Extinct crop wild relatives

You may have seen coverage of a recent paper in Nature in which Kew researchers quantified the rate of plant extinction over the last 250 or so years. The headline number is about 3 species have been going extinct per year, which is about 500 times the background rate. But I know that what you really want to know is how many of these are crop wild relatives. Well, my friends at CIAT worked their database magic, and came up with the following list of extinct species which are classified by at least one source as a crop wild relative:

Diplotaxis siettiana
Franklinia alatamaha
Helianthus praetermissus
Hutchinsia tasmanica
Ilex gardneriana
Isatis arnoldiana
Lepidium drummondii
Lepidium obtusatum
Mangifera casturi
Musa fitzalanii
Piper collinum
Potentilla multijuga
Rorippa coloradensis
Solanum bauerianum
Solanum cajamarquense
Solanum ruvu
Syzygium balfourii
Syzygium microphyllum
Syzygium palghatense

Which means about 1 per decade or thereabouts. But that, clearly, is just a minimum.

Perhaps I’ll try to map where these plants were last seen.

2 Replies to “Extinct crop wild relatives”

  1. Extinct wild relatives
    As a botanist since I was knee high I simply can’t believe the extinction rate of three species lost a year is 500 times the natural background rate. One example from the list, Isatis arnoldiana (Arnoldi’s woad), is only known from the type collection – an uncertain locality in Armenia. The IUCN Red List has it as `data deficient’: it could still be there or in other localities. Also the natural loss of species could have been immense. Any climatic warming and cooling, Ice Ages for example, will force small populations on peninsulas or mountains to move and `fall off the edge’. We are talking of thousands of species being lost as recently as the climatic cooling – and subsequent rapid warming – of the Younger Dryas. The rate of description of new plant species is about 2000 a year. What is the fuss about?

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