Boerhavia repens L.

 Global description
Boerhavia repens is a prostrate plant characterized by its cotyledons and its opposite lanceolate leaves, which are of different size. The flowers are assembled in small axillary cymes. They measure less than one millimeter in diameter. They are formed by a calyx with ribbed tubular base, enclosing the ovary with a top colored petaloid. The corolla is absent. The capsule is indehiscent, strongly ribbed and has a short pubescence.

Cotyledons
The cotyledons have a  finely pubescent, oval orbicularis leaf blade. They are of unequal size; one measuring 4 mm in diameter, while the other measuring 5 mm in diameter.
 
First leaves
The first leaves are simple and opposite. They are distinctly stalked. The lamina is oval. For each pair of sheets, one of them is more developed than the other. From one internode to the other, the position of the large leaf changes.
 
General habit
The growth habit is fully prostrate. The plant is very branched as from the base, but is not really covering.
 
Underground system
The plant has a taproot system.
 
Stem
The stem is hollow and cylindrical. It is thin and dotted with small and very short hairs.
 
Leaf
The leaves are simple and opposite. Each pair of leaf has a large leaf opposed to a smaller leaf. The position of the large leaf varies in each pair.
They are held by a narrow petiole of 5 to 10 mm long. The lamina is oval lanceolate, 15 to 25 mm long and  5 to 10 mm wide. The base is wider, and the top is acute or acuminate. The margin is entire. Both sides are practically glabrous,and  green-brown in colour. The lower face is brighter than the upper face.
 
Inflorescence
The flowers are  arranged in very axillary cyme held by a stalk of 10 to 20 mm long. Each cyme contains 2-5 flowers.
 
Flower
The flowers are small, measuring less than 1 mm in diameter and 3 mm long. At the base of the flower, are two long linear leafy bracts 1 mm long, with an acute apex. The calyx is tubular and consists of 2 parts. The lower part is a ribbed tube covered with short hairs and enclosing the ovary. The upper part is a tube ending in 5 petal like rounded lobes. This part is pale pink. The corolla is absent. The stamens are of from 3 to 5, fixed to the base of the petaloid part of the calyx. The ovary has only one loculus. The style reaches the top of petaloid calyx.
 
Fruit
The fruits are indehiscent capsules 4 mm long and 1 mm wide, formed by the lower part of the calyx which is closed at the top when the upper part, petaloid, falls off after fertilization. They are obovoid including 3-5 longitudinal ridges covered by a short pubescence. They contain a single seed.
 
Seed
The seed is ellipsoidal, 2 mm long and 1 mm wide. It presents a wide ventral furrow.

 World distribution

B. repens is common in the tropics.

https://www.gbif.org/species/3086288