688 



BOTANY 



PAKT II 



Family 2. Loganiaceae. Species of Strychnos, which are trees or lianes climbing 



by means of hook -tendrils, 

 yield the well-known curare 

 of South America, and the 

 arrow poison used by the 

 Malays. 



OFFICIAL. Strychnos nux 

 vomica is a small tree or shrub 

 of Southern Asia, the fruits 

 of which are berries with a 

 firm rind ; in the succulent 

 pulp a small number of erect, 

 circular, disc - shaped seeds 

 are embedded (Fig. 740). It 

 yields NUX VOMICA and 



STRYCHNINA. GELSEMII 



RADIX is obtained from Gel- 

 semium nitidum, which is a 

 native of North America. 



Family 3. Gentianaceae. 

 This is recognisable by the 

 unilocular ovary and the 

 clearly contorted corolla when 

 in bud (Fig. 741). Gentiana, 

 is a genus with numerous 

 species. Plants of larger or 

 smaller size, especially abun- 

 dant in the Alps. Flowers 

 brightly coloured. This genus 

 affords one of the best ex- 

 amples of seasonal dimor- 

 phism, i.e. the splitting of a 

 species into two closely related 

 forms which develop at 

 FiG.736.-OZeamro^ainfruitanat. size). OFFICIAL. different seasons. Since the 



FIG. 737. Olea europaea. A, Corolla spread out. 

 B, Calyx and ovary in longitudinal section. (En- 

 larged. After ENGLER-PRANTL.) 



FIG. 738. Olea europaea. Drupe, h, Stone. 



height of the vegetative period of the alpine meadows coincides with their 

 annual mowing, this expresses itself in the distinction of an early form, fruiting 

 before the meadows are cut, and a late form developing after this has taken 



