Vachellia collinsii
Ball head (Acacia collinsii )
The ball- acacia ( Vachellia collinsii ) is a species of the genus ( Vachellia ) within the legume family ( Fabaceae ). She comes from the dry forests of southern Central America and one of the ways of the tribe Acacieae in the hollow thorns different species of ants, for example Pseudomyrmex spinicola and Pseudomyrmex ferruginea live ( Myrmekophylaxis ).
Description
The ball- acacia grows as a small tree, reaching heights of growth of up to 10 meters. The dark gray to brown bark is slightly furrowed. The bark of the branches is smooth and reddish- brown to dark brown. The alternate arranged on the branches leaves are divided into petiole and leaf blade and 4 to 16 inches long. The 4 to 18 millimeters long petioles have their base from two to five, broad dome-shaped glands. The bipinnate leaf blade consists of 3-15 pairs of pinnae first order. Each pinna first order contains 11 to 29 pairs of leaflets. The side leaf spines are light reddish brown to dark brown and round in cross section.
The flowering period extends from January to August. The flowers are in cylindrical aged men inflorescences, which are surrounded by four bracts. The flowers are yellowish seated with five 1 to 1.4 mm long sepals and five petals only slightly longer. The dark brown to black legume is 3 to 6 inches long and straight. The seeds are dark brown, egg-shaped and bear a yellowish aril.
Symbiosis
The stipule thorns of the acacia - ball head are hollow and serve the ants, which only have to expose an access just below the top, as a residential city. The aggressive ants protect the tree from feeding damage by insects by selling all insects that settle on it. They also keep the surrounding acacia, competing vegetation short. In exchange, the tree produced by the glands on the petioles nectar and at the ends of the leaflets protein - and fat-rich food body ( Beltsche body ) to feed the ants.
An ant colony can populate several acacias. Acacia, still harboring no ant colony must produce stomach poisons to ward off herbivorous insects. Young acacia plants without ant colony grow more slowly and are quickly overgrown by other plants.
Dissemination
The ball head has acacia of all " ant acacia " next Vachellia cornigera the widest distribution and is most adaptable. Vachellia collinsii comes in Mexico in Yucatán and in the central Chiapas in Guatemala in the northern province of Peten, in the eastern half of Honduras and its short coastline on the Pacific Ocean, in Nicaragua, in northwestern Costa Rica, in the province of Guanacaste on the Nicoya Peninsula and on the Pacific side of western Panama Azuero Peninsula to the front.
Taxonomy
The first description was under the name ( basionym ) Acacia collinsii Saff. The new combination to Vachellia collinsii ( Safford ) Seigler & Ebinger in 2005 by David S. Seigler and John E. Ebinger in New Combinations in the genus Vachellia ( Fabaceae: Mimosoideae ) from the New World published in Phytologia, Volume 87, p 150. Other synonyms are Myrmecodendron collinsii ( Saff. ) Britton & Rose, Acacia nelsonii Saff. , Acacia penonomensis Saff. , Acacia gluteal Ram. , Acacia costaricensis Schenck, Schenck panamensis Acacia, Acacia yucatanensis Schenck.
Swell
- DH Janzen: Swollen - Thorn Acacias of Central America. In: Smithsonian Contributions to Botany. 13, 1974 ( PDF).
- Vachellia collinsii at J. Miller: Acacia Systematics and Ecological Genomics.