ICBN nomenclature of Hieracium

Tue May 7 11:04:06 CDT 2002

Dear Taxacomers,

I have an unusually critical nomenclatural problem that I hope someone with more experience, or at least other opinions, could suggest a solution for. The case is the following:

Elias Fries (1819) described the apomictic taxon Hieracium vulgatum var. caesium Fr. based on Swedish material from Braås in Smoland. In 1845 he himself raised it to the rank of species. The original description is very vauge and is not in itself sufficient to fix its application. After Fries, the first botanist to work on Hieracium in Sweden was S. Almquist. Almquist first (1871) applied the name H. caesium Fr. to a glandular taxon but since this was clearly contrary to the original protologue, Almquist later(1881) changed opinion and applied the name H. caesium to another species, hereafter referred to as 'taxon X'. (The taxon first identified as H. caesium by Almquist was at the same time renamed H. laeticolor. Almqu.). From ca. 1890 onwards several excelent botanists worked with Hieracium in Sweden and they all used the name H. caesium for 'taxon X' and it is still used in that sence here. Outside Sweden (and Danmark -Norway), the name H. caesium has been used, and is still in use, in another, usually wider sence. It has sometimes been applied to particular apomictic micro-species that not present in Sweden, but more commonly it has been used in a wide sence including both 'taxon X' and other more or less similar micro-species.

For long, no extant type material of H. caesium were known. However, most recently, my colleague Alexander Sennikov managed to find a specimen kept in a separate collection in UPS. This specimen has belonged to Fries friend Thunberg and is annotated 'H. caesium' by Thunberg and has the inscription 'Juxta Braås in Smolandia. Fries' with an unknown handwriting. Thus, this specimen has certainly been collected by Fries at the type locality and from external evidence it appears likely that it was done before 1819, but there is no 'internal evidence' to prove this. The specimen is in accordance with the original description of H. vulgatum var. caesium in many respects but differs in the shape of the leaves proving that Fries must have used other, and at least in this respect different, material for his original description. Both I and A. Sennikov have had a very close look at this specimen. It is a very weak specimen and is not really typical for any species known from Sweden. A. Sennikov first proposed that it belonged to H. laeticolor Almqu. but since that species is not known from any other locality in that area I became very suspicious and having revisited the specimen Sennikov changed his mind and decided that it belonged to an aberrant form which he refers to H. basifolium (Almqu.). He states that the same form is known from a very few other collections from Scandinavia but I have not seen and such material although I have checked almost all material in Swedish herbaria from Smoland. In my opinion this particular specimen may well belong to H. basifolium but I considerit to bad for any definite determination. However, I and Sennikov perfectly agree that it does not belong to 'taxon X'.

What to do in this case? Sennikov has proposed to change the application of the name H. caesium Fr. to what is today known as H. basifolium, to lectotypify 'H. caesium' with the specimen in Thunbergs collectiuon described above, and to apply another name (H. plumbeum Fr.) for taxon X. This will certainly lead to much confusion in Sweden where 'H. caesium' has always meant 'taxon X', but it may have less fatal consequences in other countries. However, since the proposed lectotype is so weak and untypical there will still be uncertainty about the application of 'H. caesium Fr.' My first intention was to propose conservation of 'H. caesium' with a new type as 'in current usage', i.e. applied to 'taxon X'. Sennikov, taking advice from some experts on nomenclature, has argued that it is impossible to conserve this name, partly because it has allready been used in different sences (although mainly outside Sweden) and partly because  'other people normally do not want to mess with the unstable nomenclature of apomicts'.

Should I accept this argumentation and proposed lectotypification and from now on apply the name H. caesium to 'H. basifolium' and H. plumbeum for taxon X? If so, would it be suitable to select an epitype for the lectotype which represents the typical 'H. basifolium' (i.e. is rather much different from the proposed lectotype for H. caesium). Or should I continue to argue in favour of conservation of the name H. caesium as applied to 'taxon X'? Any suggestions? A way to avoid the whole problem would be to lectotypify H. caesium with the proposed material but consider it as belonging solely to a very rare species not known from any extant locality, and thereby in practice exclude the name from any contemporary usage, but I suppose this 'solution' can not be recomended, or?

Torbjörn Tyler

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Torbjörn Tyler   /  Projekt Skånes Flora

Department of Ecology
Systematic Botany
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