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.