Oliver D, Hooker JD (1885) List of the Plants collected by Mr. Thomson, F.R.G.S., on the Mountains of Eastern Equatorial Africa, with Observations on their Distribution. Journal of the Linnean Society of London, Botany 21(136): 392-406. doi: 10.1111/j.1095-8339.1885.tb00570.x.
There is no corrections for Gladiolus watsonioides yet.