''Uvariopsis congensis'' is a species of

plant Plants are the eukaryotes that form the Kingdom (biology), kingdom Plantae; they are predominantly Photosynthesis, photosynthetic. This means that they obtain their energy from sunlight, using chloroplasts derived from endosymbiosis with c ...

in the

Annonaceae The Annonaceae are a Family (biology), family of flowering plants consisting of trees, shrubs, or rarely lianas commonly known as the custard apple family or soursop family. With 108 accepted genera and about 2400 known species, it is the largest ...

family. It is native to

Angola Angola, officially the Republic of Angola, is a country on the west-Central Africa, central coast of Southern Africa. It is the second-largest Portuguese-speaking world, Portuguese-speaking (Lusophone) country in both total area and List of c ...

Cameroon Cameroon, officially the Republic of Cameroon, is a country in Central Africa. It shares boundaries with Nigeria to the west and north, Chad to the northeast, the Central African Republic to the east, and Equatorial Guinea, Gabon, and the R ...

, the

Central African Republic The Central African Republic (CAR) is a landlocked country in Central Africa. It is bordered by Chad to Central African Republic–Chad border, the north, Sudan to Central African Republic–Sudan border, the northeast, South Sudan to Central ...

, the

Democratic Republic of the Congo The Democratic Republic of the Congo (DRC), also known as the DR Congo, Congo-Kinshasa, or simply the Congo (the last ambiguously also referring to the neighbouring Republic of the Congo), is a country in Central Africa. By land area, it is t ...

Gabon Gabon ( ; ), officially the Gabonese Republic (), is a country on the Atlantic coast of Central Africa, on the equator, bordered by Equatorial Guinea to the northwest, Cameroon to the north, the Republic of the Congo to the east and south, and ...

Ivory Coast Ivory Coast, also known as Côte d'Ivoire and officially the Republic of Côte d'Ivoire, is a country on the southern coast of West Africa. Its capital city of Yamoussoukro is located in the centre of the country, while its largest List of ci ...

Kenya Kenya, officially the Republic of Kenya, is a country located in East Africa. With an estimated population of more than 52.4 million as of mid-2024, Kenya is the 27th-most-populous country in the world and the 7th most populous in Africa. ...

Sudan Sudan, officially the Republic of the Sudan, is a country in Northeast Africa. It borders the Central African Republic to the southwest, Chad to the west, Libya to the northwest, Egypt to the north, the Red Sea to the east, Eritrea and Ethiopi ...

Uganda Uganda, officially the Republic of Uganda, is a landlocked country in East Africa. It is bordered to the east by Kenya, to the north by South Sudan, to the west by the Democratic Republic of the Congo, to the south-west by Rwanda, and to the ...

Zambia Zambia, officially the Republic of Zambia, is a landlocked country at the crossroads of Central Africa, Central, Southern Africa, Southern and East Africa. It is typically referred to being in South-Central Africa or Southern Africa. It is bor ...

. Walter Robyns and

Jean Ghesquière Jean may refer to: People * Jean (female given name) * Jean (male given name) * Jean (surname) Fictional characters * Jean Grey, a Marvel Comics character * Jean Valjean, fictional character in novel ''Les Misérables'' and its adaptations * Jean ...

, the botanists who first

formally described A species description is a formal scientific description of a newly encountered species, typically articulated through a scientific publication. Its purpose is to provide a clear description of a new species of organism and explain how it differ ...

the species, named it after the Belgian Congo, now called the

, where the specimen they examined was collected in the town of

Kisantu Inkisi, more commonly known as Kisantu, is a town in the western Democratic Republic of Congo, lying south west of Kinshasa, on the Inkisi River. It is known for its large cathedral and for its botanical garden, which includes an arboretum of i ...

near the

Inkisi River The Inkisi River (, French: ''Rivière Inkisi'') is the last (closest to the rivermouth) of the larger tributaries of the great Congo River, being the first south bank (left side) tributary, located in Western Central Africa. The township of Zon ...

