Feb. 16, 1914 
Citropsis , an African Genus Allied to Citrus 
421 
That the African species of Limonia constituting the section Citropsis 
are related to Citrus rather than to the Asiatic species of Limonia is a 
conclusion, based at first on a study of herbarium and living material, 
that has since been confirmed in gratifying manner by the results of 
experiments in grafting, which show that the African species belonging 
to the section Citropsis can be budded easily and grow well on all the 
commonly cultivated species of Citrus. 
TECHNICAL DESCRIPTION OF CITROPSIS 
It seems necessary to establish a new genus to include these African 
cherry oranges. This is best done by raising to generic rank the section 
Citropsis of Engler. 1 2 
Citropsis (Engler) Swing, and M. K. 
The genus Citropsis resembles Citrus in the general structure and appearance of 
the flowers and fruit, as well as in the texture, venation, and general type of the 
leaves. It differs from Citrus in having 4- or rarely 5- merous ovaries, with only a 
single ovule in each cell; fruits with sessile pulp vesicles which are broad at the bases 
where they are embedded in the endocarp; the stamens only twice as numerous as 
the petals; large compound leaves; and spines usually occurring in pairs. The leaves 
are odd pinnate, 5- or rarely 7-foliate, trifoliate, or sometimes unifoliate, subcoriaceous, 
pellucid punctate. The spines are paired or single in the axils of the leaves. The 
flowers occur in few- or many-flowered axillary clusters and are perfect, 4- or rarely 5- 
merous. The stamens are twice as numerous as the petals, free but flattened, and 
arranged to form a staminal tube surrounding the pistil much as in Citrus. The disk 
subtends and is slightly larger than the base of the ovary. The ovaries are 4- rarely 
5-celled with one ovule in [each cell. The style is long and deciduous; the stigma 
is large, subglobose, more or less 4- rarely 5-lobed. The fruit is globular or sub- 
globular, small (2 to 3 cm. in diameter), with a fleshy skin like that of a lime, dotted 
with oil glands. The pulp is vesicular, either sweet and edible or waxy. The pulp 
vesicles are not stalked as in Citrus, but are broad at the base where they are embedded 
in the endocarpic lining of the cells and taper gradually toward the pointed tips. In 
some species they are full of juice, in some they contain a waxy substance, and in 
some they dry up as the fruit develops. The seeds are large, 10 by 6 by 4 mm., with 
a hard, parchmentlike testa having a foramen at the tip. The cotyledons remain 
hypogeous in germination. The first two foliage leaves are opposite, as in Citrus. 3 
(See fig. 2.) 
1 Citropsis, gen. nov. (Limonia, § Citropsis, Engler).—Genus Citro affinis, foliis pinnatis, staminibus 
paudoribus (staminum numero petalorum duplo nunquam quadruplo), ovariis 4- rarius 5- locularis, 
loculis monospermis. 
Folia imparipinnata, trifoliata vel rarius unifoliata, subcoriacea, pelluddo-punctata. Spinae in axillis 
foliorum geminae vel singulae. Paniculae axillares, pauciflores. Flores hermaphroditi, 4- vel rarius 5- 
meri. Stamina 8 vel 10 (numero petalorum duplo). Discus ovarii basim subtendens. Ovarium 4- vel 
rarius 5- locularis, stylus longus, deciduus, stigma plus minusve quadrilobum, ovulo in loculo singulo. 
Fructus globosus vel subglobosus, cortice ut in Citro carnoso, glandulis oieiferis instructo, pulpa vesiculari, 
duld et eduli, vel cerea, vesiculis fusiformibus, ad basin in endocarpio immersis. Semina tnagna, testa 
dura, pergamena, foraminea. Cotyledones in germinatione hypogaeae. 
Arbor parva vel arbuscula, spinosa. 
Species typica, Limonia Preussii Engler. 
2 In Citropsis Schweinfurthii the first two postcotyledonary leaves are opposite, broadly oval, and short 
stalked; the next two or three leaves are simple, with short petioles; then follow unifoliate leaves with 
winged, longer petioles; then trifoliate leaves; and finally pinnately 5-foliate leaves. (See fig. 2.) 
