66 SOUTH AFRICAN BOTANY 
mark the bases of the leaves of the Aloe ciliaris, and trace 
these marks round the stem, we find that the sixth leaf is 
exactly overthe first, and that the spiral goes exactly round 
the stem twice. The leaves are arranged, therefore, in five 
rows or ORTHOSTICHIES. This arrangement is spoken 
Fig. 40.—Shoot of Privet, showing Decussate Arrangement of Leaves. 
of as a phyllotaxy of 2. Similarly in the case of the 
Canna, the fourth leaf is over the first, thus forming 
three orthostichies, and we go round the stem once to 
reach this leaf. This arrangement is the } arrange- 
ment. 
The most common arrangements are 4, 4, 2, 3, 4, 
3, #4 etc. This series can easily be remembered, for 
in each fraction the numerator is the sum, of the numer- 
