when considered of specific rank. When reduced to va- 
rietal rank, the earliest epithet applied in the new rank is 
Adansoniana Dubard. Under the Rules this must be 
adopted rather than either adstringens or Adansoni. 
Acacia Orrota (Forsk.) Schweinfurth 
(4. nubica Bentham) 
Bentham described Acacia nubica as a new species in 
1842. In 1896, Schweinfurth pointed out that Forskal 
had described the same plant in 1775 as Mimosa 6rfota. 
Following the rule of priority Schweinfurth made the 
correct combination Acacia Orfota (Forsk.) Schwein- 
furth, a name which seems to have been rather generally 
overlooked by botanists. 
Acacia Orfota (Porsk.) Schweinfurth in Bull. 
Herb. Boiss. 4, App. 2 (1896) 213. 
Mimosa brfota Forskal FI]. Aegypt.-Arab. (1775) 177. 
Acacia nubica Bentham in Hooker London Journ. 
Bot. 1 (1842) 498. 
Acacta Rappiana G. Savi 
(A. tortilis Hayne) 
In northern and northeastern Africa there occur two 
closely related acacias with spirally twisted legumes 
which have been passing as Acacia tortilis Hayne and 
Acacia spirocarpa Hochstetter ex A. Richard. The former 
is a species ranging from the Anglo-Egyptian Sudan, 
across the Libyan and Nubian deserts to the French Su- 
dan, Senegambia and northern Nigeria. The latter occurs 
in Arabia, Nubia, the Anglo-Egyptian Sudan, Eritrea, 
Tanganyika and Kenya. Burtt-Davy, in discussing these 
two species (in Kew Bull. 1930: 402), states that they 
may represent two species which have hybridized, or an 
aggregate species with a tendency to geographic segre- 
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