Passiflora longifilamentosa is a Brazilian species described in 2013 and belongs to the series Quadrangulares of the supersection Laurifolia, a group known for robust lianas and large fruits. It has been recorded in transitional areas of the Atlantic Forest in the states of Minas Gerais and Espírito Santo, hilly environments where forest margins, clearings and secondary vegetation alternate without sharp boundaries. The warm and humid climate that characterises these areas provides favourable conditions for the growth of many species of Passiflora, including this still little known taxon.
The sepals and petals are robust and show an inner surface of uniform dark purple, densely spotted, while the outer surface of the sepals is green. Overall, the corolla appears compact and intensely coloured.
At their base is inserted the corona, which is extremely well developed and composed of very long, slender and flexible filaments that hang downwards in a continuous manner. The filaments of the inner series are violet in the central portion and tend to become paler towards the tips, gradually narrowing and showing slightly undulating apices. Those of the innermost series are white at the base. Taken as a whole, the corona forms a pendent mass that occupies much of the central space of the flower and represents one of the most distinctive characters of Passiflora longifilamentosa, fully justifying its placement within the Series Quadrangulares.
The stem has a clearly triangular cross section, a feature that brings it close to Passiflora trialata, a related species within the same series. The petiole bears two closely spaced pairs of yellow glands, conspicuous and positioned near the leaf margin.
The leaves are entire, elliptic to obovate in shape, firm in texture and uniformly green, with a well marked central vein. The fruit is oval. The species is in fact documented only through the original publication of 2013, as it is not widespread in cultivation.
Passiflora longifilamentosa has not yet reached Europe and is absent from European collections. Knowledge of the species therefore relies exclusively on the material studied by the authors of the original description.
