Feb. 16, 1914 
Citropsis , an African Genus Allied to Citrus 
4 2 3 
CHARACTERS WHICH DISTINGUISH SPECIES OF CITROPSIS 
The principal diagnostic characters of the species of Citropsis are 
found in the flowers, leaves, and fruits. The size, shape, and propor¬ 
tions of the pistil and in particular of the style are of great importance. 
The smoothness or hairiness of the filaments and the shape of the ovary 
are also important characters, as is the length of the pedicel and peduncle 
in relation to the length of the pistil. The shape, size, and proportions 
of the leaflets, segments of the rachis, and petioles are not only obvious 
but necessary characters for use in distinguishing the species. Finally, 
the nature of the fruit, whether dry or pulpy, and if pulpy, whether 
juicy and sweet, or waxy, is useful in distinguishing the species. Owing 
to the number of species of Citropsis and the variability due to their 
wide range, it is usually necessary to have at least good flowers and 
leaves to be able to determine the species with any certitude, and in 
some cases fruits also are necessary. 
Inasmuch as none of the original descriptions of the African species 
of Limonia now referred to Citropsis included both flowers and mature 
fruits, it is obvious that it is a matter of much difficulty to determine the 
affinities of some of these species based on imperfect material. 
Citropsis Preussii (Engler), n. comb. 
Limonia Preussii Engler, 1895, in Notizbl. K. Bot. Gartens u. Mus. Berlin, Bd. 1, p. 28. 
Illus., Engler, 189s, in Engl, and Frantl, Pflanzenfam., T. 3, Abt. 4, p. 189, fig. 109, E-H. 
The following specimens 1 have been consulted: Kamerun. —Preuss (No. 548), 
September 19, 1890, Barombi Station on Elephanten See (Dahlem Herbarium 2 ; Kew 
Herbarium). Standt (No. 747), November 29, 1896, Johann Albrechtshbhe (Dahlem 
Herbarium, fragment in National Herbarium, Washington, D. C.; British Museum 
Herbarium). BttSGEN (No. 37), November 18, 1905, Johann Albrechtshohe (Dahlem 
Herbarium). Ledermann (No. 1455), December 1, 1908, Bare (Dahlem Herbarium; 
fragment in National Herbarium, Washington, D. C.). 3 
The type of the genus, Citropsis Preussii, was first collected by Preuss at 
Barombi Station on the south shore of Elephanten See in Kamerun on 
September 19,1890. Of his original collection (No. 548) three specimens, 
all showing good flowers, have been studied by the writers. (See fig. 3.) 
Two of these are preserved in the herbarium at Dahlem, near Berlin. 
The third was sent to Kew Gardens (April, 1894) before the species was 
published and evidently was not used by Prof. Engler in drawing up the 
original description, as the species is described as having trifoliate leaves, 
while those of the Kew specimen are 5-foliate. 
Besides this original material there are three excellent sheets in the 
Dahlem Herbarium and one at South Kensington of material collected 
by Standt (No. 747) on November 29, 1896, at Johann Albrechtshohe, 
1 All of the specimens cited from European herbaria were photographed by one of the writers in 1911-12, 
and prints enlarged to natural size have been filed in the National Herbarium at Washington, D. C. 
2 The sheet to which the original label is attached is the type specimen. 
3 Eedermann’s specimens have been designated "Limonia Preussii Engl., var. micrantha Engl./’ but it 
is probable that the very small flowers are due to a diseased condition of the plant and do not constitute a 
true varietal difference. 
