''Exallosperma longiflora'' is a species of

flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. They include all forbs (flowering plants without a woody stem), grasses and grass-like plants, a vast majority of ...

belonging to the family

Rubiaceae The Rubiaceae are a family of flowering plants, commonly known as the coffee, madder, or bedstraw family. It consists of terrestrial trees, shrubs, lianas, or herbs that are recognizable by simple, opposite leaves with interpetiolar stipules ...

. It is a shrub

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found els ...

Madagascar Madagascar (; mg, Madagasikara, ), officially the Republic of Madagascar ( mg, Repoblikan'i Madagasikara, links=no, ; french: République de Madagascar), is an island country in the Indian Ocean, approximately off the coast of East Africa ...

. It is the sole species in genus ''Exallosperma''. ''Exallosperma longiflora'' is a shrub which grows up to 5 meters tall. It flowers in January and February, and fruits in April. It is known only from the northern tip of Madagascar in

Sava The Sava (; , ; sr-cyr, Сава, hu, Száva) is a river in Central and Southeast Europe, a right-bank and the longest tributary of the Danube. It flows through Slovenia, Croatia and along its border with Bosnia and Herzegovina, and finally t ...

and

Diana Diana most commonly refers to: * Diana (name), a given name (including a list of people with the name) * Diana (mythology), ancient Roman goddess of the hunt and wild animals; later associated with the Moon * Diana, Princess of Wales (1961–1997) ...

regions. It grows in lowland dry deciduous and semi-deciduous forest on limestone, from sea level to 450 meters elevation.De Block P, Rakotonasolo F, Ntore S, Razafimandimbison SG, Janssens S (2018) Four new endemic genera of Rubiaceae (Pavetteae) from Madagascar represent multiple radiations into drylands. ''PhytoKeys'' 99: 1-66. https://doi.org/10.3897/phytokeys.99.23713 The genus is distinguished within tribe

Pavetteae Pavetteae is a tribe of flowering plants in the family Rubiaceae and contains about 624 species in 9 genera. Its representatives are found from the tropics and subtropics of the Old World and the southern Pacific region. Genera Currently acce ...

by pollen with psilate tectum, and by fruit with two stony

pyrene Pyrene is a polycyclic aromatic hydrocarbon (PAH) consisting of four fused benzene rings, resulting in a flat aromatic system. The chemical formula is . This yellow solid is the smallest peri-fused PAH (one where the rings are fused through mor ...

s. Each pyrene contains a laterally flattened ovoid seed with irregularly distributed surface ridges. The ridges are formed by elongation of the outer layer (exotesta) cells.

References

{{Taxonbar, from1=Q94152766, from2=Q95985464 Pavetteae Monotypic Rubiaceae genera Endemic flora of Madagascar Flora of the Madagascar dry deciduous forests Plants described in 2018