CITROPSIS, A NEW TROPICAL AFRICAN GENUS ALLIED 
TO CITRUS 
By Walter T. Swingle, Physiologist in Charge , and Maude KELLERMAN, Botanical 
Assistant , Crop Physiology and Breeding Investigations , Bureau of Plant Industry 
INTRODUCTION 
Missionaries and pioneer explorers of equatorial Africa long ago re¬ 
ported the finding of wild oranges and wild lemons. If the fruits were 
green, they resembled small limes and lemons; if ripe, their sweet and 
agreeable flavor caused them to be classed as oranges. 
These fruits are from 2 to 3 cm. in diameter and are borne, two to five 
or more in a cluster, in the axils of the leaves. Because of this pecul- 
Fig. i. — Citropsis Schweinfurthii: A branch showing 3-foliate and 5-foliate leaves, leaflike petioles, and 
rachis segments; also paired and single spines in the axils of the leaves. From a plant in greenhouse of 
the Department of Agriculture grown from seed from Budongo Forest, Uganda, Africa. (C. P. B. No. 
2902.) One-fourth natural size. 
iarity they may be called African cherry oranges. The leaves are odd- 
pinnate, usually with five leaflets, but often trifoliate. The petioles and 
the segments of the rachis are so broadly winged that in some species 
they look not unlike leaflets. (See fig. i.) 
As early as 1870 Schweinfurth, the veteran African explorer, had col¬ 
lected leafy twigs of one of these plants, but no flowers or fruits, in the 
Vol. I, No. 5 
Feb. 16, 1914 
0-13 
Journal of Agricultural Research, 
Dept, of Agriculture, Washington, D. C. 
(419) 
