Immortal plants

I was both shocked and awed by the ideas offered by the French tropical botanist Francis Halle in his wonderfully titled book In Praise of Plants. In it Halle shows that most animals and plants are fundamentally different, and that we can’t simply generalize from what we know about animal biology to plants. To my delight, Halle also concludes that plants are by far more interesting!

One of Halle’s key concept is that a tree can be viewed as a close-knit colony of many individuals, rather than a single organism, and that this colony has the potential to live forever. What he means is that there is a repeated pattern, and each unit can continue to grow (whether as part of the tree or as a cutting or graft) as long as it contains a bud. The bud, according to this interpretation, can be considered the true individual – it cannot be divided any further. So a tree is like an ants’ nest: individuals die, but the colony persists. 

Apart from providing an interesting philosophical exercise, does any of this matter? It does if you consider colonial organisms to be to all intents and purposes, immortal. Clearly, most trees are mortal: even our most majestic street have a maximum life span of one or two centuries. Structural problems develop. Food and water supplies can’t be guaranteed. Parasitic plants kill their host. Winds blow them down. And so on.

In fact, the longest-lived plants are not the grand trees. Rather, they are certain kinds of seaweed that reproduce, like microbes, almost exclusively by splitting in two (without any sexual fusion), and you could describe their extended families as exceedingly old individuals. All this casts a dark shadow over the efforts of most animals, which at best live for a few hundred years. Being a plant, or a microbe, has its benefits.

Tim Entwisle, Nature Australia.


1. Francis Halle claims that
A. there is no essential difference between animals and plants.
B. animal biology can be used to study plants.
C. animal biology is subject to generalization
D. plants and animals are totally different.

2. According to Halle, a tree
A. is always a single organism.
B. may be seen as a community of sorts.
C. has a very brief natural life.
D. none of the above.

3. Parasitic plants
A. help with the growth of huge trees.
B. interfere with the growth of their hosts.
C. can practically live for ever.
D. resemble microbes.

4. Certain kinds of seaweed
A. reproduce through sexual fusion
B. are parasitic upon microbes
C. are used as fool by animals.
D. reproduce by splitting into two

Няма коментари:

Публикуване на коментар