[1] It covers 1,462.8 square kilometres (564.8 sq mi), from two spurs of the eastern range of the Andes to the basins of the Nangaritza, Numbala, and Loyola rivers.

Paramo or subparamo vegetation is found at elevations above 3,000 m (9,800 ft) where a complex of more than 100 lagoons exists, among the best-known being the Lagunas del Compadre.

One is in the Cajanuma Sector, about 8 kilometres (5.0 mi) south of Loja, where elfin forest and paramo habitats at elevations between some 2,900 and 3,500 metres (9,500 and 11,500 ft) can be accessed.

Its high and low mountain-forest ecosystems, located in the Nudo de Sabanilla pass, and its very humid mountain and premontane forests in the basin of the Numbala River, have more than 4,000 species of plants including trees that can measure up to 40 metres (130 ft), like the romerillo (Podocarpus glomeratus) which gives its name to the park, and many other valuable species like the Cinchona – the national tree of Ecuador – and a huge variety of orchids.

), sappanwood, arrayán, cashoco, alder, acacia, sage, guato blanco, cedar, castor oil plant, walnut, yumbingue (Terminalia guyanensis) and canelón (Swartzia littlei).

So far, 1,266 species of this family have been recorded in the northern part of the park and adjacent montane forests, a number exceeding any other place in the world.