Kingdom: Plantae
(Unranked): Angiosperms
(Unranked): Eudicots
(Unranked): Rosids
Order: Fabales
Family: Fabaceae
Genus: Erythrina
Species: E. crista-galli
Binomial name: Erythrina crista-galli
Common Name: Cockspur Coral Tree.
Erythrina crista-galli is a small to medium-sized exotic deciduous tree a native to Brazil, Paraguay, Uruguay, and Argentina. It is the national tree of Argentina, and its flower the national flower of Argentina and Uruguay.
The girth of its trunk can measure up to 50 cm. It normally grows to 5–8 m tall. The stem is woody with irregular, spiny branches.
The foliage is deciduous, leathery, dark green with a bluish sheen and glossy. Large compound leaves of three leaf members, oblong and lanceolate.
The root is a taproot with nodules produced by nitrogen fixing bacteria. The bacteria live in symbiosis with the tree, facilitating the tree's absorption of nitrogen in return for organic substances which the bacteria need. The tree's trunk is woody with irregular, spiny branches. These branches form a layer without definite form and die after flowering.
The tree flowers in the summer. The red flowers are arranged in inflorescences of the raceme type, is pentameric, complete, and of bilateral symmetry. Its calyx is gamosepalous, like a little red thimble. The corolla, like that of other legumes like common beans, is butterfly-shaped; however, the largest petal, called the "standard", is arranged in the lower part. The two of the petals called "wings" are so small that they are practically hidden within the calyx. The remaining two petals partially fuse together on occasion and form the flower's keel or "carina"; this protects its reproductive organs. The androecium consists of ten stamens, one free and nine united by their filaments (gynostemial androecium). The unicarpel gynoecium is welded between the stamens like a knife in its sheath.
The flowers are rich in nectar and get visited by insects, which usually have to crawl underneath the carina and thus pollinate the flowers.
The tree's fruit is monocarpic and dry, of the legume type, and no more than a few centimeters in length. The chestnut-brown seeds are cylindrical in form and are arranged sparsely throughout the seedpod's interior. The seed germ contains hypogeous cotyledons - the seeds stay underground upon germination.
The long seed pods (March)
The underside of a leaf
