Passioflora leaf. Light micrograph (LM) of a transverse section through the leaf (pinna) of a passiflora plant. Passiflora, known also as the passion flowers or passion vines, is a genus of about 550 species of flowering plants, the type genus of the family Passifloraceae. They are mostly tendril-bearing vines, with some being shrubs or trees. They can be woody or herbaceous. Present is a central vascular bundle made up of phloem sieve cells (blue) and xylem tracheids (red). Dicot leaves are dorsoventral as the upper and lower surfaces of the leaves are distinguished. The vascular bundle is large in dicot leaf whereas in monocot leaf, both small and large parallel vascular bundles are present. Magnification: x20 when printed at 10 centimetres wide.