Sansevieria plants, commonly known as snake plants or mother-in-law's tongue, are characterized by their erect, sword-shaped leaves that grow from a basal rosette. These succulent plants, native to Africa and Asia, are known for their resilience and low maintenance. They typically feature dark green leaves with light gray-green bands, though variations exist with different patterns and shapes. 

Here's a more detailed description:

Leaves:

The defining feature of Sansevieria is its stiff, erect leaves that can be quite long, up to 70-90 cm in length and 5-6 cm in width. These leaves are often described as sword-shaped or lance-shaped, and can have a variety of patterns, including green and whitish-green bands, or even variegation. 

Growth Habit:

Sansevieria plants form dense clumps from a spreading rhizome or stolons. Some varieties, like the "bird's nest" sansevieria, grow in a rosette formation. 

Flowers and Fruit:

While not always prominent in indoor settings, Sansevieria plants can produce small, fragrant, greenish-white flowers in the spring, followed by bright orange berries. 

Toxicity:

Snake plants are mildly toxic to humans, animals, and cats. The leaves contain a poison that can cause swelling and numbness on the tongue if eaten in large doses.