THE SUNFLOWER FAMILY 385 
(Lobelia) affords a case of partial coalescence somewhat dif- 
ferent from any of our foregoing examples. The two upper- 
most petals are entirely free from one another, though coal- 
esced with the side ones, and these with the lowest, so that 
all five petals are as if united into a tube which is split down 
the back.! 
In bellflowers (Campanula) the more or less bell-like corolla 
from which they take their name shows no irregularity. 
Mostly herbs with milky juice; flowers solitary or loosely 
clustered, perfect, regular or irregular, mostly gamopetalous; 
stamens five, free or monadelphous and syngenesious; the pollen- 
sacs straight; ovary inferior with two to five axile placenta; fruit 
capsular. 
139. The sunflower family (Composite). Examples: 
Jerusalem artichoke (Figs. 59 I-IV, pages 61, 62), lettuce 
(Figs. 75-77, pages 72-74), and wormwood (Fig. 155, page 
160). 
sae of Helianthus, Lactuca, Artemesia, and Composite 
are given on pages 420, 421. 
More than a tenth of all the species of flowering plants 
belong to this the largest family of seedworts. The very 
characteristic inflorescence is sometimes mistaken for a single 
flower, and was indeed called a ‘‘compound flower” by the 
early botanists. In reality, as will be readily seen, the small 
flowers are borne on a more or less flattened expansion of 
the peduncle, called the receptacle, and form a compact head 
surrounded by an involucre of bracts resembling sepals. As 
if to increase the deception the outer row of florets often have 
what are called strap-shaped corollas formed by a coalescence 
of the petals into one flat piece (Fig. 59 II, III), somewhat as 
in the Indian tobacco but more complete; and these corollas 
radiate so as to look like petals. The inner part of the head 
in such eases as the sunflower is made up of regular florets 
(Fig. 59 III). Many members of the family have only regu- 
lar florets, while still others have all the florets strap-shaped 
or sometimes labiate. 
The calyx may consist of a few papery scales, or of numer- 
1 This condition is indicated in the formulas by P” 5). 
