Gladiolus robertsoniae inflorescence

The Gladiolus robertsoniae inflorescence consists of four to eight flowers. The spike is slightly inclined and about straight. It sometimes has a smaller branch bearing fewer flowers. There are two unequal bracts below each corolla, the inner one slightly but variably smaller with notched tip.

In bud, the tepal outside surfaces may be mauve, and again when the flowers fade. The flowers are strongly carnation-scented. They remain open day and night, probably also prepared for moths, or any insect with sufficiently long proboscis, or alternatively suitable nectar gathering equipment to cope with the long tubes. 

Bloomtime is mainly in the middle of spring, rarely later to early summer.

The fruit capsules are nearly globose, the seeds ovate and broadly winged (Goldblatt and Manning, 1998; iNaturalist).