Es una especie de víbora venenosa. Dentro de su rango, es una causa importante de mordedura de serpiente. El nombre específico, alternatus, que en latín significa "alternar" es aparentemente una referencia a las marcas escalonadas a lo largo del cuerpo.
Actualmente no se reconoce ninguna sub especie
c. 10 cm length, and just under 2 mm diameter. Found on paved area of garden, where it was clearly having trouble moving about, writhing and not making much progress. On a flat surface it would throw loops and progress with difficulty. Its movements didn't resemble those of an earthworm, perhaps being more limited to one plane (lateral twisting rather than coiling in all directions). In a jar it was clear how it moved the head and front part of body to investigate, quite different from a worm and more snake-like. Released into some long grass, where it moved with much more ease, melting away down among the bases of the grasses.