These are two of the aforementioned watercolour illustrations from 'The Complete Book of House Plants" by Russel C Mott, with Illustrations by Alan Signer [Octopus Books (c) 1975]
I was particulary interested in the rendering of the tree trunks in these images; they look like stratified rock. Perhaps these bromeliads are sprouting from seeds embedded within fossils, much the same as the dinosaurs in Jurassic Park were bred from insects frozen in time within amber...
The bromeliad certainly has a prehistoric appearance about it. When I lived in Byron Bay, our house was surrounded by these plants. As well as monsteras and staghorn ferns growing vigorously upon the palm trees around the place.
Ahh, the tropics.