Bacopa crenata (Benth.) Hepper

Global description

Bacopa crenata is firstly prostrate then erect, rooting at lower nodes, measuring 10 cm to 1 m long, glabrous. The stem is spongy, the leaves are sessile and opposite, narrowly lanceolate, crenelate- serrated at the top, with a single midrib. White flowers, in tube, are usually solitary in the axils of the leaves. The fruit is a capsule containing numerous seeds.
 
General habit

Annual, glabrous plant, creeping then erect, rooted at the lower nodes. It measures between 10 cm and 1 m long.
 
Underground system

The taproot with few roots at the lower nodes.
 
Stem

The stem is spongy, with squarish section. It is glabrous and shiny.
 
Leaf

The leaves are simple, opposite and decussate. They are sessile, with elliptic lanceolate blade, base attenuate in acute corner, wedged apex, crenelate-serrated in the upper half. They measure 2 to 3.5 cm long and 5 to 11 mm wide. Venation is reduced to a central rib which is prominent on the upper face. Both sides are glabrous.
 
Inflorescence

The flowers usually solitary, are located in the leaf axils.
 
Flower
 
Pedicel and calyx are glabrous, unlike Bacopa floribunda whose pedicel and calyx are pubescent. The calyx consists of 5 free sepals of different form and appearance. They measure 7-8 mm long and 5-6 mm wide, with shortly ciliated margin. The dorsal sepal is enlarged oval, with cordate base, rounded obtuse apex, and is traversed by a network of ribs. The lateral sepals are narrow oval lanceolate, with rounded base, and narrowly acute apex. The ventral sepal is oval, rounded base and top. White flower with purple throat and veins, constitute of a tube terminated by two lips: the upper slightly bilobed, the lower, wider and deeply divided into three lobes. 4 stamens are inserted on the corolla tube. The superior ovary is extended by an elongated style ending in a bifid stigma.
 
Fruit
 
The fruit is a capsule. It contains many seeds.

Madagascar: Bacopa crenata can bloom all year round

Bacopa crenata is an annual or perennial plant that is propagated by seed and vegetatively. Small seeds are dispersed by water.

Bacopa crenata can easily be confused with Bacopa floribunda.

Species	Peduncle and calyx
Bacopa crenata	glabrous
Bacopa floribunda	pubescent

 

It most grows in moist amphibious conditions, though some seem to be wholly aquatic. In swamps and ditches.

Mauritius: absent.
Madagascar: Bacopa crenata grows on waterlogged, more or less flooded soils, quite fertile in sunny or lightly shaded places. It is a weed in lowland rice fields in semi-intensive culture system, in marshes and canals, humid or slightly flooded areas of low altitude on the East Coast and East of the island.
Reunion: absent.

Origin

This species is native to Africa.

World distribution

From West Africa to Angola, the Sudan and Madagascar; Kenya and Tanzania. Bacopa species are found in tropical and subtropical regions of the world, particularly the Americas.

Local weediness

Benin: Rare and not abundant.
Ghana: Rare but abondant when present.
Mauritius: absent
Madagascar:: B. crenata is a weed of lowland rice fields at low altitude, infrequent but locally abundant. It is a fast growing weed. It can be locally damaging in poorly maintained shallow rice fields, in warm wetland.
Nigeria: Rare but abondant when present.
La Reunion: absent.
Senegal: Rare but abondant when present.

Medicinal: eye treatments; generally healing; pain-killers; stomach troubles.

Global control

For global information on weed management in irrigated and low-land rice in Africa, click here.
For directions for management of annual broad-leaved weeds in irrigated and low-land rice in Africa, click here.

Local management
 
Madagascar: Only manual weeding is used to control Bacopa crenata in lowland rice fields.

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