Description

It is a shrub or small tree reaching 5 meters in height. The branches are hairless and dark-colored. Its elliptical to narrowly oblong, sickle-shaped, papery leaves are 7.5-14 by 2-6 centimeters. The leaves have rounded to wedge-shaped bases and tapering tips. The leaves are hairless, or become hairless at maturity, and dark green. The leaves have 10-12 pairs of secondary veins emanating from their midribs. The secondary veins arch and connect near the margins of the leaves. Its petioles are 2-3 millimeters long, and hairless, with a groove on their upper side. Its solitary

Inflorescence In botany, an inflorescence is a group or cluster of flowers arranged on a plant's Plant stem, stem that is composed of a main branch or a system of branches. An inflorescence is categorized on the basis of the arrangement of flowers on a mai ...

s occur on branches and the trunk. Each inflorescence has 1 flower. Each flower is on a

pedicel Pedicle or pedicel may refer to: Human anatomy *Pedicle of vertebral arch, the segment between the transverse process and the vertebral body, and is often used as a radiographic marker and entry point in vertebroplasty and kyphoplasty procedures ...

. The pedicels have a pair of basal

bract In botany, a bract is a modified or specialized leaf, associated with a reproductive structure such as a flower, inflorescence axis or cone scale. Bracts are usually different from foliage leaves in size, color, shape or texture. They also lo ...

s that are covered in silky-brown hair. Its flowers are unisexual. The male flowers are on 4-5 millimeter long pedicels that are positioned at leaf

axils A leaf (: leaves) is a principal appendage of the stem of a vascular plant, usually borne laterally above ground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", while the leaves, stem, f ...

on branches. Male flowers have two rounded sepals that are 2 millimeters wide with silky hairs. Male flowers have 4 petals in a single

whorl A whorl ( or ) is an individual circle, oval, volution or equivalent in a whorled pattern, which consists of a spiral or multiple concentric objects (including circles, ovals and arcs). In nature File:Photograph and axial plane floral diagra ...

. The petals are narrowly elliptical, 6 by 3 millimeters and covered in brownish silky hairs. Male flowers have numerous, small, rectangular

stamen The stamen (: stamina or stamens) is a part consisting of the male reproductive organs of a flower. Collectively, the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament ...

s that are 0.5 millimeters long and consist of an anther without a stalk (filament). The female flowers are on 6-10 millimeter long pedicels that are positioned on the trunk and at leaf axils on branches. Female flowers have two rounded to slightly pointed sepals that are 2 millimeters wide with sparse, brown, soft hairs on their outer surface. Female flowers have 4 petals in a single whorl. The petals are opal to pointed, and 5 by 7 millimeters. The petals are covered in pale grey hairs on their outer surface and are hairless on their inner surface. Female flowers have numerous

carpels Gynoecium (; ; : gynoecia) is most commonly used as a collective term for the parts of a flower that produce ovules and ultimately develop into the fruit and seeds. The gynoecium is the innermost whorl of a flower; it consists of (one or more) ...

that are 3-3.5 millimeters long. The carpels have short, 0.5 by 0.6 millimeter, black stigmas that have dense, silky hairs. The fruit occur in clusters of 4-6 on pedicles that are 10-15 millimeters long. The fruit are cylindrical, constricted between the seeds, and 3.8-4.5 by 1.2-1.5 centimeters. Each fruit has 4-6 seeds in two rows. The seeds are 10-13 by 6-7 millimeters.

Reproductive biology

The pollen of ''U. congensis '' is shed as permanent tetrads.

Distribution and habitat

It has been observed growing gallery forests.

Uses

Bioactive compounds extracted from its bark, including

acetogenin Acetogenins are a class of polyketide natural products found in plants of the family Annonaceae. They are characterized by linear 32- or 34-carbon chains containing oxygenated functional groups including hydroxyls, ketones, epoxides, tetrahyd ...

s, have been reported to be

cytotoxic Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are toxic metals, toxic chemicals, microbe neurotoxins, radiation particles and even specific neurotransmitters when the system is out of balance. Also some types of dr ...

in tests with cultured human tumor cells.

References

{{Taxonbar, from= Q15367616 congensis Plants described in 1933 Flora of Angola Flora of Cameroon Flora of the Central African Republic Flora of the Democratic Republic of the Congo Flora of Gabon Flora of Ivory Coast Flora of Kenya Flora of Sudan Flora of Uganda Flora of Zambia Taxa named by Frans Hubert Edouard Arthur Walter Robyns Taxa named by Jean Hector Paul Auguste Ghesquière