Aeschynomene sensitiva Sw.

Code

AESSE

Growth form

Broadleaf

Biological cycle

Annual to perennial

Habitat

Marshland

Global description
 
Aeschynomene sensitiva is a sub-shrub, woody at the base, annual or perennial, with an average height of 1 to 2 m. The stem is more or less covered with small asperities or stiff bristles especially at the ends. Leaves are alternate, paripinnately compound, consisting of a large number of leaflets, up to 23 pairs. The leaflets are glabrous, with asymmetrical base and marked with one projecting venation on the underside. Axillary inflorescences consist of 2 to 10 yellow papilionaceous flowers and standard striated with dark red on the underside. The fruit is an articulated pod, straight or slightly curved, whose surface has a short and loose pubescence that can be practically zero. The kidney-shaped seed is smooth and brown in colour.
 
Cotyledons
 
The cotyledons are sessile. The lamina is kidney-shaped, with rounded, smooth, glabrous base and apex.
 
First leaves
 
The first leaves are alternate, paripinnately compound.
 
General habit
 
Sub-woody plant, erect, annual or perennial, with flexuous, slightly sticky branches, measuring in average 1 to 2 m tall, exceptionally up to 5 m.
 
Underground system
 
The plant has a taproot system.
 
Stem
 
The stem is generally dark purple in colour. It is dotted with white spots in the seedling stage and small warts topped with short hairs when it gets older. The branches have a swollen base. They are glabrous or sparsely hairy.
 
Leaf
 
The leaves are alternate, compound, paripinnate. They measure 2 to 10 cm long. Their base is framed by two appendiculate deciduous stipules, narrow, ovate oblong, 3 to 15 mm long and 1 to 2.5 mm wide, extending below the attachment point by an appendix of 1 to 4 mm long. The leaf consists of 5 to 23 pairs of leaflets, usually well opposite, linear oblong, with asymmetrical base, rounded to apiculate apex., measuring 4-15 mm long and 1-4 mm wide, uninervate with a single projecting rib on the underside, glabrous.
 
Inflorescence
 
The flowers are grouped by 2-10 axillary inflorescence of 2 to 10 cm long.
 
Flower
 
The flower is 7 to 8 mm long with a floral stalk of 2 to 5 mm. The calyx is 3.5 to 4 mm long. It is glabrous, whole-lips. The corolla is yellow. The upper petal or standard measures 7-8 mm long. It is heavily streaked with dark red on its lapel. The keel is curved, shorter than the standard, yellow in colour.
 
Fruit
 
The fruit is an articulated pod, straight or slightly curved, 3 to 5 cm long and 5 mm wide. It is consist of 7 to 10 subrectangular articles measuring 3 to 5 mm long and 3-4 mm wide. Its surface is covered with a short pubescence in varying intensity (loose almost hairless). Articles are nervate, smooth the edges, warty in the center. This pod is often purplish on one side. It darkens as it dries.
 
Seed
 
The kidney shaped seed is 3 to 4 mm long and 2.5 to 3 mm wide. It is smooth, brown in colour.

Madagascar: A. sensitiva can bloom throughout the year, but especially during the period of February to September.

Aeschynomene sensitiva is an annual to perennial species. It reproduces by seeds. The seeds that remain in the articles of dried fruits are spread by water and tillage tools.

Comparaison des Aeschynomene

	A. indica	A. americana	A. sensitiva
Stem (pilosity)	glabrous	hairy	pubescent at the ends
leaflet (venation)		2 to 5 protruding ribs	1 protruding vein
Flower (colour)	yellow	pink	yellow veined with red
Fruit (colour)	fruit does not blackened	fruit does not blackened	fruit blackened when dried
Habitat (medium)	Hydromorphic environment	dewatered environment	hydromorphic environment

Aeschynomene sensitiva is a plant of swamps and marshy meadows.

Madagascar: A. sensitiva grows in moist alluvial soils and hydromorphic soil, in marshy meadows, the edges of canals and rice fields. It is a weed occurring in rice cultivation of plains without water up to 1200 m altitude on fairly fertile soil in sunny or slightly shady areas in extensive or semi-intensive cultivation system. This species occurs in areas of the East Coast, Northwest, West, Middle East and Middle West in Madagascar. It is also present in anthropic areas and in freshwater marshes between 0 and 1500 m of altitude, in the provinces of Antananarivo, Mahajanga, Toamasina, and Toliara.
Mauritius: Species naturalized and widespread in marshy stations of low altitudes.
Reunion: Absent.

Origin
 
Aeschynomene sensitiva is native to tropical America.
 
Worldwide distribution

It is present in Central and South America, tropical Africa, South-West Indian Ocean islands. It was introduced in the nineteenth century in Mauritius.

Overall harmfulness

Aeschynomene sensitiva is a species of marshy and flooded areas. This is a weed typical of irrigated rice fields.
 
Local harmfulness
 
Ivory Coast: rare and scarce.
Ghana: frequent and scarce.
Madagascar: A. sensitiva is an infrequent and often scarce weed species in crops. It is characteristic of rice fields without control of water and marshy places. The control of this species presents no particular difficulty except for the size of the species when the intervention is too late. Sometimes A. sensitiva may be locally harmful in rice cultures in lowland with random irrigation (case of rice cultures located downstream of the growing areas of Lake Alaotra).
Mali: rare but abundant when present.
Mauritius:
Nigeria: rare but abundant when present.
Reunion: absent.
Senegal: frequent and scarce.

Medicinal: A. sensitiva is a medicinal plant used in traditional medicine to facilitate birth when it get difficult. Decoction associated with Ocimum gratissimum and ageratum conyzoides, it is very used to the female toilet after giving birth.

Global control

For recommandations of weeding of irrgated and lowland rice in Africa, visit
 
For weeding Advice broadleaf annual weeds of irrigated rice and lowland in Africa, visit: 
http://portal.wikwio.org/document/show/20
For weeding Advice broadleaf perennial weeds in irrigated rice and lowland in Africa, visit: 
http://portal.wikwio.org/document/show/26
 
Local control
 
Madagascar: In Lake Alaotra, in flooded or in more or less random irrigation rice cultures, this species is controlled by spreading of late post-emergence herbicides such as 2,4-D; in other regions, it is eliminated by manual weeding.

Herbarium pictures ReCOLNAT: https://explore.recolnat.org/search/botanique/simplequery=Aeschynomene%2520sensitiva