CONTORTS. 



543 



Erythrcea (Centaury, Fig. 581) ; corolla most frequently salver- 

 shaped. The anthers ultimately become spirally twisted (E). The 

 style prolonged, deciduous. The flower has the Lo&eZm-arrangement, 

 i.e. the median sepal is anterior; the corolla is rose-coloured (in the 

 native species). The capsule is semi-bilocular (Fig. 581 F, G). 

 Cicendia has a low creeping stem, fine as a thread, and small, yellow flowers, 

 4-merous (without twisted anther). Chlora (Yellow-wort) 6-8-merous. 



FIG. 581. Erythrasa centaurium. Inflorescence, flower and fruit : br 1 , br 2 floral-leaves of 

 the 1st and 2nd order ; Gf a valve of the capsule separated from its fellow. 



2. MENYANTHE^. Menyanthes (Buck-bean) deviates in several 

 respects from the type of the order. The leaves are scattered and 

 in M. trifoliata, trifoliate ; the corolla has valvate aestivation ; the 

 testa is also very hard (thin in the true Gentians). They are 

 aquatic plants with creeping rhizome ; the flowers borne in racemes, 

 with terminal flower, heterostylous. The corolla is funnel-shaped 

 with a very hairy throat. Limnanthemum with floating leaves, like the 

 Water-lilies. 



575 species; distributed over the entire globe, but most numerous in Alpine 

 districts. Neithei poisonous nor nutritive plants are found, but several are 

 used in medicine on account of the bitter properties so prevalent amongst them. 

 OFFICINAL: the roots of Gentiana lutea. The roots of other species, e.g. G. 

 purpurea, punctata and pannonica (Europe) end the leaves of Menyanthes tri- 

 foliata are medicinal. Some are grown as ornamental plants on account of 

 the pure (often deep blue) colour of the flowers. 



Order 2. Apocynaceae (Periwinkles). Trees and shrubs 

 (also lianes), less frequently herbs, generally with latex. The 

 leaves are opposite, simple, entire, without stipules ; the flowers are 



W. B. 



NN 



