Subtropical Paraná forest ( Selva Paranaense ) is Argentina's most biologically diverse ecosystem, a dense mass of vegetation that conforms with most people's idea of a jungle. The most frequently visited area of Paraná forest is the Parque Nacional Iguazú, but it is found in patches across lowland areas and upland hill ranges of the rest of Misiones, with small remnant areas in the northeast of Corrientes Province. It has over 200 tree species, amongst which figure the palo rosa (one of the highest canopy species, at up to 40m); the strangler fig ( higuerón bravo ); the lapacho , with its beautiful pink flowers that have made it a popular ornamental tree in cities; and the Misiones cedar ( cedro misionero ), a fine hardwood species that has suffered heavily from logging. Upland areas along the Brazilian border still preserve stands of Paraná pine , a type of rare araucaria monkey puzzle related to the more famous species found in northern Patagonia. Lower storeys of vegetation include the wild yerba mate tree, first cultivated in plantations by the Jesuits in the seventeenth century; the palmito palm, whose edible core is exploited as palm heart; and endangered prehistoric tree ferns . Festooning the forest are llianas, mosses, ferns and epiphytes, including several hundred varieties of orchid .