This genus consists of a single species - the Monvillea spegazzinii - which for some classifications could be considered a part of the Cereus family. This plant has characteristics, that allow it to be easily distinguished from the others: it consists of long thin and ribbed stems, of a typical dark color, which tend to cluster and form a very particular and unique tangle. Commonly known by the name of the "plant in the moonlight", it has in fact the particular characteristic of having large white and very fragrant nocturnal blooms. But the real peculiarity, for which it is even more appreciated, is its crested shape: together with the normal stems, its bluish crests form some sort of effects similar to a marble sculpture. It is really hard to find a cactus, that is so particular and at the same time simple to grow. With very little attention it will decorate your rooms in a truly unique way!