Saturday, November 7, 2009

Wim Crusio: "The only reason why I chose to distinguish 5 varieties in A. barteri was purely pragmatic" (an "Amazonas"-Interview) – Part II

“Amazonas”: Recently we have discussed a morphological feature, that is not presented in your revision. In this сonnection we would like to ask one more question: One of the distinguishing morphological features of Lagenandra genus is the involute vernation, in which both margins on opposing sides of the leaf are rolled up. All Anubia have the convolute vernation, it means the leaf is rolled from one margin. But leaves of different species are rolled up in different ways (clockwise or counterclockwise). What determines the direction of leaves' rolling up? Is this feature stable within this species?

Wim Crusio: Well, I have to admit that I never looked at this! I don't know whether this feature is stable within species. In general, very few plant species (and even rather few animal species) are lateralized, so I would not be surprised if this feature would be determined more or less randomly for each individual clone. In culture, species may appear to be less variable than they are in reality, because we may see many different plants, but they probably belong to only a few clones.

“Amazonas”: What do you think is the place of the plant under the trade name "Anubias coffeefolia" in the taxonomy of Anubias? Is it a new species or an artificially grown hybrid?

Wim Crusio: I have never seen the plant alive, only on photos. I think it is one of the many variants of A. barteri. I have seen many collections of this species from the wild and it is extremely polymorphic.

“Amazonas”: Among all species of Anubia only Anubias barteri var. nana is successfully grown being fully submersed. This feature is passed on to all interspecific hybrids of this Anubias. In this сonnection there are some suppositions about the existence of a certain gene responsible for this feature (an ability to grow being submerged into the water for a long time). What do you think about it?

Wim Crusio: As a geneticist, I strongly doubt that one single gene could be responsible for such a complex character as being able to live submerged. As far as I know, A. heterophylla has been kept submerged with success, too, as is the case with most (or even all) varieties of A. barteri.

“Amazonas”: To what species would you refer this Anubias (On the picture you can see a mature Anubias more than 2 years of age)? What do you think is the reason for Anubia leafstocks sometimes having unusual (reddish-brown or red) colouring?

Wim Crusio: This looks like either A. barteri var. angustifolia or a very narrow-leafed form of A. afzelii. You will have to compare the size of the inflorescence with the dimensions given in my revision. It is almost certainly the first one, though.

“Amazonas”: Anubia-fanciers noticed that the spatha of Anubias barteri subspecies can have a slightly lowered or volute end. your revision says that you cultivated many of Anubias genus. Have you faced such differences? What might it depend on? On conditions of plants growing? Or on the physiology of a particular plant?

A: Аnubias barteri var. caladiifolia with a slightly lowered end of the spatha, the first day of blooming. B: Anubias barteri var. nana: this is not the first day of blooming, but one can see that the spatha is not full volute.

Wim Crusio: To find out what causes these differences, one would need to breed these plants under different conditions and perhaps also produce crosses between them.

“Amazonas”: Some of us (Anubia-fanciers from Russia, Ukraine and Moldova) keep Anubias sp. Gabon. Do you know this plant?

The pictures of it are here

Wim Crusio: This is a form of A. barteri. Probably var. barteri.

“Amazonas”: Taxonomy is a relative science. As far as I know, modern taxonomists try to avoid such notions as "variety" and "subspecies", using only the notion "species". What do you think about it, taking into consideration the Anubias barteri case?

Wim Crusio:I agree with that completely. As I wrote in my revision, the borders that I drew between the different varieties are rather arbitrary. Somebody else would perhaps have drawn them differently or distinguished more (or fewer) varieties. It's a bit like distinguishing between tall and short people, they are extremes of the normal distribution, but within a given population, you can find the whole range from short to tall.

“Amazonas”: All the pistils of Anubias gracilis we have seen bevor were reddish-pink. Can the color be the key to the specification of the genus?

Wim Crusio: Perhaps. But A. gracilis appears to be very rare and it is very well possible that all plants in cultivation stem from the same clone. I have seen reddish-pink pistils also in A. hastifolia, I think. At this point, I actually have big problems drawing the border between barteri and gracilis...

“Amazonas”: What question was the most interesting or maybe difficult for you?

Wim Crusio: The most difficult question was the one about whether I still keep aquaria, because it made me feel nostalgic and I really would like to have some free time again to devote to this wonderful hobby!

Interview: Alexander Grigorov.

Photo: Sergey Gerasimov, Dmitry Loginov and Konstantin Ilyin.

© Alexander Grigorov

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