Exostema acuminatum is a species of flowering plant in the family Rubiaceae. It is native to Hispaniola, and was described in 1903.
Exostema acuminatum is a shrub or tree with papery leaves, white flowers, and brownish-black capsule fruits. The wood is used for fuel, and the leaves are used to treat colds and flu-like symptoms. The IUCN lists the species as of Least Concern.
Taxonomy The species was described by Ignatz Urban in 1903. The type locality is near Gonaïves, Haiti.
Exostema acuminatum is a sister species of Exostema salicifolium. E. acuminatum may hybridise with Exostema caribaeum.
Distribution Exostema acuminatum is native to the wet tropical biome of Hispaniola (the Dominican Republic and Haiti). It mostly grows on the northern and southern coasts of Hispaniola. The species' estimated extent of occurrence is .
Exostema acuminatum grows in lowland, subtropical, and dry forests, reaching altitudes of up to . It can grow on limestone, and alluvial soil. The species grows in both disturbed and natural habitats.
Description Exostema acuminatum is a shrub or tree. It grows up to high. The branches are yellowish or grey.
The leaf stems are long. The leaves are papery, lanceolate to ovate-lanceolate, long, and wide. The primary vein is prominent on the upper surface.
The flower stems are long, and usually have a single flower. The hypanthium is long, and is oblong or elliptical-oblong. The calyx has five minute triangular lobes. The corolla is white, and long. The corolla tube is long, and around thick.
The fruits are brownish-black, elliptical-oblong capsules. The capsules are around long, and thick.
Uses Exostema acuminatum is used for charcoal and firewood. The leaves can be used to create a herbal-like tea, which is used to treat colds and flu-like symptoms.
Conservation In 2024, the IUCN assessed Exostema acuminatum as of Least Concern. The population is considered stable.
The species is present in protected areas of the Dominican Republic. It can compete with invasive species, including Neltuma juliflora. Exostema acuminatum may be threatened by the use of wood for fuel, and habitat loss caused by development and agriculture.
Names In Spanish, the species is known as or .
References