Gladiolus longicollis subsp. platypetalus

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

Evening fragrance suggests pollination by moths; in this case nocturnal hawkmoths. The other subspecies of G. longicollis, viz. subsp. longicollis, found in an overlapping, but more southerly distribution, is also pollinated by hawkmoths. It has a shorter flower tube, as short as 3,5 cm.

The difference between hawkmoths of the two regions? The southern one is endowed with a shorter proboscis, suitable for extracting nectar from the shorter flower tube of its region. Conversely, the northern hawkmoth 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, ensured survival of both species! Nectar presented at the base of the flower tube ensures sufficient contact between moth and flower for picking up and dropping off pollen during a series of feeding visits.

Blooming happens from spring to midsummer (Lowrey and Wright, 1987).