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EXTRA-TROPICAL SOUTH AFRICAN ACACIAE 
Trans. Linn. Soc. xxx) regards the spines of A. detinens, Burch., as prickles, 
but it has been proved by a series of transverse sections that these are 
true spines and not prickles. In A. spirocarpoides, Engl., there is greater 
variety than usual in the spines, for there occurs at the nodes either a pair 
of long straight white spines, or a pair of short recurved spines, or finally a 
long straight white spine with a short recurved spine. This species appears 
to me to be identical with the type specimen of A. heteracantha, Burch., in 
the Kew Herbarium. There is, however, no fruit of the latter at Kew and 
Burchell in his notes describes the legumes as “linear” and does not mention 
that they are spirally twisted. Both species are recorded from the same 
locality. 
The species, A. Karroo, Hayne, and A. natalitia, E. Mey., seem to be very 
closely related and, in the dried state, are extremely difficult to distinguish. 
There may be distinguishing characters in the shape and size of the trees, 
but this, however, I have not yet been able to ascertain. In herbarium 
specimens of A. natalitia, the bark of the branchlets is usually light grey or 
whitish, while that of A. Karroo is dark brown. For the present, I have kept 
the two species distinct. 
The same difficulty exists in the case of A. robusta, Burch., and A. clavigera, 
E. Mey., two very closely allied species. It is highly probable that A. clavi- 
gera may prove to be only a less robust form of A. robusta. 
I am greatly indebted to Dr Stapf and Mr Craib of the Royal Botanic 
Gardens, Kew, without whose guidance and generous assistance I should not 
have been able to undertake the work. 
Stipules not spinescent (foliaceous or membraneous) ; stems furnished with 
prickles. 
Erect trees ; inflorescence spicate. 
Prickles, when present, in pairs at the nodes ; ovary glabrous. 
4. caffra. 
Prickles, when present, scattered ; ovary pilose. 
Pinnae 6 — 10 jugate. 5. eriadenia. 
Pinnae 20 — 40 jugate. 6. ataxacantha. 
Climbing or scrambling shrubs ; inflorescence capitate. 
Pinnae 3 — 5 jugate, leaflets oblong 6 — 12 jugate. 7. Kraussiana. 
Pinnae 8 — 20 jugate, leaflets narrow linear, 30 — 35 jugate. 8. pennata. 
Stipules spinescent ; stems not furnished with prickles. 
Inflorescence spicate. 
Leaflets obliquely rotund, 15 — 3 cm. wide. 1. pallens. 
Leaflets oblong to linear, 0T — 0'5 cm. wide. 
Leaflets obliquely rotund, not more than 0’5 cm. wide, up to 6 jugate. 
2. Burkei. 
