Doctor Dolittle in the Moon by Hugh Lofting

Another peculiar thing that baffled us completely, when we first came into the marshy regions of the Vanity Lily's home, was the variety of scents which assailed our noses. For a mile or so around the locality there was no other flower visible; the whole of the marsh seemed to have been taken up by the lilies and nothing else intruded on their domain. Yet at least half a dozen perfumes were distinct and clear. At first we thought that perhaps the wind might be bringing us scents from other plants either in the jungle or the flowering heath lands. But the direction of the breeze was such that it could only come over the sandy desert areas and was not likely to bring perfumes as strong as this.

It was the Doctor who first hit upon the idea that possibly the lily could give off more than one scent at will. He set to work to find out right away. And it took no more than a couple of minutes to convince him that it could. He said he was sorry he had not got Jip with him. Jip's expert sense of smell would have been very useful here. But for ordinary purposes it required nothing more delicate than an average human's nose to tell that this flower, when John Dolittle had communicated the idea to it, was clearly able to give out at least half a dozen different smells as it wished.