Greenhouse

Jose is a a boarding school student. His father gets remarried and Lange, a pretty blond boy, becomes his stepbrother.
They stay in a countryside house during summer while their parents are in their honeymoon trip.
A strange green house full of withered rose plants lies near the river.
Jose falls in love with Lange, but there is a spirit in the greenhouse who wants Lange all for himself...

Published in the 1975 anthology Alois.