228 
H. F. Wernham. 
Dipsacales. 
In Caprifoliaceae are foreshadowed unmistakeably those features 
which characterize this progeny, namely, irregularity of the individual 
flower and reduction of the ovary-cells to one containing a single 
ovule. In so far as these characters have become fixed in 
Valerianaceae and Dipsacaceae they may be regarded not un¬ 
reasonably as the criteria of a separate cohort, as in earlier editions 
of Engler’s Syllabus, representing a branch-stock, which we may 
name conveniently the Dipsacalian Stock (see diagram, p. 230). 
They seem, nevertheless, to be as fairly entitled to a place in the 
same cohort with Caprifoliaceae as, say, Labiatae with Bignoniaceae, 
or Asclepiadaceae with Loganiaceae. In any case their place among 
the descendants of the rubialian stock seems to be unchallengeable, 
and their herbaceous habit is in keeping with their relative advance. 
In Valerianaceae the tricarpellary ovary with but a single 
fertile loculus already noted among Caprifoliaceae is the invariable 
rule ; and the other tendency of the tribe Linnaeeae (supra) —oligo- 
mery of the androecium—is realized and becomes a fixed character. 
The number of stamens may be one, two, three or four, according 
to the genus, but it always falls short of the number of corolla- 
lobes. The irregularity of the corolla foreshadowed in Capri¬ 
foliaceae is carried through every degree of transition in Valerianaceae, 
from the sub-regular type seen in species of Valeriana with small 
sac or spur or none, to the long-spurred type seen in Centranthus, 
where the floral asymmetry is enhanced by the reduction of the 
androecium to a single stamen. This type of asymmetry must be 
regarded as induced in the individual flowers by insect-visits, and 
not as the result of aggregation. The inflorescence is usually more 
or less lax, of the “ umbellifloral ” type, but the extreme development 
of this type—capitate or sub-capitate—is not uncommon. 
It is in Dipsacaceae that the climax of the aggregation-tendency 
is seen, for in this family the inflorescence is almost invariably an 
involucrate capitulum similar to that of Compositae. Further, 
zygomorphy of the outer florets results in many species in the 
formation of a “ray” series; this zygomorphy is, of course, of that 
type which is the outcome of aggregation. The other type of 
zygomorphy, foreshadowed in Caprifoliaceae and elaborated in 
Valerianaceae, characterizes Dipsacaceae also, so that in the last- 
named family both our types of zygomorphy (chapter I) are present 
in the same plant, the same inflorescence, and conceivably even 
in the same individual flower. 
