Tulista marginata, formerly known as Haworthia marginata, is a rare slow-growing succulent that forms stemless rosettes of erect to... xGasteraloe 'Flow' is a slow-growing succulent that forms a rosette of sturdy deep green leaves covered with white bumps. Tulista opalina (formerly Haworthia opalina) is a small succulent that forms a rosette with thick, fleshy and stiff, light green leaves. xGasteraloe Twilight Zone', a small succulent that forms rosettes from dark green leaves with tiny white marks, is attractive.