Aulacocalyx pallens is a species of flowering plant in the family Rubiaceae. It is a tree with elliptical to obovate leaves, white flowers, and black fruits. The species is native to west-central Africa.
Aulacocalyx pallens was described in 1877, and is listed as Vulnerable by the IUCN.
Taxonomy Aulacocalyx pallens was described by William Philip Hiern in 1877, and initially placed in the genus Randia. In 1997, Diane Mary Bridson and Estrela Figueiredo moved it to the genus Aulacocalyx.
There are two recognised subspecies: Aulacocalyx pallens subsp. letestui - Native to the Democratic Republic of the Congo and Gabon Aulacocalyx pallens subsp. pallens - Native to São Tomé and Príncipe
Distribution Aulacocalyx pallens is native to the wet tropical biome of the Democratic Republic of the Congo, Gabon, and São Tomé. Its extent of occurrence is estimated as .
The species grows in mature and secondary forests, at elevations of .
Description Aulacocalyx pallens is a tree that grows up to high. The branches are striped, and covered with short, soft hairs. The leaves are elliptical to obovate, long, and wide. When dry, the leaves are olive, light green, or brown. The leaves have domatia. The leaf stems are long.
The inflorescences grow on stems, and usually have at least five flowers. The calyx tube is long, and has long lobes. The corolla is white, and long. The corolla has five elliptical to oblong lobes, which are long, and wide.
The fruits are wide, and black when dry. The seeds are long, around wide, and black when dry.
Conservation In 2020, the IUCN assessed Aulacocalyx pallens as Vulnerable. Some populations are threatened by agriculture. The species is present in Parque Natural Obô de São Tomé.
References