A female St. Andrew's Cross Spider in its distinctive web. Its name derives from the characteristic zigzag, cross-shaped web decorations, known as stabilimenta, that form an X with a hollow center, in which the spider positions itself by aligning its legs in pair with each of the zigzag web decorations.

St. Andrew's Cross Spiders display sexual dimorphism, with females being considerable larger than males. Lacking the bright colours of adult females, juvenile females are rather pale brownish grey with just a few with dots, and reside on a web with a circular pattern of zigzag stabilimenta (fig.).