134 
In 1906 Van Tieghem, on the other hand, divided Balanites into 
3 genera, comprising altogether 22 species. The three genera were 
Agialida, founded on Ximenia aegyptiaca; Agiella, founded on 
Balanites aegyptiaca var. angolensis; and Balanites, which Van 
Tieghem restricted to B. Roxburghii and its allies, although the 
type species of Delile’s genus Balanites was B. aegyptiaca. The 
three genera were distinguished as follows :— : 
Petals glabrous on their upper surface :— 
Ovary hairy ... : Agialida. 
Ovary glabrous ae ie .  Agiella. 
Petals hairy on their upper surface... .... - - Balanites. 
REVISION OF THE SERIES ROXBURGHIANAE., 
In the writer’s opinion the characters mentioned are hardly of 
sufficient importance to justify the creation of new genera, but 
there can be no question that they are extremely useful for dis- 
tinguishing groups of species. It is therefore proposed to recognize 
three series of species in Balanites, corresponding’to Van Tieghem’s 
three genera. Van Tieghem’s generic names are unfortunately 
inapplicable, as two of them, according to the view here adopted, 
apply to the whole genus. The series are therefore named in each 
case after the type species ; Aegyptiacae corresponding to Agialida ; 
Angolenses to Agiella ; and Roxburghianae to Balanites. The three 
groups have been styled ‘series’ instead of ‘ sections,’ as it is doubt- 
ful in the present state of our knowledge whether they constitute 
natural groups. 
The present investigation may be limited to the series Roxburghi- 
anae, as both B. Maugham and B. Dawei have petals hairy on the 
upper surface, and are therefore assignable to that group. The 
previously described species belonging to the Rozrburghianae-are : 
B. Roxburghii, Planch., B. Jacquemonti, Van Tiegh., B. indica, 
Van Tiegh., B. trifora, Van Tiegh., B. Wilsoniana, Dawe & 
Sprague, and B. Tieghemi, A. Chevalier. 
Balanites Jacquemonti, Van Tiegh., and B. indica, Van Tiegh., 
appear to be reducible to B. Roxburghii, Planch., the distinguishing 
characters mentioned by Van Tieghem being such as might be met 
with on branches of different age and at different seasons of the year. 
To give a single example, the leaves of B. Roxburghii described by 
Van Tieghem are old leaves of the spiny long-shoots; those of B. 
Jacquemonti are young leaves of the short-shoots ; whilst those of 
B. indica are old leaves of the short-shoots. 
Balanites triflora, Van Tiegh., appears, however, to differ specifi- 
eally from B. Roxburghii, although the character of the three-flowered 
cymes given by the author does not hold good. In B. Rovburghii 
the spines are strong and well-developed, and the short-shoots 
bearing the cymes are either cushion-like, or if the ow out, 
rarely exceed two inches in length. In B. triflora, on the other 
hand, the spines are short and slender, 3-4 in. long, and the flowering — 
shoots may attain a length of 6-8 inches. Even when it is borne in 
mind that fully grown trees of B. Rozxburghii are often unarmed 
(Beddome, Flora Sylvatica, vol. ii. p. 1.), the differences between B. 
Roxburghii and B. triflora seem sufficient to justify the retention 
of the latter as an independent species, os 
