Vinca minor (lder) is a deciduous tree that grows primarily in the rainforests of Brazil and Peru. It is known as the vinca or “wing nut” tree. Vinca minor has a wide distribution in the Amazon, with some species occurring as far north as the Venezuelan Andes and as far south as Patagonia. The tree prefers full sunlight, sandy soil, low fertility, high humidity, and well drained conditions. Its leaf shape is that of a gooseberry.
The trunk of this deciduous tree is robust with a tapering trunk and leaflets that have four to nine white pointed branches. The tree’s leaves grow in groups which are black, leathery and broadly toothed. The tree’s flowers are blue, pink or even yellow and fall in two distinctly distinct forms: a inflamed and heavily blushed catalepena or azalea flower, and a single ovary form at the base of the flower. The flowers are highly volatile and can be quite toxic when they turn black.
The tree’s bark is black and thick; it is glossy and somewhat fibrous. Bark contains alkaloids and terpenoids which stimulate mucous secretion and increase blood flow to the extremities. The resin from the tree’s bark contains an alkaloid called cineole which is active during cold weather when the leaves drop off.
The white spined frond is a trapdoor into the bark. The trapdoor is open so that the sapwood inside can drain into the root system and the inner bark can dry. The white spined frond can be easily pulled from the tree. However, the trapdoor is closed and will not allow any drainage unless there is direct contact with another leaf or stem. The end result is a dried out frond full of dead plant material and a useless structure.
The most toxic part of the vinca tree is its needles. Vinca seeds, which contain resin, are in the needle’s center. When the needle is pruned, the resin dries quickly. Pruning must be done immediately after blooming or the resin will be present when the flowers appear. If left unattended, the dried out needle shape will begin to attract vermin and other insects which will cause severe damage to the plant.
The needle’s base is covered with small, whitish hairs and needle shaped scales. The scales look like coarse sandpaper and may be seen easily in the eye. These scales on the trunk and branches of the vinca tree serve as protection from predators. They are also used to trap insects and other small creatures which might otherwise try to climb the tree and reach the sap or pollen sacs. Unfortunately, the vinca bark glands are the bane of this tree’s existence since they continually release bark and pollen.
The vinca bark is not only unsightly, it is also irritating to humans. Each vinca leaf has up to eight needle-shaped scales along its length; each scale is marked by a small number. All vinca bark contains small numbers of stellate fungi. These fungi secrete a liquid which attracts ants and enables them to climb and latch onto the leaves of the vinca tree where they remain for an extended period of time, until the homeowner or gardener notices that the needles within the bark are falling off.
To get rid of Vinca, the gardener must first identify and remove the plant. The most effective way to do this is to trim the roots of the plant until there is nothing on the stem to grab hold of. This will prevent the vinca from climbing up the tree and continue to produce its resin. Once the vinca has been removed, the gardener should wash any clothes he may have worn around the affected area, as traces of the resin may be difficult to remove. If the vinca has already grown, and is producing its resin, a weak insecticide may be used to repel the insects.
