Gladiolus longicollis subsp. platypetalus tube and bracts

Gladiolus longicollis subsp. platypetalus produces only one or two flowers per stem. The flowers are white or cream coloured. This subspecies is noted for a very long, thin flower tube, sometimes over 12 cm in length.

Sweet evening fragrance suggests pollination by moths; in this case nocturnal hawkmoths. The difference between hawkmoths of the two regions where the flowers only partly overlap? The southerly hawkmoths are endowed with shorter proboscides, suitable for extracting nectar from the shorter flower tubes of G. longicollis of their region. Conversely, the northern hawkmoth active on these flowers has a long proboscis to access nectar from the flowers more prevalent in its domain. A slow process of shared speciation, co-evolution between plant and insect, morphing in tandem, ensuring survival of both species. Nectar presented at the base of the flower tube ensures sufficient contact between pollinator and flower for picking up and dropping off pollen during a series of feeding visits.

Apart from only partly overlapping geographical distributions, the two subspecies don't flower totally in the same season, reducing cross-pollination that would succeed but remove or reduce the subspecific differences. Subsp. longicollis blooms in spring, subsp. platypetalus from spring to early summer, sometimes to nearly the end of summer (Goldblatt and Manning, 1998; Pooley, 1998; Lowrey and Wright, 1987; iNaturalist).