Mitre Aloe

The Aloe mitriformis, commonly known as the Mitre Aloe and now formally treated as Aloe perfoliata, is a sprawling South African aloe that creeps outward on long decumbent stems, each tipped with a compact rosette of thick, triangular, blue-green leaves edged in bright yellow teeth. Dense scarlet flower heads are carried in summer.
The creeping habit makes it behave more like a succulent ground cover than an upright aloe, and it will tumble over walls and down banks. It is used on retaining walls, slopes, rockeries and in raised planters.
The Mitre Aloe is the aloe to use where the design wants something to spill over an edge rather than stand up in a bed.