1 694 A TEXTBOOK OF THEORETICAL BOTANY 



Members of the Bixaceae are all tropical. Bixa orellana is a native of 

 America, but is cultivated throughout the tropics for its seeds, which have 

 a fleshy red seed coat containing a colouring matter known commercially 

 as Annatto or Oilean and used in colouring processes. It is orange in colour 

 and is frequently employed in producing a bright yellow colour in butter 

 and cheese. 



The small family Tamaricaceae, of about lOO species, lives chiefly in 

 the desert and steppes of central Asia and round the shores of the Medi- 

 terranean. One species, Tamarix gaUica (Fig. 1555), is a doubtful native of 

 Britain and other species are often cultivated in gardens. 



Fig. 1555. — Tcniarix gallica. Inflorescences. 



The Passifloraceae are a small family of some twelve genera and 580 

 species. The flowers are very beautiful and so remarkable in appearance 

 that many species are cultivated. The family is widespread in the warmer 

 temperate regions, particularly in America. The plants are mostly climbers, 

 which obtain their support from tendrils in the leaf axils. Pollination 

 is by the aid of insects and humming-birds. The large flowers have five 

 petaloid sepals and five petals. Within the perianth is a corona of long, blue 

 filaments. There is a long gynandrophore bearing five stamens and a 

 terminal ovary with three long-stalked stigmas. The name of 'Tassion 

 Flower" was given because it symbolizes the instruments of Christ's 

 Passion. The gynandrophore is the scourging post, the corona is the crown 

 of thorns, the stamens are the five wounds and the stigmas the three nails 



