Hibiscus insularis

Hibiscus insularis

Hibiscus insularis is a rare plant of the Mallow family. It is endemic to the Phillip Island.

Features

Hibiscus insularis is a densely branched shrub that reaches a height of 1 to 2.5 meters. The crown is rounded. The egg-shaped, notched leaves are 4-6 inches long. The flowers appear singly in the leaf axils. You can reach a diameter of 8 centimeters. Each flower has three to six egg-shaped 10 to 13 mm long bracts, a bell-shaped five-lobed, tomentose about 22 millimeters long calyx and five elongated bright lemon-yellow partially bent about 6 inches long petals. The flowers are pink and leaf veins with age get the whole flower a pink coloration. The fruit is composed of five compartments which are surrounded by a permanent cup.

Ecology

The seedlings of Hibiscus insularis have very small leaves which are formed in a deeply lobed juvenile form. This stage can be maintained up to 20 years before the adult form of the leaves is produced. Since only leaves so far been discovered in the adult form, it can be considered from a long generation time for Hibiscus insularis. The flowers of Hibiscus insularis grow upward at the ends of branches with rarely more than a flower in the same phase on the same branch. It produces large quantities of nectar. When the flowers open the first time, they are female, a day later they have reached the male stage. During the next days the flowers get a pink coloring and close when they wilt. It is believed that Hibiscus insularis is pollinated by birds, but it is possible that the original pollinators are extinct. Hibiscus insularis is capable of producing seeds by self-pollination. Also vegetative propagation by stem cuttings is possible.

Inventory and risk

In the past, overgrazing and land degradation by feral pigs presented, goats and rabbits a high threat it proceeded from renaturation and protection projects, the imported animals were removed from the Phillip Island. Today, the greatest threat of neophytes such as the olive tree Olea europaea subsp goes. africana from. The African olive tree competes with Hibiscus insularis for water and nutrients. It forms dense thickets that block the propagation of Hibiscus insularis. Moth caterpillars, especially those species and Pectinophora andScutigera Anisoplaca Cosmia, reduce the ability of these hibiscus way to produce viable seeds. Soil erosion on the Phillip Island also complicates recovery of native vegetation. 1939, only 13 individuals were counted. In 1963 the population consisted of eight plants. 1988, the species was observed in two small towns, each having an area of ​​500 m². In 2001, a third place added with an area of ​​500 m². 2003, the number of species in the wild adult plants less than 50 In cultivation, the species grows among others in the Norfolk Iceland Botanic Gardens, in the Booderee Botanic Gardens at Booderee National Park and the Royal Botanic Gardens Melbourne.