Eranthis hyemalis Tubergenii Group 'Guinea Gold'
David Victor (Tue, 18 Mar 2008 12:45:27 PDT)

Hi Jim,

You raised a question about the term Tubergenii Group. Its a
cultivar group name i.e. a superset of cultivars which contains the
cultivar 'Guinea Gold'. Someone somewhere has published the name
Tubergenii Group, together with a description of the range of
cultivars that it includes. The rules are laid down in the Cultivated Code.

The aim with such a grouping is to pull together plants that have a
horticultural relationship which are within a Denomination Class (as
laid down by the Cultivated Code, which is normally a genus), but
which otherwise may not be a very close botanical relationship. For
example, it could be a group of variegated plants or a group of early
flowering varieties. However, the groups that are normally chosen
are close and are often a group of interspecific hybrids.

An appropriate example taken from the Code might be in Iris, the
Dutch Group, which includes the complex of early flowering cultivars
arising mainly from I. tingitana, I. xiphium var. lusitanica and I
xiphium var. praecox.

Incidentally, one useful feature of such Groups for horticultural
purposes is that a particular cultivar can be in more than one group,
depending on the need of the author.

Best regards,
David Victor