EVOLUTION OF THE INFLORESCENCE. 531 
other species is expended in the shaping of a single flower for each shoot, is 
here split up, as it were, and utilised for the formation of three or more 
flowers. 
Trollius, Nigella, and Adonis.—These three herbaceous genera may be 
grouped together in regard to the manner in which their flowers are 
borne. In each case the lateral floral shoois, when produced, bear usually 
more than two leaf-structures. The number is somewhat indefinite, and 
their size (foliaceous character) decreases from below upwards, which is 
usually the case in feebly defined inflorescences. Foliage leaves and bracts 
hence merge into one another. 
Another feature these three genera have in common is that the secondary 
floral shoots do not arise from the uppermost leaves of the main axis; the 
three top axils remain barren as a rule. 
In Trollius ewropwus the floral branching is feeble and not carried beyond 
the secondary degree. The commonest case consists of the terminal flower 
and two or three laterals. Trollius would appear to have just departed from 
the condition of the solitary terminal flower. 
Adonis autumnale carries the floral branching a degree or two farther by 
producing, besides more secondary branches, tertiary floral shoots to some 
extent. 
Nigella 
greater, shoots to the fourth degree being produced. 
It is interesting to note that in Adonis autumnalis and all species of 
Nigella, being annuals, the plumular axis must, barring accidents, end in 
a flower. This is invariably the first one to open. 
Ranunculus.—In this, the representative genus of the family, a more 
definite type of the lax dichasial inflorescence has been evolved than in the 
foregoing. Ranunculus acris and R. aconitifolius afford good examples of 
repeated dichasial branching, floral shoots to tho fifth degree being often 
produced. Of secondary shoots, however, more than two—three to six, 
in fact, are formed. Afterwards the branching is strictly dichasial, each 
shoot being composed of the terminal flower and a pair of bracteoles. 
Unlike Trollius, Adonis, and Nigella, the uppermost leaves (bracts) of 
Ranunculus produce from their axils secondary flower shoots. 
felleborus.—Solitary terminal flowers recognised as primitive can hardly 
be said to exist in this genus, but some species come very near to possessing 
them. Three main types of flower-arrangement can be recognised in the 
a genus wholly composed of annuals ; the floral branching is still 
genus :— 
A. Inflorescence feebly differentiated, very lax and of few flowers. The 
majority of the species, e. g., H. viridis (fig. 3, A), H. orientalis. 
B. Flowers solitary or in pairs: H. niger (fig. 3, B). 
C. Inflorescence more defined, panicled, and of many flowers: 
H. foetidus (fig. 3, C), H. lividus. 
