- 94 



the lower ones die early, but the axillary shoots remain 

 active (Translocation of water). 



Closely related to the last is Agriophyllum latifolium 

 (fig. 74). The chief difference is that this plant has broad, 

 opposite ovate or almost circular leaves with long stalks, 

 and the primary vein terminates in a thorn. The upper leaves 

 all show transitions towards the narrow, grass-like leaf of 

 the preceding species. All the leaves support long-lived bunches 

 of thorns as in the former species. 



Salsola Kali also belongs to this type together with the 

 allied species, S. sogdiana (fig. 76) and aperta, also Cornulaca 

 Korschinskyi (fig. 68) and Arthrophytum subulifolium, all thorny- 

 leaved, stiff, branched plants, and annuals except the last 

 which is an undershrub. Acanthophyllum claims, an under- 

 shrub with prostrate branches and stiff, thorny leaves, should 

 also be included here. Ceratocarpus arenarius (fig. 66), frequently 

 a clay-plant, may also be found on sand; it is exceedingly 

 branched and thorny and is generally globular in shape. The 

 parenchyma dies away, but the midrib remains as a long, 

 pointed thorn (comp. above p. 72 and chapt. 13). 



Convolvulus erinaceus, an undershrub very abundant loc- 

 ally in the Sand-desert, also assumes the globular form. In 

 spring it has true narrow foliage leaves at the base, but later 

 on only scales are present and the work of assimilation is 

 entirely carried on by the branches. The first-year shoots 

 are strongly branched and geniculate at the nodes, and their 

 branches of the later (1 23) sequences are thorns which 

 bear a single flower. The plant forms a leafless thorny ball, 

 it can attain a height of 40 centimetres and has very long 

 roots. I have seen pieces several metres long, laid bare above 

 the sand, and although only fixed at one end they were 

 giving off fresh shoots. If the plant is buried the upper 

 branches grow 7 upwards through the sand. 



Convolvulus eremophilus has a similar structure, but it is 

 less strongly branched and less thorny. 



Euphorbia cheirolepis an annual plant with small, bright 

 green and glossy, spathulate and spiny toothed leaves belongs 

 to another type. The same green colour distinguishes the vig- 

 orous, broad-leaved and very thorny Cousinia annua which 



