Spermacoce ocymoides ?

Trop. Asia to SW. Pacific as per WCSP;

Argentina Northeast; Brazil West-Central; Burkina; Burundi; Cameroon; Central African Repu; Chad; Colombia; Congo; Ecuador; Ethiopia; Fiji; Gambia; Ghana; Guinea; Guinea-Bissau; Gulf of Guinea Is.; India; Ivory Coast; Jawa; Liberia; Malaya; Maldives; Mali; Myanmar; New Guinea; Nigeria; Paraguay; Peru; Philippines; Samoa; Senegal; Sierra Leone; Solomon Is.; Sri Lanka; Sudan; Tanzania; Togo; Uganda; Vanuatu; Zare as per Catalogue of life;

sperm-a-KOH-see -- seed point, referring to the capsule being surrounded by calyx points
ok-kye-MOY-deez -- resembles Ocimum (basil)

commonly known as: basil-like spermacoce, purple-leaved button weed

Native of: Mauritius, India, Sri Lanka, Indonesia, Malaysia, Philippines; naturalized elsewhere