Increased yield from transgressive segregates of a Stylosanthes capitata cross in a tropical oxisol.

The word "oxisol" comes from '"oxide"' in reference to the dominance of oxide minerals such as bauxite.

This plant grows on and is named for the Ione Formation, a local geologic formation of the iron-rich oxisol soil type.

G. deplancheanum occurs on ferralitic ferritic desaturated hardpan or gravelly soils (oxisol) on the southern massif at altitudes between 200 and 1,000 m".

They are extremely highly weathered tropical soils, with high levels of iron and aluminium oxides (oxisol) and mercury, and they contain high levels of natural radioactivity.