the staging ground for plant sex, plain and simple.

Flowers contain, of course, the reproductive tissues of plants. Generally, at least one sex is visible in a flower – either the pollen-producing “male” organs, or the pollen-receiving, seed-producing “female” organs. Frequently, both sexes are visible in the same flower.

Flowers lay plant sex out there in all its glory. flowers1a

Many flowers have evolved so that they can attract other species - animal species - to help them engage in sex. In keeping with this, many flowers have evolved the capacity to synthesise remarkable pigments, from those that we can see with visible light, like reds, yellows and purples, to those that can only be seen under ultraviolet light, for the purpose of attracting pollinators. Similarly, different floral shapes have evolved to accommodate specific pollinators. In keeping with this, pollinators, like bees, hummingbirds and bats, are attracted to specific floral pigments and flower morphologies. They are attracted to these pigments and shapes because they signify a reward for the pollinator – frequently a nutrient-rich nectar. The attracting colour and nectar reward work well for the plants – they attract pollinators that then pick up the pollen and pass it to another plant – pollinating it in the process.

In some cases, flowers have very pronounced reproductive organs – with prominent, phallic, pollen-producing tissue for example. These also serve as attractants for pollinators, consuming a portion of the pollen for their own purposes, but passing enough from plant to plant to ensure fertilisation.

Some plants have gone one step further. They have evolved floral tissues that actually resemble the pollinators themselves. Some orchids, for example, have floral tissues that resemble insect pollinators. Pollinators are attracted to these tissues because they look like a prospective mate. Their courtship, and attempts to procreate with the floral tissues function to help the plant reproduce – they hijack their pollinators reproductive drive to reproduce themselves.

As such, flowers are not merely metaphors for sex, they are sex.

As a species, we have a remarkable capacity for symbolic logic. We are able to draw conclusions from abstractions. In our evolutionary past gift of flowers may have played to this trait. flowers6

Far from being an abstraction, flowers can be a pretty clear and simple evocation of sex. If anything, flowers lack in subtly when it comes to conveying a message of romance. They are nature’s equivalent of writing the word “sex” on a piece of paper.

This said, it may be that the message contained within the gift of flowers was more nuanced than that. After all, not all flowers lay their sex organs bare to deliver a lusty message. Roses, for example, robe their reproductive tissues in lush petals, hiding them from prying eyes.

Roses suggest that floral gifts may convey a less overt message than merely “sex”.

Flowers, of course, presage the location of fruits and seeds. Roses, for example, foretell of the impending rosehip. In or evolutionary past, individuals who were able to identify the sites of flowers now, knew where there would be food resources in the future. What’s more, flowers themselves can be a food resource in and of themselves. Flowers can be rich in both nutrients and plant-produced chemicals that have nutritional or medicinal benefits. This said, plants generally also provide fairly strong deterrents for the consumption of their reproductive organs before they have, in fact, reproduced. Either way, even if they are not a food resource themselves, flowers can be a means for an individual to show that they will, in future, be a resource provider.

There are plenty of examples of animals that provide a gift that provides an indicator of whether they will be a good provider. Such a gift is known as a nuptial gift. Many insects and spiders present a nuptial gift to prospective mates, as a pre-requisite to mating. Some birds have taken nuptial gifts to a remarkable extreme. The male shrike, a relative of songbirds that acts like a raptor, will festoon thickets with the carcasses of prey to attract a mate. The male bowerbird, on the other hand, assembles an elaborate structure that they decorate with sticks and brightly coloured objects in an attempt to attract a mate.

Notably, humans appear to be the only primate species that uses flowers as a nuptial gift. If flowers were a good signifier of being a better provider, it would be surprising that another primate species didn’t use flowers to convey this fact. This said, perhaps the community and family structures of other primate species don’t require this sort of indicator. Indication of being a good provider may be more useful for largely monogamous, pair-bonded species like humans.

Another intriguing possibility is that flowers, inadvertently, are evocative of something less tangible. flowers2

Floral colours and scents are frequently similar to fruit hues and odours. It has been hypothesised that our trichromatic vision and components of our sense of smell evolved, such that we are positively stimulated by fruit colours and odours.

Our love of flowers may stem from our love of fruit. That is, our gifts of flowers emerged merely as proxies for gifts of fruit. Apes will gift fruit to each other, so perhaps our floral gifts are an extension of such gifting. This said, if it is the case that flowers are a proxy for fruit, why not gift fruit? The answer may be that flowers actually are evocative – a proxy for – something greater than fruit.

