Cattleya walkeriana walkeriana" has been twice determined as 2"n" = 40; the diploid chromosome number of the variety "C. walkeriana" var. "princeps" has been determined as 2"n" = 80. Cattleya walkeriana Cattleya walkeriana (Walker's cattleya) is a species of orchid. It differs from most species of "Cattleya" by having inflorescences which arise from the rhizome instead of from the apex of the pseudobulb. In its native habitat (Brazilian Central Plateau) it grows as either an epiphyte or a lithophyte, sometimes in full sun. Pseudobulbs are relatively short, bulbous or fusiform, with one or two ovate leaves at the apex. Inflorescence is one-
Tilapia as exotic species Tilapia as exotic species Throughout much of the tropics, tilapiine cichlids native to Africa and the Levant have been widely introduced into a variety of aquatic systems. In the U.S. states of Florida and Texas, tilapia were originally introduced to curtail invasive plants. In an effort to meet the growing demand for tilapia, humans have farmed these fish in countries around the world. Capable of establishing themselves into new ponds and waterways, many tilapia have escaped aquaculture facilities across much of Asia, Africa, and South America. In other cases, tilapia have been established into new aquatic habitats via aquarists or