Passiflora

Queensland

Extra-floral Nectaries. The leaves of Passiflora commonly bear functional nectaries on the petioles. The glands are usually disc- or cup-shaped. Some species have disc-shaped petiolar nectaries where the edges are fused to the petiole, and are more or less flush with the surface. Others possess cup-shaped nectaries that have raised edges that are not fused to the petiole. In species where petiolar nectaries occur, there are usually two (opposite or subopposite), but some species have three, and there may up to 6 in P. subpeltata. The position of these nectaries (i.e. distance along the petiole) is often diagnostic. Functional laminar nectaries are also present in many species. They occur always on the lower surface of the leaf. The glands are more or less circular and not noticeably raised above the lamina surface. They are commonly darker in colour than the rest of the lamina, and may resemble necrotic leaf tissue caused by insect damage. The number and position of laminar nectaries is diagnostic for a species. In P. aurantia, there may be up to 11 nectaries per lamina; in P. herbertiana, there are normally 2; they are absent for P. pallida.