Passiflora galbana | The Italian Collection of Maurizio Vecchia

DESCRIPTION:

On warm, clear Brazilian nights white is the most visible colour, even without the moon and with only the light of the stars and the Milky Way. For this reason Passiflora galbana has chosen pure white for its flowers and to open them in the dark. Like Passiflora mucronata, to which it is closely related, it has formed an alliance with small nocturnal bats to ensure pollination and the survival of its lineage.

The structure of the androgynophore is also modified compared with that of most other species and serves this partnership with bats. In botanical terms it is said to be zygomorphic. This term is the opposite of actinomorphic. Violets and sage are examples of zygomorphic flowers, since they do not display symmetry in all directions. Roses and daisies, on the other hand, are actinomorphic, showing complete symmetry, almost as if inscribed within a circle.

In Passiflora galbana the five pollen rich anthers and the stigmas that receive the pollen to fertilise the ovary are all oriented to the same side, so as to deposit the pollen on the back of the small bats and collect it again when, wandering from flower to flower, they return in search of the nectar found at the base of the calyx, the reservoir of this sugary substance.

The large flower of Passiflora galbana has an open and slender form created by thin, long and slightly curved sepals and petals arranged in a broad, radiant star. The white is absolute and clear, without marked shading, and seems designed to capture the scant light available during the night hours.

The sepals and petals share similar shapes, elegant in their simplicity, and are arranged regularly to create a wide central space around the androgynophore. The corona, composed of several series of short, fine filaments, maintains the same pale tone as the perianth. The filaments arch slightly outward, forming a structure that recalls an inverted cone, almost suggesting the direction in which the nectar collects.

At the centre the androgynophore rises, breaking the whiteness of the corolla and corona with the anthers laden with yellow pollen. These stand out against the white of the flower and create a discreet yet clear contrast, sufficient to draw attention to the heart of the floral structure. The result is a flower that is clean and restrained, built on tapering forms and on a pure white that seems made for the tropical night in which it opens.

Passiflora galbana lives in the eastern regions of Brazil, particularly in the states of Bahia, Espírito Santo and Rio de Janeiro. It is found along the Atlantic side, within the climatic and vegetational zone of the Mata Atlântica, where it encounters the warm, humid and bright conditions typical of tropical coastal forests.

Within this same context the species develops in low elevation coastal forests and in open vegetation along the shoreline, where light and humidity alternate regularly. It may also appear farther inland in slightly drier areas, provided they are warm and well lit, using shrubs and small trees as supports. As a whole it favours bright tropical environments with well drained soils and a constant presence of heat throughout the year.

This species is very common in collections and it has always been a constant presence in mine. The generosity and beauty of its flowering, together with its ease of cultivation, make it truly valuable.

As a species originating from warm regions, it does not adapt to outdoor cultivation except in the mildest areas of our peninsula. In practice it is a passion flower for pots, in which it grows easily and rapidly. A well drained compost enriched with pumice is ideal. The pot should have a generous diameter, not less than twenty centimetres. Summer exposure should be in bright light and even in full sun, provided frequent watering is not lacking, possibly accompanied by fertiliser for flowering plants.

During winter this species requires protected environments, since it does not tolerate low temperatures and begins to suffer already at around ten degrees Celsius. A bright veranda, an unheated greenhouse or any unheated but well lit space are suitable solutions. The important thing is to avoid sudden temperature changes and cold draughts.

During this season growth slows down and watering must be much more moderate. The compost should be kept just slightly moist, without waterlogging, allowing the surface layer to dry slightly between waterings. Fertilisation should also be suspended until growth resumes in spring, when the plant begins to produce new shoots.

Overall, Passiflora galbana stands out for its combination of rare features and for the ease with which it adapts to container cultivation, proving to be a constant and reliable presence for those who love the passion flowers of tropical regions.