Origin and Development of the Composite. 83 
may he reduced to a certain extent. Siphocampylus rcticulatus, 
for instance, shows in some specimens an inflorescence which 
might almost be described as an involucrate umbel. 5. corymbiferus 
also shows a very close approach to a capitulum, but the inner 
bracts and the calyx are only moderately reduced (see also 
Lysipomia acaulis, X, 72, p. 198). In the Campanuloideae the 
involucre is diffuse in Pliytcuma , uniseriate in P. comosum, biseriate 
in Hcdraeanthus tenuifolius and multiseriate in fasione. 
Habit. A very good account of this subject is given by 
Bentham (6). The more widespread types are herbaceous, 
perennials or annuals, as in the Composite, and, as in that family 
and many others, the insular species are more or less woody. As 
in the Compositae also, the scrambling climbers are most abundant 
in open scrub and around the edges of the tropical forests, especially 
in South America. Erect woody forms occur at high altitudes* 
especially in the Andes, where the ericoid, abietoid and lycopodioid 
forms are very interesting. Similar forms occur in the Compositae, 
(see Chap. X and Weberbauer, X, 72, Fig. 26, C and F, Goebel, 
X, 32, PI., VIII, Figs. 2a-2b and Schimper, IX, 32, Fig. 409). 
The perennial herbs develop large, coarse plants with a racemose 
inflorescence in some regions and the erect Lobeliae of Africa may 
be compared with the Ligulariae of Asia. It remains to note that 
the leaves are usually alternate. 
Latex. The occurrence of laticiferous vessels in the Lobelioidese 
is also of interest. Our knowledge of these structures in the 
Lobelioidese is by no means complete, and the absence of latex in the 
species of Rhizocephalum and a few other genera which have been 
examined is significant. Latex is present in some species of 
Siphocampylus, Centropogon and many other genera; Lysipomia does 
not seem to have been examined (see Chap. XII, C). 
Summarising the points in which the Lobelioideae show 
characters and tendencies, or lines of orthogenesis, leading towards 
the Compositae we have— 
1. Inferior or semi-inferior ovary with anatropous ovules. 
2. Reduction of the quinquelocular ovary of the lower 
Campanuloideae to a bilocular ovary and finally to a few ovules on 
more or less basal placenta. 
3. Bifid style with collecting hairs; scattered or in a ring, and 
recurving of style branches to give ultimately self-pollination. 
4. Pollen-presentation mechanism, protandrous and the same 
in principle, with the nectary at the base of the style and a sugges¬ 
tion of irritability of the stamens. 
