Leucojum

johngrimshaw@tiscali.co.uk johngrimshaw@tiscali.co.uk
Sun, 28 Mar 2004 03:11:14 PST
Mary Sue wrote:
> 
> Are you saying that the only two species that will be considering Leucojum 
> are Leucojum aestivum and L. vernum?  Did I read that right? 

Yes, this is correct. L. vernum is the type species of the Linnean genus Leucojum.


>All the rest will now be known as Acis? 

Yes. The type of the genus is Acis autumnalis, and there are about 10 species in all.

>How in the world do you pronounce Acis? 

AYcis or A cis ( a as in apple). A cis is probably more correct in classical terms, but probably most people will use Aycis, as they do when referring to Handel's opera, 'Acis and Galatea'. Acis was a shepherd in Greek mythology.


>Does the world follow what Kew proposes? 

If the world is wise it follows an authoritarive piece of taxonomic work; if not, it can continue to be reactionary. This is fine so long as the user can adduce arguments at least as convincing as those used by the professionals.



This isn't a change based on DNA testing, 
> but a change on the basis of physical characteristics? Is it possible that 
> when DNA is done, that they will all be back together?

The work I am quoting from is an excellent, model study of a group of closely related plants Galanthus and Leucojum, carried out at RBG Kew by
Dolores Lledo, Aaron Davis, Manuel Crespo, Mark Chase and Michael Fay, entitled:
 

'Phylogenetic analysis of Leucojum and Galanthus (Amaryllidaceae) based on plastid matK and nuclear ribosomal spacer (ITS) DNA sequences and morphology.'



It is currently in press, but I was given permission to use it for my lecture at the recent RHS Snowdrop day.

 

They used three different DNA sequences, plus an analysis of 46 physical characters to arrive at a cladogram (in effect a family tree showing evolutionary relationships) that shows that Galanthus is most closely related to Leucojum, and that Acis is a clearly defined group of its own. In consequence their division follows these groups, and makes total sense when one looks at the living plants.


> 
> I think I said it before but if the botanical names keep changing as 
> rapidly as they seem to lately soon we will no longer be able to say to all 
> those people who prefer using common names that using botanical names 
> allows us all to know that we are talking about the same plant. How do we 
> keep up?

This can be difficult, but in horticultural circles the rate of change is generally so slow that it scarcely matters; the new names become instated by slow osmosis, giving plenty of time for everyone to get to know what is being discussed. Most good gardeners only refer to things by their specific name anyway!

> 
> I haven't quite recovered from the thought that the first year my Scilla 
> natalensis is finally going to bloom it has been converted to Merwilla 
> natalensis.

Think about it - how like a Eurasian Scilla is 'Scilla' natalensis? Not very! It is a typical case of a non-European plant being shoe-horned into a European genus by European botanists; now we have more refined taxonomic techniques it is possible to untangle the former mess and place such plants in their correct taxonomic place. A classic example of this are the Australian everlasting flowers, stuffed into Helichrysum by European botanists, now slowly and painfully being disentangled.  


John Grimshaw


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