You frequently hear that new hobbyists are intimidated by Selaginella species. Mostly because they have a tendency to melt, sometimes what seems overnight. I think there are multiple reasons for this. In my experience there are two main ones. First, most of the commercially available species are grown in greenhouses and at lower humidities and moisture levels then what you regularly find in a terrarium. When put into your terrarium the sudden changes causes them to melt. With careful acclimation this can be avoided to some degree. Once established these species usually do very well. But, that leads me to my second reason, the species themselves. I am convinced that many times old world species, which most of the commercially available species are, just tend to melt easier. New world species coming from Central and South America, generally seem to be more adaptable to sudden changes in their culture (of course to a degree). This is just anecdotal observations after years of working with this genus. You just do not see the same tendency to melt when thrown into a terrarium. And given reasonable care, they start to flourish very quickly. While there certainly are old world ones that are also very adaptable, it is hard to go wrong with species from the Neotropics. With an influx of new ones coming into the hobby, now is the time to get over any fears and give Selaginellas another try. The range in habit and appearance is remarkable, and so many of them add a look to a terrarium that no other plant can.