'Treillage' is the French word for trellis, and here we use the term to designate particularly artistic trellises and lattice-work. In Baroque times, the espalier system was often designed very artfully, sometimes considered more significant than the plants they should support. The 'treillage' emerged as a special type of garden art. The trellises were particularly complex and ornamental and their significance went far beyond the mere trellising of plants. Ornamental trellises were an assembly of slats or stakes in the shape of a pavilion or arbour. The treillages were also on facades, but they often went ungreened and were appreciated just for themselves, e.g. in the Wilhelminian period.