Identification 17 Botany 15 Orchids 12 Birds 9 Pictorial works 8 Ecology 7 Plants 7 Natural history 6 Varieties 6 History 4 Insects 4 Mammals 4 Orangutan 4 Rain forest ecology 4 Rain forests 4 Research 4 Trees 4 Wildlife conservation 4 Habitat 3 Pitcher plants 3 Zoology 3 Animals 2 Beetles 2 Behaviour 2 Biology 2 Biotic communities 2 Butterflies 2 Centennial celebration, etc 2 Classification 2 Congresses 2