Appearances can be deceptive: Eryngium campestre (field eryngo)

 

So this is another thistle in the garrigue, right? Wrong. It’s not a member of the thistle family at all – they’re with daisies, cornflowers and chicory in the family Asteraceae (used to be called Compositae), and Eryngium is, like fennel,  in the family Apiaceae (used to be Umbelliferae).  One clue is in the repeated branching of the stem into umbels (stalks or rays branching off from one point), and  another is in the stamens, which are not fused together as in thistles, if you look closely.

 

One name for this in French is the ‘herbe aux cent têtes’, due to the umbels, another is  chardon roulant, rolling thistle, and the similar l’èrba rotla means the same in Occitan.  Why? Because although the plant is a perennial, the stem can break off when it dries and blow in the wind to scatter seeds elsewhere.  But normally, the hooked seeds are dispersed by furry animals – it relies on mammals to spread.  Another characteristic is its long root system of up to 5 metres, which, like its leathery and spiny leaves ,is an adaptation to dry conditions. The root is also often  parasitised by a fungus, Pleurotus eryngii, which produces edible mushrooms, or by the parasitic flower Orobanche.   So it’s not just a solitary thistle in the wilderness, but a whole ecosystem.

 

Pleurotus eryngii

It’s that kind of shift in view which characterises the work of one of my favourite writers on natural history, Stephen Jay Gould (1941-2002). A New Yorker who became Professor of Geology and Zoology at Harvard, he is best known for his long series of monthly essays which appeared under the heading ‘This view of life’ in Natural  History magazine, and which he collected in many books. He wrote little on botany but his overall approach to the history of life on earth offers much to those seeking to understand plants, and to those who appreciate good  prose style.  At their best his essays are at the same time intricate and clear, profound and entertaining, personal and research-based.  In his collection Bully for Brontosaurus he distinguishes two sorts of nature writing: the Franciscan (after the saint) which produces a kind of nature poetry, and the Galilean which takes a ‘delight in nature’s intellectual problems’. He put himself firmly in the latter group.

 

Stephen Jay Gould

His relevance to botany? His consistent desire to understand how evolution works, rather than being satisfied with the formula ‘If it exists, it must be adaptive’. With the biologist  Richard Lewontin, he coined the term ‘spandrel’ in evolutionary theory, after the triangular gaps between arches he noticed in St Mark’s Cathedral in Venice: a feature which might have no function or evolutionary advantage, but might arise as a consequence of other structures (arches and a dome, in the case of St Mark’s).  Male nipples might be one example, existing only as a developmental relic of the necessary female equivalent, as he explained in his essay ‘Male nipples and clitoral ripples’. A botanical parallel might be some colours in flowers which are not visible to the insects the flowers attract (insects detect more ultraviolet than we do).

He appreciated just how plain weird many living things are, often resulting more from contingency or ‘happenstance’ than adaptation or design. Why else does the fern Ophioglossum reticulatum need 630 pairs of chromosomes (that’s right, 1,260 per cell)? As he explained in the essay ‘The ant and the plant’, some polyploidy or doubling of chromosomes can encourage variation, but in this fern the mechanism has gone beserk.

 

Ophioglossum reticulatum – Adder’s tongue fern

He realised that evolution was not a gradual process of accumulating small variations as Darwin had proposed, but sometimes ran very fast,  producing radical changes, while at other times there were long periods of stasis: the theory known as ‘punctuated equilibrium’ (proposed by Gould and Niles Eldredge in 1972). This remains a major explanatory hypothesis for animal evolution, though it may play a smaller, if still significant, part in the evolution of plants.  To illustrate his style, when objectors called his theory ‘evolution by jerks’, he replied that gradualism was ‘evolution by creeps’.

I also admire Gould for the breadth of his interests and for his awareness of the social context of science. He understood how religious beliefs had hindered the interpretation of fossils, for example, and this is a major theme of his fascinating book Wonderful Life. He was a committed campaigner against creationism and its attempted inroads into American education. He knew that science cannot be ‘value-free’ and his book The Mismeasure of Man is a passionate but also scientific explanation of why the concept of IQ testing is flawed and inherently racist. Does this apply to plants? Of course. Just as the word ‘intelligent’ can be a useful adjective, but can also parade as an objective phenomenon to be studied and measured scientifically, so too a plant can seem a biological organism to be described and understood as an individual, though it never exists on its own. To the farmer, Eryngium campestre is an invasive weed, to the mushroom hunter it’s just the food source for what he wants to collect, to an animal it’s an annoying burr, to the botanist a good example of a xerophyte adapted to dry conditions.  And plant, fungus, animal, climate and soil (maybe even botanist) are all developing together in an evolving ecosystem. In another example of putting genetics in context, Gould’s colleague Lewontin campaigned against genetically modified crops, seeing them as an advantage to agribusiness rather than to the farmer or consumer.

Gould and Lewontin were both members of what was known as the ‘radical science movement’, together with the American psychologist Leon Kamin and the British biologist Steven Rose.  There’ll be more of their radicalism to come in future posts, including reference to their 1984 manifesto Not in our genes, and Rose’s stimulating book Lifelines.

On to some music, and the radical poet and musician Gil Scott-Heron with one of his earliest and most influential songs, The revolution will not be televised, from his first album, Small talk at 125th and Lenox. Yes, radicals, revolution and rolling thistle – you were there before me.  But there’s another parallel. The song gets its power from the two ways of looking: our familiar and comfortable trappings of life suddenly seem ridiculous when the streets erupt.