Differentiating Characteristics of Coffee Beans, in Cross-section
Col. I. Mature bean. Col. II. Embryo.
A. Coffea arabica, R. Coffea robusta, L. Coffea liberica
Among the allied Liberian species Dr. Cramer recognizes:
Abeokutæ, having small leaves of a bright green, flower buds often pink just before opening (in Liberian coffee never), fruit smaller with sharply striped red and yellow shiny skin, and producing somewhat smaller beans than Liberian coffee, but beans whose flavor and taste are praised by brokers;
Dewevrei, having curled edged leaves, stiff branches, thick-skinned berries, sometimes pink flowers, beans generally smaller than in C. liberica, but of little interest to the trade;
Arnoldiana, a species near to Coffea Abeokutæ having darker foliage and the even colored small berries;
Laurentii Gillet, a species not to be confused with the C. Laurentii belonging to the robusta coffee, but standing near to C. liberica, characterized by oblong rather than thin-skinned berries;
Excelsa, a vigorous, disease-resisting species discovered in 1905 by Aug. Chevalier in West Africa, in the region of the Chari River, not far from Lake Tchad. The broad, dark-green leaves have an under side of light green with a bluish tinge; the flowers are large and white, borne in axillary clusters of one to five; the berries are short and broad, in color crimson, the bean smaller than robusta, very like Mocha, but in color a bright yellow like liberica. The caffein content of the coffee is high, and the aroma is very pronounced;
Dybowskii, another disease-resisting variety similar to excelsa, but having different leaf and fruit characteristics;
Lamboray, having bent gutter-like leaves, and soft-skinned, oblong fruit;