Gladiolus floribundus is a geophyte, which produces corms enclosed within firm tunic layers. The stem is erect and the whole plant grows 150 to 450 mm tall. Its leaves are sword-shaped and about 12 to 20 mm in width. This species produces unscented, funnel-shaped flowers which can be white or light pink, with darker median striped patterning. As the species name suggests, it is free-flowering and the spike can be adorned with up to 10 flowers or more in some instances. Flowering occurs in spring, between late September and November. Bracts are a combination of greyish purple and dull green and 40 to 50 mm long.

Gladiolus floribundus is closely related to G. miniatus, G. grandiflorus and G. rudis and are thought to share a common ancestor because of vegetative similarities, such as being shorter plants and having firm and fibrous tunics surrounding the corms. They differ however, in the appearance of their flowers which show that the four species have adapted to different pollinators. Their habitat ranges also differ for the most part, from clay soils for G. grandiflorus to limestone outcrops where one can find G. miniatus growing.