Spermacoce verticillata L.

Global description
 
Spermacoce verticillata is an erect or semi prostrate plant, with lignified base, 30 to 80 cm high. The stems are quadrangular, highly branched and shortly hairy. The leaves are opposite or in false whorls, sessile or subsessile with elliptical blade and scabrous margin. The flowers are white or pale yellow, sometimes tinged with red, 2 to 3 mm long, assembled in globular glomerules 1 to 1.5 cm in diameter. The fruits are small oval or oblong capsules.
 
Cotyledons

Cotyledons subsessile, oblong elliptical blade, semi fleshy.
 
First leaves

First leaves simple, opposite, decussate, sessile, elliptical to lanceolate blade. The margin is entire, slightly scabrous, the depressed central vein is visible on the upper side. The faces are glabrous.
 
General habit

Bushy perennial herb, extensively branched from the base, erect, 30 to 80 cm high, lignified at the base.
 
Underground system

Big taproot.
 
Stem

Quadrangular stem, solid, abundantly branched from the base, erect or semi prostrate, covered with short, abundant hairs.
 
Leaf

Leaves simple, opposite, decussate, but appearing whorled by the presence of undeveloped axillary shoots leaves. The leaves are sessile to sub sessile. At the base is a stipular collar joining the two opposite leaves, 2 mm long, with bristles of 1.5 mm long. The lamina is linear lanceolate, 10 to 45 mm long and 1.5 to 5 mm wide, acute to acuminate at the apex, narrowed in corner at the base or attenuated into false petiole. The margin is entire and scabrous. The surfaces are glabrous except the very prominent scabrous midrib on the underside.
 
Inflorescence

Inflorescences in spherical axillary glomeruli,  0.7 to 1.4 cm in diameter, with apical and subapical nodes, subtended by short leaves reflected downwardly, comprising of a large number of small tuberculate flowers.
 
Flower

The flower has a subcylindrical calyx, 1.25 mm long, topped with 2 lobes more or less ended in a point. White or pale yellow corolla, sometimes tinged with red, in long tube of 2 to 3 mm, ending with 4 small reflected lobes.
 
Fruit

The fruit is a glabrous capsule with 2 loculus, oblong, topped by the calyx lobes and carrying a dorsal appendage 1.7 to 2.4 mm long and 1.2 to 1.4 mm wide.
 
Seed

Narrowly oblong ellipsoid seed, 1.2 to 1.6 mm long and 0.3 to 0.6 mm wide, finely reticulated, blackish brown in colour.

Origin

Spermacoce verticillata is native to the Americas from the USA to the southern part of South America.

Worldwide distribution

The species was introduced in Africa and Madagascar but absent from other islands of the Indian Ocean. It is also present in India in the state of Kerala and Austalia (North and East)

https://www.gbif.org/fr/species/2918574