Colletotrichum siamense H. Prihastuti, L. Cai & K.D. Hyde, was described as a species associated with coffee berries by Prihastuti et al. (2009). Based on the analysis of the ApMat marker, C. siamense species is part of the C. siamense complex along with six other species, C. dianesei, C. endomangiferae, C. hymenocallidis, C. jasmini-sambac, C. communis and C. murrayae (Sharma et al., 2014).

Colletotrichum siamense is part of the C. siamense complex. Due to its wide distribution and its interaction as a phytopathogen in commercial crops, I suggest its inclusion in Least Concern.

The species in known in 12 countries. In Brazil, it is known in 2 of the 26 states.

There are about 60 records of this species in GBIF, being 2 of them in Brazil.

The species is predominant in number of records in Mexico. In Brazil, the specie is found in the Atlantic Forest and Pampa.

In Brazil, this species occurs in the Pampa biome and in the Atlantic Forest, the latter being a global biodiversity hotspot.

Half of the records in Brazil are in unprotected areas.

Studies in different areas may reveal important data about the ecology of this species.

Unknown.