192 THE STORY OF PLANT LIFE 



to warm and dry regions, being adapted to drought, 

 the members of this group have a wide range. 



They are herbaceous plants of low stature, spreading 

 or prostrate. The rootstock may be woody and 

 perennial with annual flowering stems. The leaves 

 are opposite or alternate, entire, toothed. There are 

 no stipules in Knawel. The other types possess 

 membranous stipules. 



The flowers are small, hermaphrodite, in cymes, 

 terminal or axillary, rarely solitary. The calyx is 

 live-lobed (four or three), and the sepals are distinct 

 or united below, persistent, closing over the fruit. 

 The petals are small or wanting, of the same number, 

 inserted at the base of the calyx. The stamens are 

 hypogynous or perigynous, with short anther-stalks, 

 which are distinct or united at the base, as many as 

 the sepals or fewer, placed between the petals. The 

 anthers are small. If a disc is present it is annular. 

 The ovary is free, ovoid, one-celled. The style, if 

 present, is two- to three-fid. The stigmas are decur- 

 rent. The ovule is single, erect, or pendulous. The 

 fruit is a utricle enclosed in the perianth, and one- 

 seeded. The seeds are round, kidney-shaped, with a 

 straight, curved, or annular embryo. 



The group includes no plants of economic import- 

 ance. 



Knawel (Sclevanthus annuus). 



Knawel is derived from the German Knawel and is 

 a mere book-name. The name Spleranthus is from 



