Macrotyloma

Seeds of horse bean ( Macrotyloma uniflorum )

Macrotyloma is a plant genus in the subfamily of the Fabaceae ( Faboideae ) within the legume family ( Fabaceae ). The botanical genus name Macrotyloma is from the Greek words macros for large and Tylos for bead derived callus. There are about 24 Macrotyloma species. It is one of the genres of Faboideae whose types are called beans.

Description

Macrotyloma species grow as creeping or climbing, rarely self- erect, annual or perennial herbaceous plants. They are not armed with spines or thorns. The alternate on the stem are arranged distributed leaves are petiolate and usually pinnately three-part, rarely only one part leaf is formed. There are Stipules present.

The flowers are individually up to a few tufted summarized in the leaf axils or in pendant, composite racemose inflorescences. There are bracts, and bracts present.

The hermaphrodite flowers are zygomorphic and four or fünfzählig. The four or five unequal sepals are fused with two cup lips. The upper calyx lip consists of two sepals that are fused completely or partially; the lower calyx lip consists of two to three sepals; the calyx teeth are shorter than the calyx tube. The corollas possess the typical structure of the butterfly flower. The five nailed petals are glabrous, whitish - greenish- yellow to yellow, sometimes with reddish- purple drawing. The flag is not spurred but auriculate and has two long appendages. The flag is more than wings and keel. The wings are narrow and the boat is straight. The ten fertile stamens are not fused with the petals. Nine stamens are fused into a tube. All anthers are equal. The individual upper permanent carpels contain three to 13 ovules. The thread-like, curved stylus is hairy. The scar is capitate.

It formed the legumes. Only when Erdbohne ( Macrotyloma geocarpum ), the legumes are in the ground, similar to the peanut ( Arachis hypogaea ) and bambara groundnut ( Vigna subterranea ). The legumes are just curved up and non-septate between the seeds. The compressed seeds usually do not have an aril, but a white hilum. The distribution unit ( diaspore ) is the seed.

Use

Some species are cultivated for food production: Erdbohne ( Macrotyloma geocarpum ) and horse beans ( Macrotyloma uniflorum ).

Since they fix nitrogen ( Rhizobium root nodules ) they are important for soil improvement.

Occurrence

The distribution area includes only the Old World. Almost all of their natural occurrence only in Afrike: in tropical Africa, Madagascar, the Mascarene Islands; only one species is native to the Indian subcontinent.

System

The genus belongs to the subtribe Macrotyloma Phaseolinae the tribe Phaseoleae in the subfamily Fabaceae ( Faboideae ) within the legume family ( Fabaceae ). The first description of the genus Macrotyloma was made in 1970 by Bernard Verdcourt in Kew Bull, 24:322 separated from the genus Dolichos L. these species in a group Macrotyloma Wight & Arn. were arranged, in Robert Wight & Arnott Walker Arnott George Prodr. Fl. Pen Ind. Or, was 248, in 1834 described. A synonym for Macrotyloma ( Wight & Arn. ) Verdc. is Kerstingiella Harms.

There are about 24 Macrotyloma species:

• Macrotyloma africanum ( Brenan ex R.Wilczek ) Verdc. ( Syn. Dolichos africanus Brenan ex R.Wilczek )
• Macrotyloma axillary ( E.Mey. ) Verdc. : Macrotyloma axillary var axillary ( syn. Dolichos axillaris E.Mey. )
• Macrotyloma axillary var glabrum ( E.Mey. ) Verdc. ( Syn. Dolichos axillaris var glaber E.Mey. )
• Macrotyloma axillary var macranthum ( Brenan ) Verdc. ( Syn. Dolichos axillaris var macranthus Brenan )

• Macrotyloma uniflorum var benadirianum ( Chiov. ) Verdc. ( Syn. Dolichos benadirianus Chiov. )
• Macrotyloma uniflorum var stenocarpum ( Brenan ) Verdc. ( Syn. Dolichos uniflorus var Stenocarpus Brenan )
• Macrotyloma uniflorum ( Lam.) Verdc. var uniflorum ( syn. Dolichos biflorus auct, Dolichos uniflorus Lam.. )
• Macrotyloma uniflorum verrucosum var Verdc.