The Apogon Section 81 
/. caroliniana [Hdk. Irid. p. 12] not that plant but the typical I. versicolor from which Watson was 
seeking to distinguish it.) 
The cultivation of this Iris presents no difficulty, provided that it is grown in fairly rich soil, 
which is not allowed to become too dry in summer. It does not like lime, but small quantities are 
not so fatal to it as to other American species. 
/. versicolor is one of the numerous Apogon Irises where self-fertilization is effected without the 
intervention of any insect. The tongue-like stigma bends down and backwards, and either collects 
pollen by actual contact with the protruding anther or picks it up from the haft of the fall. As in 
the case of other Irises, in which this phenomenon has been observed, the pollen is very easily jerked 
out of the sacs. 
Seeds germinate very readily, and young plants should flower in their second season. 
I. versicolor has become naturalized in a disused lock on the River Calder in Yorkshire. 
Specimens are in the Halifax Herbarium, and one was kindly sent to me by Mr W. B. Crump. 
XI. The Hexagona Group. 
This group consists of two or three species, according as we regard I. fo/iosa as specifically distinct 
from, or merely as a form of, I. hexagona. The other member is 
/. fulva , and all three agree in possessing the six-ribbed ovary and 
capsule from which the name was probably originally taken. They 
agree also in having a distinct pubescence on the central ridge and 
middle region of the falls, and a curious thick, cork-like covering to the 
seeds proper. 
In the shape of the ovary and capsule (see Fig. 10) and in the 
pubescence on the falls this group seems to be an approach to /. spuria , 
and is possibly the American counterpart of the spuria group which is 
confined to Europe and Asia. Another link between the two groups 
lies in the sticky exudation from the base of the segments and from 
the perianth tube, which occurs also in /. xiphium (see Plates XVII and 
XLIII) and in the members of the spuria group. 
Evidence of the affinity of I. fulva and I. foliosa is found in the 
fact that the former proved to be readily fertile to pollen of the latter. 
Moreover the hybrid, /. fulvala\ has proved not to be entirely sterile, 
as is usually the case with hybrids between two widely separated species 
of Iris. On the other hand, we may take it that the two species are 
distinct, since the hybrid does not show "dominance” in any character, 
but is distinctly a compromise between the features of the two parents 
(see Plates XX and XXI). Thus the foliage neither dies away entirely 
in autumn like that of /. foliosa , nor remains green and of considerable 
length like that of /. fulva. For the young growths push up soon 
after the flowers are over and are 4 or 6 inches long in winter, while those of I. foliosa are still 
only 1 in. long, and those of I. fulva a foot at least. The stem is more like that of /. fulva than 
like that of the pollen parent, but it is sturdier. The flowers are of the shape of I. foliosa, with 
perhaps more rounded segments, and the colour is distinctly a compromise between the terra cotta of 
I. fulva and the blue-purple of /. foliosa (see Plates XX and XXI). The figure of a flower of 
I. fulvala shows the form in which the influence of the colour of /. fulva is most apparent. 1 have 
also from the same pod of seed other plants in which the shade of colour has distinctly more of the 
blue-purple of /. foliosa in it. 
The cultivation of the members of this group is easy, with the exception of I. hexagona, which, 
as is explained in the Observations on that species, needs more warmth than it usually obtains in our 
English gardens to enable it to flower. In their native habitats I. fulva and /. hexagona are semi- 
aquatic, as may be readily seen from the structure of the leaves (see p. 15), but here in such 
conditions the rhizomes do not get that ripening which is essential to their well being. Consequently 
it is better to give these Irises rich soil and plant them in a well-drained and warm position. They 
must, however, not be allowed to get too dry during the growing season in spring and early summer. 
They are best transplanted soon after the flowers have faded, as root growth is then active, and 
the plants become well established before winter. 
The species may be differentiated as follows : — 
I. fulva has long narrow leaves and broad, truncated and deeply emarginate standards, which are nearly as 
broad as the falls. 
I. hexagona and I. foliosa are possibly indistinguishable as herbarium specimens. The typical I. foliosa is 
a very dwarf plant with a short stem hidden among the leaves. On the other hand, there seems to exist 
a whole series of forms growing gradually taller until we reach the large proportions of typical /. hexagona. As 
garden plants, the difference is more apparent, for the leaves of I. hexagona are distinctly greener and less 
glaucous than those of I. foliosa. 
1 The name was derived from fulva and Lamaneet, by which /. foliosa is often known in gardens. 
II 
Fig. 10. Capsule of /. fulva 
(slightly reduced). 
D. 
