Hsu, H.W.C., Aranas, D.R., Alejandro, G.J.D. & Liede-Schumann, S. (2020)

A new species of Argostemma (Rubiaceae) with free stamens in star-shaped corolla from the Philippines

. Phytotaxa 437 (2): 113–117. https://doi.org/10.11646/phytotaxa.437.2.7