25 
Notes on the Corolla in the Composite. 
with tubular and truly ligulate ( i.e ., Cichoriaceous) corollas are 
modified bilabiate forms, we find many variations as confirmatory 
evidence. The ordinary ray floret is usually three-toothed with the 
posterior lip represented by the perfectly smooth surface at the top 
of the short tube by which the corolla is attached to the receptacle. 
Frequently, however, the short tube becomes more or less elongated 
and one or both of the suppressed lobes become developed to give 
a four- or five-lobed corolla with a deep indentation on the posterior 
side. 
A typical case in Heleninm autumnale was observed in the 
Cambridge University Botanic Gardens. The ray florets in some 
capitula were all markedly tubular, some being equally five-lobed 
and truly tubular (Fig. 4), while others were tubular with a deep 
indentation between the posterior lobes (Fig. 5). Still others 
showed four lobes with no trace of the fifth (Fig. 6), and others 
again, showed the fifth lobe more or less aborted (Figs. 7, 8). In a 
few florets the posterior lobes were large while the other three were 
united into a larger lobe with three teeth (Fig. 9). Thus in one 
capitulum could be seen most of the variations of the bilabiate ray 
floret. Similar abnormalities have been observed in Calendula spp. 
(Figs. 10, 11) and in other genera. 
The four-lobed corolla is comparatively common among large 
ray florets and the vascular system is correspondingly enlarged but 
the vascular supply of the floret is the subject of a separate study 
and need not be considered here. It seems, however, to be more 
or less closely dependent on the width and size of the corolla. 
The five-lobed, pseudo-ligulate floret is rare and even when it 
occurs, the lobes are not usually uniformly developed nor do they 
resemble, except superficially, the truly ligulate floret of the 
Cichoriaceae. All these variations are obviously partial reversions 
to the tubular, five-lobed type. 
Another tendency shown by the three-lobed corolla is the 
development to a marked degree, especially in the Mutisieae (Figs. 
12-15) of the posterior lip. In Calendula and other genera showing 
the ordinary ray floret, the posterior lip may be represented by a 
small lobe lying at the base of the posterior indentation. This lobe 
may be larger and subulate (Fig. 10), or it may be divided (Fig. 11), 
orming a two-lobed lip of varying size. Distinctly bilabiate forms 
have been observed occasionally in most tribes (vide 3, 7 and 32 
above). 
