Ziziphus spina-christi, the Christ's Thorn Jujube is an evergreen tree native to northern and tropical Africa and southern and Western Asia.

Serving as a claim in establishing its provenance, it has been suggested that this spiny plant was used for the "crown of thorns" worn by Jesus, though others have suggested Christ's thorn jujube (Ziziphus spina-christi).

Flora includes Tamarix, Willow, Ziziphus spina-christi, Pistacia atlantica, Faidherbia albida, and Prunus korshinskyi trees.

One significant name is Dadiangas (Ziziphus spina-christi), their native call for a tree which has thorns on its trunk and stems that abundantly thrive in GenSan during the time.

The coastal mangrove consists of Avicennia marina, trees of the inland savanna include Ziziphus spina-christi, Prosopis cineraria and the Umbrella Thorn Acacia tortilis while the mountains are home to Ficus cordata salicifolia, and Acacia tortilis.