|250-500 cm (8.2-16.4 ft)
|mid summer to early autumn
|climber, edible fruits rhizome
|USDA Zone 7-9
Passiflora incarnata L., sometimes known as Maypop, is native to south-eastern USA, reaching the coldest area of its natural distribution in Illinois, Indiana and Ohio, but has also been introduced to regions of India. It prefers sunny, dry locations, but is rather tolerant for soil conditions. The dark leaved vines can quickly cover 3-5 meters of trellis, climbing with long tendrils which coil up to pull the vine higher. When well established, it may produce expeditious suckers, sending up vines in several meters distance from the main plant and can be troublesome under good conditions. Due to the extensive underground spread, Maypop is never really happy in pots, though it will flower. The biggest threat to them are slugs, especially during the late emergence around May. The plants are the exclusive host plant for gulf fritillary butterflies. Reproduction may be carried out by cuttings, by isolating the adventurous roots or trough seed, though those germinate rather erratically.
Maypop is a highly useful plant, carrying edible fruit if the self-incompatible flowers are pollinated by a different individual or another member of subgenus Passiflora. Commercially available plants in Europe are often clones of a single plant, so either combine the normal form with the white flowered 'alba' or grow at least one plant from seed. Leaf extracts are used in mild sedatives and anxiolytics. While being very common in Europe (where the advertisements often wrongly feature the more commonly known Passiflora caerulea), the usage in the USA mostly stopped 1978, when new regulations for medical safety and effectiveness were introduced.
The white and purplish flowers with the wavy corona are somewhat variable even on the same plant. Martin Bohnet speculates the flower color to be dependent on night temperatures, getting darker with colder nights. While a single flower lasts about 2 days, the flowering period goes on for months from late June to mid September. Pollinators are mostly bees and bumblebees, while wasps tend to give more attention to extrafloral nectaries at the leaf axles. Fruits reach the size of a hen egg, start out green but get yellowish as they ripe.