Passiflora watsoniana | The Italian Collection of Maurizio Vecchia

DESCRIPTION:

Passiflora watsoniana is native to eastern Brazil, where it grows naturally along forest margins and in areas of secondary vegetation within the Atlantic Forest biome. It favours warm and humid zones with rainy summers and mild winters, but it can also adapt to less stable conditions provided they are not too dry.

It was one of the first passionflowers in my collection, and my earliest photographs of it date back to 2004. I remember being struck by the flower’s airy corona, a delicate mass of filaments arranged like a soft plume. The outer filaments, long and close to the corolla, follow one another in a continuous sequence with others that are gradually shorter and finer, ending against the androgynophore.

The flowers of Passiflora watsoniana are among the most elegant in the Kermesinae group. Unlike most species of this section, it does not display the typical red or deep pink colouration but instead shows shades of violet. The structure is slender, with a wide corolla formed by reflexed sepals and petals of white, sometimes slightly greenish near the base. The corona, composed of a great number of filaments, opens in a light and orderly display. The outer filaments are long and thin, of deep violet with alternating white and purple bands, while the inner ones, progressively shorter, take on brownish-violet tones and end in small white tips. The overall effect is one of great harmony, with a continuous gradation of colour that draws the eye towards the centre of the flower.

The flower is not large, with a diameter of about seven to eight centimetres, but it is a generous and reliable bloomer. The plant has a light habit, with slender and flexible stems that branch easily, and small leaves that are often trilobed. The underside of the leaf blade is tinted with reddish-purple, a tone that stands out when light filters through the vegetation.

Passiflora watsoniana is easy to grow in a pot, and in regions with cold winters (USDA zones below 9A) it is advisable to keep it in a greenhouse or bright veranda, maintaining the temperature around 10 °C. During the growing season it develops rapidly but never becomes invasive, forming an elegant tangle of thin stems.

The ideal soil is well drained, not heavy, and lightened with materials such as pumice or perlite. It appreciates constant humidity but not waterlogging, and during the summer it responds well to regular feeding with fertilisers richer in potassium than in nitrogen and phosphorus, which encourage continuous flowering.

Propagation by cuttings is straightforward and produces vigorous young plants that can flower as early as the second growing season. Under optimal conditions Passiflora watsoniana may flower for many consecutive months, offering a succession of graceful and delicate blooms. Although it is not among the most striking species, it possesses a quiet charm that makes it unmistakable among the Kermesinae group of passionflowers.