Ehretia
Content
Description
Trees or shrubs.
Leaves small to large, alternate, margin entire or serrate, sometimes wavy.
Inflorescences terminal and/or lateral, branched or unbranched, sometimes arranged in corymb- or panicle-like structures.
Stamens: anthers exserted as a rule, on filiform filaments.
Ovary: style terminal, with two branches free in the uppermost part or to the middle; stigmas 2, capitate or elongate.
Fruit a subglobose drupe, yellow, orange or reddish, with two separate pyrenes sometimes divided again into 4 one-seeded parts.
Distribution
About 50 species in the tropics and subtropics of Africa, Asia and Australia, 3 species in America. In Malesia 12 species.
Notes
Chromosome numbers given as 2n = 26, 32, 40.
Crystal druses present in vascular parenchyma.
The genera Ehretia and Bourreria are very close to each other. The latter generally has been regarded as exclusively American, but Thulin (1987) found that also some African species belong to it. The main distinguishing character is the calyx of the young bud which is undivided in Bourreria splitting into 2 to 5 lobes when opening, while 5 separate lobes are present from the beginning in true Ehretia. The pyrenes are always separating into two one-seeded units in Bourreria, while in Ehretia there are two sections, Ehretia s.str. with 2 two-seeded pyrenes not further dividing at maturity, and Bourreroides Benth. & Hook, f. with 4 separate units in the end.