THE MADDER FAMILY 389 



may take place above the water, and also collect nitrogenous 

 material ; the filamentous leaves of some species are an 

 adaptation to the aquatic habitat ; the shape, colouring, 

 and arrangement of the parts of the flower secure cross- 

 pollination where possible, whilst, if this fails, self-pollination 

 ensues as a result of a delicate readjustment of the position 

 of stigma and anther ; and, finally, isolation by water, secures 

 the plants from attacks by creeping insects, and insures the 

 visits of flying insects, which, alone, are likely to be useful to 

 them. 



Utricularia Protrusa. — A floating, slender plant, with a scape of yellow 

 flowers. Leaves finely divided ; stem bearing minute bladders. Bogs in the 

 North Island. Utricularia novae -Zelandiae has white flowers, and entire 

 radical leaves. This plant was discovered growing upon damp rocks in Pallisor 

 Bay. Utricularia inonanthos is not more than 1 in, in height, with a single, 

 purple flower. The rhizomes bear minute bladders. It has been found in the 

 South Island, and also in Tasmania. 



Rubiaceae. 



The Madder Family. 



Distribution. — A large and widely distributed family of about 4,500 species, 

 divided into two tribes, the Cinchonoidene and Cojffeoidea-e. Most of the species 

 are found in warm and tropical regions. Coffee is obtained from the seeds of 

 Coffea arabica, and Quinine and Peruvian Bark from plants of the genus 

 Cincluma. IijecacuanUa is prepared from the rootstock of Cephaelis Ipecacv- 

 anha, a native of Brazil. Bouvardia is cultivated for its flowers. The New 

 Zealand plants belonging to the family have all inconspicuous flowers, and arc 

 often wind-pollinated, though most foreign species are insect-pollinated. 



Key to the Genera.. 



1. Trees or shrubs. Fruit a berry-like drupe. Coprosma, p. 390. 



Herbs, leaves opposite or wborled. '^ 



•i. Creeping herbs, with opposite leaves and red berries. Nertera, p. 398. 



Slender, erect, or trailing herbs with whorled leaves. 3 



3. Corolla wheel-shaped. tGalium. 



Corolla funnel or bell-shaped. lAsperula. 

 I Not further described. 



