181 



produce annual assimilation-shoots several years in succession 

 and by degrees a low cushion is formed from which others 

 arise. Even nodes bearing year-old branching shoots, may 

 again be seen to produce new shoots. 



Calligonum Caput Medusae flowers in June. The flowers 

 are small and reddish, the fruits (figures 11 and 28) are very 

 characteristic (see above p. 88), they are easily transported by 

 the wind and are found massed together in sheltered places 

 in the desert. 



As regards anatomical structure we refer to fig. 29; there 

 are sclerenchyma bands below the epidermis 14 in number, 

 two palisade layers of which the outer one is very loose, an 



Fig. 29. Calligonum Caput Medusae. 



A, Part of transverse section of a young branch: P/iZ., 



Phloem, X 71. B, Detail of A: epidermis, two palisade 



layers, starch sheath and outer cells of the water-storage 



tissue of the cortex. X 250. 



amyloid or starch sheath, and the inner bark formed of 

 bands of sclerenchyma between which is aqueous tissue; 

 this contains much tannin. Other bundles ot mechanical 

 tissue occur between the vascular bundles and between them 

 and the pith. The pith is a large celled, water-storage tissue 

 containing tannic acid. The stomata are sunk. VOLKENS, 

 who (p. 142) described the anatomy of Calligonum comosum 

 found under the epidermis a layer of loose, thin-walled cells, 

 but only one palisade layer. B. JONSSON, who examined 

 an undetermined species from Turkestan, found on the con- 



