Published by Pan Books - 1962.
Sarah Callender is a bright but naive 15 year old, who attends Bryant House Boarding School, and has just finished reading a book on the sociology of prostitution.
Having read about this her mind turns to the needs of the local boys' school. Sarah and her four friends form a syndicate to investigate the possibility of selling their services to the boys.
They convert the area beneath the school stage into their 'bordello' and advertise their wares under three categories - Vision Only; Touch and Nothing Barred.
Thus, the scene for The Passion Flower Hotel is set.
It doesn't happen without problems. Demands for certain types of girls means that Sarah and her syndicate have to expand by roping in other girls into their secret world. Eventually, things get out of hand and discovery looms.
Through it all Sarah, being the brains, manages to remain aloof which makes the others suspicious.
This is a wonderful well-written rites of passage book and the writing is witty, clever and very observant.
The look into the mind of a fifteen year old girl was so striking that many believed (and the book was marketed this way) that Rosalind Erskine was a young schoolgirl herself. That is believable for it was so modern and up to date that it did seem impossible for anyone older to have got into that sort of mindset.
Some years later it was revealed that the author was not only twice the age but, also, a man.
His name was Roger Erskine Longrigg (1929 -2000).
There were two sequals: Passion Flowers In Italy and Passion Flowers In Business - but the first book is the best in this trilogy.