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17.

much different from that of some of the North American species, the basic
chromosome number is the same, and the morphology and size of the chromosomes
is similar or identical.

Another group of the collective genus Swertia has the basic chromosome
number x = 5 and pollen morphology and gross morphology that indicates a
much closer relationship with Lomatogonium A. Br. Indeed, Smith (in Nilsson
1964, 1967a) concluded that this group of Asiatic Swertiae actually belongs
to the latter genus and so he transferred a selected number of these species
to Lomatogonium. According to Nilsson (1967a), the East African species
named as the S. crassiuscula-group by Hedberg (1957) are more or less
identical in their pollen morphology to certain species of Lomatogonium;
since they are also characterized by the same basic chromosome number, x = 5,
and a similar chromosome morphology, in addition to several gross morphological
traits, a transfer of this group to Lomatogonium seems to be well conceived.

As far as cytological information goes, the group accepted as the genus
Ophelia D. Don in a restricted sense by Grossheim (1952) is characterized
by the basic number x = 6, although only tetraploid species have been studied
so far. It seems to be wise to retain this group as a distinct genus and to
transfer only its section Dimaculatee to Frasera rather than the entire genus
as proposed by Toyokuni (1965a), since this would secure homogeneity of
both genera. The monotypic Siberian genus Anagallidium Griseb., which was
retained by Grossheim (1952), is cytologically and palynologically
unknown, so its systematic position remains insecure.

These alterations would reduce Swertia s.str. to a genus of perhaps less
than fifty species of alpine situations from East Africa and Central Europe
through southern and eastern Asia to western North America. The genus Frasera
would include more than thirty species distributed from East Africa and South
Asia to eastern North America. The genus Ophelia includes about twenty species
of Asiatic mountains, and one Central Asiatic species belongs to Anagallidium.