UMIVERSITATIS LATVIENSIS - DSpace

A Survey of the Australasian Species of Ulota.
By N. Malta.
After publishing a survey of the South-American species of
Ulota in 1927, I turned to the Australasian species which form
another large geographic group of species of this genus
in the
Southern Hemisphere. This study, several times interrupted,
has now been completed. For various reasons I have resolved
upon publishing the results of this study before the completion
of the revision of the whole genus. This paper, consequently,
forms a part of the revision of Ulota, intended for publication
later on. In this revision main stress has been laid upon the
variation of morphological characters, the delimitation of species
and their geographical distribution, while the treatment of prob-
lems of nomenclature has been restricted to a few cases. Tak-
ing into consideration some peculiarities of the genus, such as
the presence of widely distributed polymorphous species within
it, attention had to be paid even to minute differences in char-
acters. It seemed that in a work like this there was less harm
in distinguishing very closely related forms, even if some of
them might have to be united afterwards, than in bringing to-
gether and mixing up in one description characters of forms
which are in reality .'different, although they may appear very
alike.
The revision of the Australasian Ulotas has had as an
unexpected result the description of 5 new species.
Four of
them had been confounded with U. lutea — the commonest and
most widespread species of the region. Therefore it is im-
portant first to become clear about the characters of this spe-
cies, ; especially about the leaf form which is the character
always available. Fig. 2 gives an idea of the variation of the
leaf form within the species, and Fig. 1 shows the difference
between the leaf form of U lutea and that of the other species
of the region. If once recognized, with the exception
of a few
cases, it is easy to distinguish the leaf of U. lutea with the
oval or obovate base and the contraction above it from the leaves
of the other species. If U. lutea is rightly understood there are
no difficulties in recognizing the other species, as will be seen
from the key, the descriptions, and especially from the notes
to them.
Acta Horti Bot. Oniv. Latv. VII.
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