It is one of the largest of the Gasteria species, second only to Gasteria acinacifolia in height.
It has smoother, thicker, wider, darker leaves than its relative, and forms solitary, robust rosettes of stiff, sharp, triangular leaves.

It can be distinguished from its closest relatives by the unusually sharp, heavily-serrated, white margins on their leaves.
The leaves are a distinctive mottled, dark green colour, with a smooth surface (though juvenile plants' leaves are rough).

The leaves of fully grown plants are often channeled on the upper side, with sharp edges, and (like its relatives) a keel on their lower side.

The erectly-branched inflorescence is often over a meter in height, with pink-green flowers and appears between November and February.
The specific epithet, excelsa, means "lofty" or "high" in Latin.
It refers both to the great height of the plant's inflorescence, as well as to the high cliff-face habitat of this species.

They are popular as ornamental plants for containers, but have a very large root system.
It is one of the largest of the Gasteria species, second only to Gasteria acinacifolia in height. It has smoother, thicker, wider, darker leaves than its relative, and forms solitary, robust rosettes of stiff, sharp, triangular leaves.
It can be distinguished from its closest relatives by the unusually sharp, heavily-serrated, white margins on their leaves. The leaves are a distinctive mottled, dark green colour, with a smooth surface (though juvenile plants' leaves are rough). 
The leaves of fully grown plants are often channeled on the upper side, with sharp edges, and (like its relatives) a keel on their lower side.
The erectly-branched inflorescence is often over a meter in height, with pink-green flowers and appears between November and February. The specific epithet, excelsa, means "lofty" or "high" in Latin. It refers both to the great height of the plant's inflorescence, as well as to the high cliff-face habitat of this species.
They are popular as ornamental plants for containers, but have a very large root system.
Gasteria excelsa