Passiflora vitifolia

P. vitifolia is a common forest species of Passiflora, often growing in the canopy. However, the bright scarlet flowers bloom in the forest understory and new growth shoots are often to be found at ground level near the flowers, in treefall clearings or forest edge. Interestingly, this species is also common across the artificially maintained successional plots (cut every five years on a rotating schedule), where other forest species P. ambigua, P. pittieri and P. lobata do not thrive. Range: from Nicaragua to Bolivia, Venezuela and Western Brazil; in wet primary or secondary forest and forest edges 0-1500 meters elevation.

Like P. oerstedii and P. lobata, P. vitifolia leaves do not produce cyanide when crushed. However, the stems are mildly cyanogenic, producing 0.1 to 0.5 μM HCN/g plant tissue, and the green fruits should be considered toxic (up to 2.2 μM/g in the rind). P. vitifolia rootlets are also mildly cyanogenic, releasing .025-.1 μM/g HCN. Smiley and Wisdom (1985) found full-sized leaves this species to contain 7-15% dry weight of tannins, chemicals which may interfere with the enzymatic release of HCN.

P. vitifolia is the most commonly used host plant for both Heliconius cydno and H. hecale at La Selva, both species laying their eggs on the tips of the new, uncoiled tendrils. H. melpomene is also quite capable of feeding and growing on P. vitifolia, even though it is not found on that species in nature. The large ear-like petiolar nectaries are very attractive to ants such as Ectatomma, and plants which are regularly tended by these ants seem to be quite well-protected against Heliconius caterpillars (Smiley 1986).

P. vitifolia is also fed upon by flea beetles, including the Passiflora-generalist Blue Flea Beetle (Monomacra violacea), the Black-tibia Flea Beetle (Parchicola "black tibia") the and the Yellow Ptocadica Flea Beetle (Ptocadica "yellow"). The Yellow-tibia Flea Beetle (Parchicola "yellow-tibia") and the Yellow-legged flea beetle (Parchicola DF2) have also been found on this species.

 
P. vitifolia fruits are distinctive-looking.
 The flowers are spectacular, pollinated by hummingbirds.
The thin grape-like leaves give the plant its name.
  
The huge nectaries are very attractive to ants, which protect the plant against caterpillar attack. The fruits are tasty when ripe, but the green fruits are toxic, producing cyanide gas when mashed.
Tendril with young caterpillar. Drooping new growth shoot, irresistable to ovipositing female Heliconius cydno
Ectatomma tuberculatum at nectary Another flower picture.
An H. hecale or H. cydno egg on P. vitifolia tendril. These can't be distinguished from each other until about the third instar, when the spots on the cydno become evident. H. hecale larva don't have spots. A Black-tibia flea beetle Parchicola "black-tibia" feeding on P. vitifolia. This seems to be the most common species of Parchicola feeding on P. vitifolia, but this needs to be verified with additional positive identifications.