There is evidence to suggest that flowers can provide a sense of greater well-being. The roots of this are not known. Some have suggested that it may be related to the contentedness following consumption fruit, following from above, while others have suggested that it is something greater. Specifically, it has been suggested that flowers provide a tangible link to times and places of fecundity – that is, when and where life was good and productive. While requiring some abstraction, this hypothesis holds appeal in that we do know that both visual and olfactory (scent) stimuli are strong cues for memory recall, especially when coupled together. It may be that, by gifting flowers, we create the impression of better times – of comfort. By instilling a sense of comfort, of fecundity, flowers pave the way for romance to follow.

There is one final possible explanation for how flowers came to be a gift of choice to indicate romantic interest. That explanation is also fascinating, if maybe a little less satisfying. The explanation in question is that our choice of flowers is merely a spandrel.

That’s right, a spandrel.

Here’s what that means… flowers4

The notion of an evolutionary spandrel was introduced by Richard Lewontin and Stephen Jay Gould in a 1979 paper entitled "The Spandrels of San Marco and the Panglossian Paradigm: A Critique of the Adaptationist Programme". The paper made use of a powerful analogy. The analogy was based on the  Basilica di San Marco in Venice. The Basilica was constructed during the Renaissance and features a prominent dome. The dome is supported by spandrels – curved arches of masonry that keep the dome in place. In San Marco, and other Renaissance buildings, the spandrels were ornately decorated. In viewing the spandrels, one gets the impression that they were created to enrich the decoration of the basilica. Instead, in fact, they are merely a decorated by-product of a necessary architectural structure. While elements of Lewontin’s and Gould’s paper have been critiqued, the basic notion of a spandrel is relevant here.

The point is that our use of flowers as a nuptial gift may have emerged because our love for flowers, or indeed anything, stems from another trait. Our choice of flowers has nothing to do with a desire to use flowers per se, but rather because flowers have features that convey a sense of appeal because we’re wired to find something, or some things, with related characteristics appealing. Thus, our use of flowers is very much symbolic of something more deeply ingrained. While this seems somewhat haphazard, it also holds great appeal. It is a reminder that not everything we do is a direct result of some ultimate cause, but rather arises as an indirect by-product of the effects that arise from that cause.

In the end, we are left with a number of possible reasons why flowers might have come to serve as a gift for romantic interest. The challenge now is to determine which of these reasons might have driven the use of floral gifts as a signal of romantic intent.

Irrespective of which, if any, of these possibilities may have driven our use of flowers as a nuptial gift, the message today is still clear. A gift of flowers expresses our desire to be together with someone – to share an intimate moment in their embrace. Be sure to say it with flowers!

Happy Valentine’s Day!

Images: All photographs by Malcolm M. Campbell.

References:

Francisco A & Ascensão L (2013) Structure of the Osmophore and Labellum Micromorphology in the Sexually Deceptive Orchids Ophrys bombyliflora and Ophrys tenthredinifera (Orchidaceae). International Journal of Plant Sciences 174: 619-636

Gould SJ & Lewontin RC (1979) The spandrels of San Marco and the Panglossian paradigm: a critique of the adaptationist programme. Proceedings of the Royal Society of London. Series B. Biological Sciences 205: 581-598

Gwynne DT (2008) Sexual conflict over nuptial gifts in insects. Annual Review of Entomology 53: 83-101

Haviland-Jones J, Rosario HH, Wilson P, & McGuire TR (2005) An environmental approach to positive emotion: Flowers. Evolutionary Psychology 3: 104-132

Madden JR (2003) Male spotted bowerbirds preferentially choose, arrange and proffer objects that are good predictors of mating success Behavioral Ecology and Sociobiology 53: 263-268

Regan BC et al (2001) Fruits, foliage and the evolution of primate colour vision Philosophical Transactions of the Royal Society of London Series B 356: 229-283

Rosas‐Guerrero V, Aguilar R, Martén‐Rodríguez S, Ashworth L, Lopezaraiza‐Mikel M, Bastida JM, & Quesada M (2014) A quantitative review of pollination syndromes: do floral traits predict effective pollinators?Ecology letters 17: 388-400

Stålhandske S (2002) Nuptial gifts of male spiders function as sensory traps Proceedings of the Royal Society of London Series B: Biological Sciences269: 905-908

Tryjanowski P, Antczak M, & Hromada M (2007) More secluded places for extra-pair copulations in the great grey shrike Lanius excubitor Behaviour 144: 23-31

****

flowers5

Leave a Reply


9 × four =