Flowering Cacti or Desert Gems – If you’re looking for a burst of color in your workplace, these cacti are the answer and they will reshape your office view. They help purify the air and the best part is that they come in different colors: yellow, orange, pink and emerald green. They don’t need much water and can be watered only every ten to 14 days. Their thorns are very dull when compared to other cacti. They grow slowly, which means that any new flowers or buds on the plant will be colorless. They need to be placed in bright areas.