Anonymous: In addition to the native species, the cultivated coffees are wodely grown in Madagascar, both "Arabica" C. arabica L. and "Robusta" C. canephora Pierre ex A.Froehner and, according to Perrier de la Bâthie H (Les plantes introduites à Madagascar. Rev. Bot. Appl. et Agric. Trop. 11-12: 719-729, 833-837, 920-932, 990-999, 48-52, 128-133, 213-220, 296-301, 372-383, 462-468, 530-543) the less important C. congensis A. Froehner and C. liberica W. Bull ex Hiern.
C.M. Taylor, Nov 2013: This genus is characterized by its woody habit; leaves that often have domatia; interpetiolar or shortly sheathing, triangular, generally awned and persistent stipules; axillary, several-flowered, fasiculate to shortly cymose and subsessile inflorescences with the bracts usually fused in pairs; mostly four to five-merous, bisexual flowers; reduced to shortly developed truncate to lobed calyx limb; usually somewhat small, white, salverform corollas that are not densely bearded in the throat, and have the lobes contorted in bud; anthers withoutan apical appendage; two exserted linear stigmas; and fleshy, subglobose, drupaceous fruits that become red when mature and have 2 generally planoconvex, adaxially sulcate pyrenes with a rather thin wall. The a pair of opposite bracts or bracteoles that is fused creates the cupular structure called a calyculus, or sometimes a cupule (e.g, FTEA); calyculi are characteristic of Coffea and Tricalysia.
Davis et al. (2006) surveyed Coffea and found its largest center of species diversity is in Madagascar, with 61 endemic species here. They separated two subgenera: Coffea subg. Coffea is found throughout the range of the genus and comprises the majority of the species, while Coffea subg. Baracoffea is found only in dry western Madagascar (Mahajunga, Toliara) and comprises nine species. Coffea subg. Baracoffea was studied with molecular systematic data by Maurin et al. (2007), who found the species studied to form a monophyletic group nested within Coffea, and was studied taxonomically by Davis & Rakotonasolo (2008). This group was formally recognized as a subgenus by Davis et al. (2006), but was subsequently called the "Baracoffea alliance" in the formal taxonomy of Davis & Rakotonasolo (2008), who listed the formally published name Coffea subg. Baracoffea under this alliance designation but elsewhere in this article referred to this group as a subgenus. The nine species they included in this subgenus are Coffea ambongensis, Coffea bissetiae, Coffea boinensis, Coffea decaryana, Coffea grevi, Coffea humbertii, Coffea labatii, Coffea namorokensis, and Coffea pterocarpa.