Aeschynomene indica L.

Global description

Aeschynomene indica is a herbaceous plant, erect and branched, a little woody at the base, annual or perennial, which measures up to 2 m high. It is an entirely hairless plant. The cylindrical stem has a central core. The leaves are composed paripinnate and alternate of 15 cm maximum. They have a large number of small leaflets, up to 45 pairs, linear oblong, uninerved. Axillary inflorescences are composed of 1 to 4 yellow papilionaceous flowers often streaked with purple. The fruit is a flat linear pod, curved or straight, articulated in 5 to 10 quadrangular segments that separate separately. Each segment is indehiscent and contains a brown to black kidney-shaped seed.

Cotyledons

Cotyledons are glabrous. The petiole is 0.5 mm long. The uninerved lamina is asymmetrical, elliptic to oval, obliquely obtuse base, apex rounded. It measures 8.5 to 10.5 mm long and 5 to 6.5 mm wide.

First leaves

The first leaf is composed and glabrous, with broad stipules at its base. Its petiole is 2.5 to 3 mm long. It has 5 pairs of uninerved, elliptical leaflets with asymmetric obtuse base, apex apiculated, entire margin. They are 3.5 to 6 mm long and 1.5 to 2 mm wide.

General habit

Aeschynomene indica is an erect entirely hairless plant, annual to perennial, bushy, very ramified and often woody at the base, which measures 30 cm to 2 m in height.

Underground system

The root is a taproot.

Stem

The main stem is cylindrical in section, glabrous and warty at base, sometimes with swollen hairs at the base at the young stage. It can be swollen and slightly woody towards the base; it contains marrow in its central part and remains greenish while drying.

Leaf

The leaves are paripinnate and alternate, petiole 0.5 to 2 cm long and rachis 4 to 14 cm long. Uninhibited and glabrous leaflets, 10 to 45 pairs in length, are partially opposed. Shortly stalked, they present an oblong linear lamina, with asymmetrical base, obtuse short mucronate apex, entire margin. They are 2.5 to 10 mm long and 1.5 to 4 mm wide and are dark green on the upper side, light green on the underside. The base of the petiole is framed by 2 pointed oblong triangular oblong appendages prolonged under their insertion point. These stipules are rpidly caducous. They are 8 to 15 mm long.

Inflorescence

Axillary inflorescences consist of 1 to 4 pale yellow papilionaceous flowers. They measure 2.5 cm long maximum. The peduncle of the inflorescence bears a leaf that often has another raceme 3 to 8 cm long. The inflorescence has an oblong, pointed, finely toothed oval floral bract 1.5 to 4 mm long, which is deciduous. The pedicel is 1.5 to 6 mm long.

Flower

The flower is 5 to 7 mm long. The calyx 4 to 6 mm is bifid, composed of 2 short and unequal lobes (lobe less than 3 teeth), glabrous. The corolla consists of the upper or lower petal, obovate, yellow or whitish more or less striped or speckled with purple, with two lateral petals or wings, obtuse, yellow, of a lower petal or keel, about the same length as wings and yellow or greenish yellow. The 10 stamens are divided into 2 groups of 5, of the same size. The ovary is tuberculous, borne by a long foot. It is extended by a curved style.

Fruit

The fruit is a flat linear pod, scalloped on the lower side, curved to almost right, 25 to 50 mm long and 4 to 5 mm wide. Glandular hairy when young, it becomes glabrescent when ripe. It is not echinulate when ripe. It is divided into 5 to 10 indehiscent quadrangular articles with a lignified envelope, which stand out separately. They each contain one seed.

Seed

The kidney-shaped seed is 3 to 3.5 mm long and 2 to 2.5 mm wide. It is satin, brown to black.

Worldwide distribution

Aeschynomene indica is widespread in tropical Africa from Senegal to Ethiopia and from northern Somalia southward to the Transvaal and Namibia, throughout the South Sahelian and Sudanian ecozones and also on Sao Tome and Madagascar. Widespread also in tropical and subtropical Asia, Australia and North America. In Australia, it occurs as far south as northern New South Wales and the northern parts of the Flinders Ranges of South Australia. The North American material is often identified as A. evenia. However, Rudd (1959) states that the two are distinct species, both of which occur in North America.

https://www.gbif.org/species/2949250