Mezoneuron angolense (PROTA)

Plant Resources of Tropical Africa Introduction

List of species

Mezoneuron angolense Welw. ex Oliv.

Protologue: Fl. trop. Afr. 2: 261 (1871).

Family: Caesalpiniaceae (Leguminosae - Caesalpinioideae)

Synonyms

• Caesalpinia angolensis (Welw. ex Oliv.) Herend. & Zarucchi (1990).

Origin and geographic distribution

Mezoneuron angolense is distributed in West, Central, East and southern Africa.

Uses

In DR Congo the bark is sometimes used for making cordage, although more recent reports from eastern DR Congo indicate that the plant is viewed as useless and troublesome because of its prickles. The plant is sometimes considered to have ornamental value.

Botany

Liana up to 20 m long; stems 4–8 cm in diameter, sparsely hairy to almost glabrous, armed with scattered downwardly hooked prickles up to 11 mm long, which on older stems become enlarged and raised on subconical-cylindrical corky bosses up to 2 cm long and 1.5 cm in diameter. Leaves alternate, bipinnately compound with 4–10 pairs of opposite pinnae 4–8 cm long, each with 4–9 pairs of leaflets; stipules very small, caducous; petiole and rachis together (6–)10–30 cm long, rachis with paired hooked prickles, especially at base of pinnae; leaflets opposite, elliptical-oblong, (6–)10–28(–35) mm × (4–)6–15(–19) mm, the terminal ones usually broadly obovate and slightly larger, base rounded and oblique, apex rounded to emarginate, glabrous except usually on the midvein beneath and often also the basal part of the lower surface. Inflorescence a terminal or lateral raceme 5–40 cm long, simple or branched, hairy, many-flowered; bracts linear-triangular, 4–5 mm long, early caducous. Flowers bisexual, zygomorphic, 5-merous; pedicel 4–11 mm long; sepals imbricate, the lower one curving upwards over the others, unequal, oblong, 5–9 mm × 3–4 mm, hairy; petals imbricate, 6.5–9 mm × 5.5–7.5 mm, the lamina suborbicular and clawed, yellow or greenish yellow; stamens 10, alternately long and short, longest ones 13–17 mm long; ovary superior, 1-locular. Fruit an elliptical-oblong to narrowly elliptical, flattened pod 6.5–14.5 cm × (2–)2.5–4.5 cm including the large membranous wing on the upper margin, indehiscent, with the persistent receptacular disc forming a collar round the base, red-brown to brown-black, leathery, (1–)2–4(–5)-seeded. Seeds elliptical to oblong, compressed, 5–9 mm × 2.5–7 mm, smooth, blackish. Seedling with hypogeal germination.

Mezoneuron comprises about 20 species, mostly in tropical Asia and extending into Australia and Polynesia, with 2 species in mainland tropical Africa and 2 in Madagascar. It is sometimes included in Caesalpinia as subgenus Mezoneuron, but is distinguished by the thin, winged pods.

Ecology

Mezoneuron angolense occurs from near sea-level up to 2000 m altitude, in rainforest, riverine and swamp forests, secondary forest, forest margins, coastal evergreen bushland, thickets, savanna, and along roads.

Genetic resources

In view of its wide distribution and occurrence in a wide range of habitats, including disturbed ones, Mezoneuron angolense is not threatened by genetic erosion.

Prospects

Although Mezoneuron angolense is widely distributed in tropical Africa, records of it being used as a fibre plant are scarce, and contradicted by other sources characterizing the plant as useless and troublesome. Therefore, the prospects of this plant seem very limited.

Major references

• Brenan, J.P.M., 1967. Leguminosae, subfamily Caesalpinioideae. In: Milne-Redhead, E. & Polhill, R.M. (Editors). Flora of Tropical East Africa. Crown Agents for Oversea Governments and Administrations, London, United Kingdom. 230 pp.

• Brummitt, R.K., Chikuni, A.C., Lock, J.M. & Polhill, R.M., 2007. Leguminosae, subfamily Caesalpinioideae. In: Timberlake, J.R., Pope, G.V., Polhill, R.M. & Martins, E.S. (Editors). Flora Zambesiaca. Volume 3, part 2. Royal Botanic Gardens, Kew, Richmond, United Kingdom. 218 pp.

• Wilczek, R., Léonard, J., Hauman, L., Hoyle, A.C., Steyaert, R., Gilbert, G. & Boutique, R., 1952. Caesalpiniaceae. In: Robyns, W., Staner, P., Demaret, F., Germain, R., Gilbert, G., Hauman, L., Homès, M., Jurion, F., Lebrun, J., Vanden Abeele, M. & Boutique, R. (Editors). Flore du Congo belge et du Ruanda-Urundi. Spermatophytes. Volume 3. Institut National pour l’Étude Agronomique du Congo belge, Brussels, Belgium. pp. 234–554.

Other references

• d’Oliveira Feijão, R., 1963. Elucidário fitológico. Plantas vulgares de Portugal continental, insular e ultramarino. Classificão, nomes vernáculos e aplicações. Volume 3, P-Z. Instituto Botânico de Lisboa, Lisbon, Portugal. 394 pp.

• Medina, J.C., 1959. Plantas fibrosas da flora mundial. Instituto Agronômico Campinas, Sao Paulo, Brazil. 913 pp.

• Missouri Botanical Garden, undated. VAST (VAScular Tropicos) nomenclatural database. [Internet] http://mobot.mobot.org/ W3T/Search/ vast.html. March 2010.

• Yamada, T., 1999. A report of the ethnobotany of the Nyindu in the eastern part of the former Zaire. African Study Monographs 20(1): 1–72.

Author(s)

• M. Brink, PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article

Brink, M., 2010. Mezoneuron angolense Welw. ex Oliv. [Internet] Record from PROTA4U. Brink, M. & Achigan-Dako, E.G. (Editors). PROTA (Plant Resources of Tropical Africa / Ressources végétales de l’Afrique tropicale), Wageningen, Netherlands. <http://www.prota4u.org/search.asp>.

Accessed 18 December 2024.

• See the Prota4U database.