204 



AIZOACEAE 



the Nerine the cells of the epidermis are pear-shaped, not in section only luit 

 as a whole, they are here long and narrow like a wedge, and t heir apex is 

 consequently not dome-shaped but formed like a rounded ridge [Plate 51, A, 2). 



As a result the light issuing from each cell does not form a luminous spot hut 



a brilliant line, and this is the cause of the satin-like gloss of the petals of 



almost all species of Mcscmbrianthemum. 



Mesembrianthemum edule occurs with yellow or purplish flowers, while 



those of the closely allied .1/. acinaciforme are always a deep purplish pink. 



Both differ also in the shape of their leaves (see figures of sections), and in 



the latter species there are always two floral bracts below the flower. 



The stamens of this and some other species of Mesembrianthemum arc 



irritable like those of Opuntia, bending inwards when touched by insects, e.£. 



bees, which visit these flowers. 



Both species are very useful for the fixing of sandy soil along roads or 



embankments and even among dunes, 

 provided that the wind cannot bury 

 them with new sand. Their fruits are 

 edible and known under the name 



hottentot figs or Zuurvygen. The 



numerous small seeds are embedded in 

 a sweet pulp, which is slightly acidulous 

 on account of malic acid. The fruit 

 is, morphologically, a pulpy pome like 

 a guava or pomegranate, and occurs 

 only in this section of the genus, while 

 all the other species possess capsular 

 fruits. These capsules are highly hygro- 

 scopic, remaining closed when dry, 

 contrary to the more general behaviour 

 of capsular fruits, and opening their 

 1. Capsule in dry weather. 2. Same- valves in rainy weather, just at a time 

 in wet weather. whcn thc seeds fi n( j favourable con- 



ditions for germination [Fig. 93, B). 

 1 he root of M. clitic is used medicinally under the name gaukum. 

 Mesembrianthemum criniflorum. An annual species of the South West, 

 developing its foliage during winter, flowering in spring and disappearing 

 when thc dry summer comes. The colour of the flowers varies considerably, 

 being generally more purplish than in the variety represented, but always 

 very brilliant. 



Mesembrianthemum aureum. This small shrublet is a native of the 

 western districts and one of the few species which are cultivated in Cape- 

 gardens. A rockery covered with this or the allied M. auranl'uuum forms 

 a most gorgeous sight in spring. 



Fig. 03, A. Mesembrianthemum 

 bilobum Marl. Corpusculum in long, 

 section, the stalked ovary entire in the 

 central cavity. B. M. nobtle Haw. 



