Sansevieria sinus-simiorum, commonly known as 'Malawi Bat' or 'Super Bat,' is an herbaceous perennial leaf-succulent plant. It is native to Malawi and possibly Zimbabwe. The type locality for this species is approximately 2 km south of Monkey Bay, Malawi. The plant was first described by Chahin and bears his name as a synonym.

The leaves of Sansevieria sinus-simiorum are upright to somewhat recurved, hard, and thick. They have a cylindrical shape with a massive "D" section, reaching lengths of 60-90 (-110) cm and widths of almost 5 cm. The leaves have a dark green to brownish-grey color, with shades of grey on young leaves and nearly uniform green on mature leaves. Unlike other "bat" Sansevierias, this species has impressed black-green lines running longitudinally on the front and back of the leaves. The leaf channel is not as deep, and the edges are less sharp, except at the leaf tip.

The plant produces purplish-white flowers that emerge close to the ground from the rhizomes. However, due to its slow growth, flowering may be relatively rare.

In cultivation, Sansevieria sinus-simiorum is considered easy to grow and requires minimal care. It is typically grown in containers and should be underpotted. A well-draining soil mix consisting of three parts loam to one part pumice is recommended. The plant is highly drought-tolerant and should be watered sparingly, about every other week during the growing season and once a month in winter. Fertilization with a balanced fertilizer is done once during the growing season.

Regarding lighting, Sansevieria sinus-simiorum can tolerate low light levels but thrives and flowers best when provided with bright light or even full sun. In mild to tropical climates, it prefers semi-shade or shade. It is not frost-hardy and should be protected from freezing temperatures. In frost-free areas, it can be grown outdoors on covered patios or under areas where it won't receive winter rainfall. The plant exhibits excellent heat tolerance.

Propagation of Sansevieria sinus-simiorum can be achieved through cuttings or divisions. Cuttings should be at least 10 cm long and inserted into moist sand. A rhizome will emerge at the cut edge of the leaf, indicating successful propagation.

Please note that the above information is based on the available details about Sansevieria sinus-simiorum up until September 2021, and there may have been additional research or updates since then.