Pasture problems: indigenous plants in relation to habitat and sown species

(1) Grassland has been classified as natural and semi-natural; both classes have been further sub-divided according to the botanical composition of the herbage in relation to habitat (pp. 27–36). (2) The plants which colonise natural grasslands have been called primary indigenous species; and those which come in without being sown and contribute largely to the herbage on semi-natural types have been designated secondary indigenous species (p. 37).