Erythrina caffra, the South African coral tree

Its flower fill of color the forests of South Africa

The South African coral tree is a leguminous tree with scientific name Erythrina caffra. Its spectacular bloom and adaptability to subtropical and Mediterranean climates, frost-free around the world have become one of the most beautiful plants of the flora of South Africa. In its native coastal forest grows to a height of approximately 200 meters over level sea.

Erythrina caffra flowers of an intense and bright orange-red. Its successfull scientific name defines it to perfection: Erythrina from the greek erythros meaning red and caffra which is the Latin name of the Kaffirs region of Africa where it is native, ie South Africa.

South Africa's beautiful coral tree in full bloom in early May photographed in the Elche city of Alicante province (Spain). The flowers open before the leaves, which further enhances the beauty of flowering. This tree can reach 12 feet in cultivation and up to 20 meters in its natural habitat. The most spectacular examples are found in the Alexandria Forest that is part of the Addo Elephant National Park in the Cape Region. Its branches are protected by spines short and thick. The leaves are trifoliate and have no spines on the rachis and petiole. The wood is brittle and lightweight, so should plant it in a place sheltered from strong winds.

Erythrina caffra spectacular inflorescences that seem to fire flares. The flowers produce no perfume. Pollinators, mainly birds, are attracted by the striking red color of the petals and the nectar reward of nourishing the flowers produced in abundance. Each flower contains up to 10 drops of nectar (about 1 cc.) And each cluster consists of about 80 flowers, which secrete therefore about 800 drops of nectar (about 80 cc.). Considering that in the crown of a mature tree can have up to 2000 inflorescences, ie up to 160,000 flowers, the total calculation gives us a production of 1,600,000 = 160,000 cc drops. = 160 gallons of nectar per tree. The Erythrina caffra effort to ensure the next generation is truly titanic.

It has been demonstrated pollination of the flowers of this legume species by the starlings Onychocnathus morio, the nightingales of the genus Pycnonotus sp., the yellow weavers of Ploceus subaureus species, the sunbirds of genus Nectarinia sp., the birds of the genus Orioles sp., and many other birds in the middle of spring can be seen in flocks of hundreds of individuals visiting the trees in bloom.

Erythrina caffra immature legumes photographed at the Lisbon Botanical Garden in early May.

South African mature legumes of coral tree in early May. The seeds remain attached to the opened shells, which are shifted away from his mother by gusts of wind and torrential rains, thus facilitating the conquest of new territories. As with many seeds without juicy pulp around, the ones of Erythrina caffra present two limitations to germination, so-called external lethargy and internal lethargy.

Erythrina caffra seeds of a deep red. The brighter cuticle that cover it is waterproof. Represents the so-called external lethargy. For the embryo to hydrate and leave the internal lethargy should be scarified by bacteria, fungi and soil acids, which erode the cuticle and make it permeable to water ingress. Once they have been scarified, seeds need two more requirements for its embryo leaves the internal lethargy: moisture and direct sunlight. Seeds that remain under the crown of its mother or have the misfortune to be moved to a shady spot, although the cuticle was permeabilized to hydration, do not germinate because they need sunlight to impinge on them or on the thin of land that covers the embryo to awaken the inner lethargy.

Small South African coral tree sprouted recently. In one of the two cotyledons can be seen the mechanical loosening which underwent the seed scraping against a sandstone block to break the cuticle and facilitate hydration of the embryo. Once scarified I planted in a pot I placed in full sun. The light sensors detect seed sunlight having an impact on the thin layer of soil that covered it and woke the embryo.

 Trunk of an old copy of Erythrina caffra from Lisbon Botanical Garden.

Rough and gray bark of previous trunk traveled by longitudinal white lines.

Pericartiellus durieui, an Umbilicus rupestris parasite.

Its larva secretes hormones that cause abnormal plant growths called galls.

The beetle Pericartiellus durieui (Lucas, 1846) depends on both the crassulaceae Umbilicus rupestris for playback that if this persists, it would too.

Galls caused by Pericartiellus durieui larvae in the stems of Umbilicus rupestris. (I recommend enlarge photos with a double click).

Its scientific name, as with many animal and plant species, is not without controversy among entomologists. Many of them give it other names: Nanophyes durieui and Nanophyes Lucasi, but it seems that the name internationally accepted as valid is to Pericartiellus durieui. See European Environment Agency.

Several copies of Umbilicus rupestris galls. All images were taken guts in early May in a dry stone wall of the Parc Natural del Carrascar de la Font Roja in Alcoy, Alicante. The exuberance and diversity of the flora of this park is spectacular.

The female beetle, once it has been fertilized by a male, looking Umbilicus rupestris plants healthy and lays its eggs inside the fleshy stems, just below the plant cuticle. Following commissioning in late summer, the adults die. Thus ends the life cycle and start a new one.

Previous galls with details of the inflorescence of Umbilicus rupestris who barely been able to develop, as the parasite larvae secrete hormones that inhibit flowering, to ensure their galls the contribution of substantially all of the water and nutrients up from the roots of the host.

Two plants of Umbilicus rupestris with galls.

Previous galls with details of the inflorescence inhibited by hormones of the parasite.


In this image of Umbilicus rupestris healthy with long inflorescences and stems without galls very well appreciate the differences between parasitized plants. 

Several galls halved to view its contents.

In early fall the eggs hatch inside the stems of Umbilicus rupestris and the larvae begin to secrete hormones that cause an exaggerated and abnormal growth of plant tissues that surround it, as if they were true cancerous tumors called galls. This tumor tissue serves as food for the larvae and also protects it from predation by insectivorous birds and it can withstand the cold long winter.

In the right half of this gall is the head of a larva of Pericartiellus durieui and half left transparent larva after another tumor tissues.

The larvae grow in the fall, winter and spring fed by the moist tissues of the barb, digging in her galleries as they feed. In early summer the larva undergoes a metamorphosis and becomes a nymph.

 Above larva with an arrow.

In the upper right half of this gall can see a small white larva.

Previous larva about 3 millimeters long and 1 mm thick with brown head and white body.

During the first weeks of summer, the pupa is gradually metamorphosing their internal organs and in September becomes an adult beetle, a tiny coleopter a few millimeters, which opens an outlet in the gall cuticle and emerge outside. Then the female emits sexual pheromones to attract males flying towards her, copulate and fertilize their eggs. After copulation the males die and the mated female flies in search of healthy Umbilicus rupestris to lay their eggs, after which she dies. And again begins the peculiar life cycle.

Pericartiellus durieui adult insect. This image is owned by the magnificent website:

The Gibraltar Ornithological and Natural History Society