Botanical name: Tamilnadia uliginosa
Common name: Tamilnadia
Family: Rubiaceae
Origin: SE Asia
Branches of this monotypic tree bear decussately arranged, short lateral shoots, each of which terminally produces one or two pairs of short thorns. Leaves, flowers and fruits are typically produced on very abbreviated shoots immediately below the thorns.
Link to this plant:
https://toptropicals.com/catalog/uid/tamilnadia_uliginosa.htm