[Taxacom] Diaeresis current usage in plant genus names?

[Tony.Rees at csiro.au]

A recent post from Paul Kirk mentioning in passing the fungal genus "Nais" (in fact: Naïs) has prompted me to consider how I should best store such names (and their respective species) in relevant database/s under my control. According to the botanical Code, the diaeresis (ë, ï, ö etc.) is allowed in Botanical usage (other diacritics not permitted), while in Zoology I believe no diacritics are allowed.

A scan of botanical genus names in my database that include the diaeresis gives a total of approx. 105 genera, including (according to Index Nominum Genericorum) the Linnaean genera Aloë, Hippophaë, Isoëtes and Lagoëcia among others. I am used to seeing (e.g.) Isoëtes written with the diaeresis reasonably often, but what about (for example) Aloë, with its 400-odd valid species. I guess it is possible to build a system that maintains parallel sets of names, one with and one without the diacritic in each case, however it seems a little undesirable.

NB at present, for example an ITIS search for Aloë or Isoëtes fails (!) but works on the plain variants, Catalogue of Life (web interface) succeeds on both the plain and diacritic versions of Aloë or Isoëtes but returns the relevant names without the diaeresis (I believe that is how the data are stored for those names) while for others e.g. Oxychloë it both stores and returns the version with the diaeresis (and either version is accepted for searching), and Index Fungorum (e.g. for the genus Naïs) succeeds on both the plain and diacritic versions and returns the relevant names with the diaeresis.

So my main question is for how many of these genera is it usual to keep the diaeresis in the stored names, and are there cases where "current usage" is to omit it?

The actual names include the following:

(Algae): Adenoïdes, Agloë, Chlorotetraëdron, Cryptozoön and 18 more
(Fungi): Aseroë, Chiloëlla, Clathroïdastron, Danaëa, Dothichloë and 13 more
(Higher plants): Adamboë, Aglaë, Aloë, Alseïs, Antheëischima and 58 more.

I can supply a more complete list if interested...

Any comments will be welcome.

Regards,

Tony Rees
Manager, Divisional Data Centre,
CSIRO Marine and Atmospheric Research,
GPO Box 1538,
Hobart, Tasmania 7001, Australia
Ph: 0362 325318 (Int: +61 362 325318)
Fax: 0362 325000 (Int: +61 362 325000)
e-mail: Tony.Rees at csiro.au
Manager, OBIS Australia regional node, http://www.obis.org.au/ 
Biodiversity informatics research activities: http://www.cmar.csiro.au/datacentre/biodiversity.htm
Personal info: http://www.fishbase.org/collaborators/collaboratorsummary.cfm?id=1566