The leaf-like pattern (the folium[4]) on the dorsum is brownish with some whitish transverse lines towards the posterior.

Xysticus ulmi is sexually dimorphic; males are darker than females and the patella and femora of the first and second legs are black.

[5] Xyticus ulmi is usually found on low vegetation and in the ground layer in damp places, especially in wetlands and rough grassland, but in it can also occur in ditches alongside arable fields, hedges, roadside verges and woodland especially where the canopy is not closed, such as coppiced areas.

[2] Like other members of the genus it is an ambush predator, lying in wait for invertebrate prey.

The males subdue the females by stroking their legs then tie them down with silk before mating.