


NATURAL ORDERS 123 
fic ENO chiet differences in this group are the 
Heliotrope undivided ovary, and the terminal, not gynobasic, _ 
Group. - style. 
Pollination 1 ne colour of the Boraginacee is interesting. 
and Colour Many species undergo changes in colour: thus 
eee Order. orget-me-nots are white, pink, or blue; Viper’s 
Bugloss is red when first opening, then it turns blue. 
Comfrey also has 3 varieties. Muller thinks that white 
and yellow were, in some genera at any rate, the primitive 
colours, and that violet and blue have been preceded by 
red in many cases. This theory is borne out by the fact 
that many blue and violet species have white and rose-red 
varieties. The development of violet and blue colours is 
probably an adaptation of the flower in relation to the visit 
of insects. Many different species of insects visit the 
Boraginacex: flies cross- pollinate those with short-tubed 
corollas ; those which have long corollas protect their honey 
from all except bees, which cross-pollinate Lungwort, Borage, 
and Alkanet. All these have blue flowers. The blue colour 
probably gradually developed in order to attract bees, which 
alone had long enough probosces to reach the honey of the 
long-tubed corolla. 
There are about 1,150 species, growing mostly 
Distribution. . 
in the north temperate zone in dry situations. 
SOLANACEZ. 
BITTERSWEET (Solanum Daulcamara). 
A shrub with alternate leaves, sometimes with 
two lobes at the base, otherwise simple, with margin entire. 
Inflorescence : cymose. 
Flower : regular and hypogynous. 
Calyz : sepals 5, joined, inferior. 
Corolla: petals 5, joined at the base, and forming a short 
_ tube; bluish-purple, spreading out, and slightly reflexed. 
 Andrecium: stamens 5; the anthers are bright yellow, 
Type. 
