ROBINIA 197 



t Spines in pairs, one on each flank of the 

 large and angular leaf-scar, sharp, rigid, 

 compressed or angular and slightly curved 

 upwards ; buds minute, 2 5 together, buried 

 in the prominent pulvinus. 



Robinia pseudacacia, L. Robinia, False Acacia (Fig. 

 99). The spines are stipules and persist for several years ; 

 but they may be absent. 



The twigs of Robinia are more or less 5-angular, brittle 

 and long, and with conspicuous lenticels. In the cavity 

 of the leaf-axil are really 2 5 superposed buds, minute, 

 naked, and walled in all round by the up-growing pubescent 

 margins of the petiolar base, which covers them entirely 

 except for a small aperture above : the uppermost bud 

 alone grows out as a rule, the lower may burst through 

 the tissues of the leaf-scar itself, which is more or less 

 shield-shaped, or trefoil-shaped, with 3 obscure leaf-traces. 

 Pith pentagonal, pale. Twigs olive or brown to bright 

 red-brown, passing to grey or slaty grey. 



Platanus and Philadelphus are the only others likely 

 to Qpcur in which the leaf-bud is totally invested by the 

 leaf-base, and they are easily differentiated, the former by 

 its prominent buds exposed when the leaf falls, the latter 

 by its opposite leaves and buds. 



ft Spines triple, or occasionally single, beneath 

 the small lunate leaf-scar and not flanking 

 it ; the leaf-scar subtends the single, promi- 

 nent pointed bud. 



Ribes Grossularia, L. Gooseberry (Fig. 100). The 

 spines are borne on the pulvinus of the leaf, and some- 

 times there are other prickles, more bristle-like and not 

 connected with the leaves, scattered along the internodes. 

 Buds with several distinct but narrow, loose, brownish. 



