These characteristics pertain to the interior part of the leaf blade as you move inward from the margins. The descriptive terms include cupped, twisted, folded, wavy, corrugated and flat. The modifier words applied include lightly, moderately, deeply or intensely. So, a leaf might be described as intensely corrugated or deeply cupped, for example.

Corrugation in hosta leaves involves wrinkles that extend from the outer edge of the leaf into the center rib. This distinguishes this trait from wavy or rippled which only occur near the edge of the leaves. Heavy corrugation gives the plant a generally coarse texture and feeling of great mass.

As with all traits, defining the extent of this leaf characteristic is subjective. We have divided hostas into three categories based on information from available sources including registration forms:

Heavily Corrugated, Moderately Corrugated or Slightly Corrugated

In some hostas, the cells at the edges of the leaf grow more slowly than those in the center of the leaf blade. This results in a cupping effect which can from Heavily Cupped, Moderately Cupped or Slightly Cupped depending on the depth created.

Flat - Leaves in this category are not flat as a board. Rather, they are NOT conspicuously rugose, cupped, contorted or undulate along the margins.

Very Flat  -  Moderately Flat  - Slightly Flat

Folded - These are leaves that are not very rigid and may actually fold over along the margins of the leaf blade.

Piecrust - Essentially flat but have closely spaced marginal undulations like the rim around the top of a homemade apple pie. Distinct, regular, almost uniformly spaced, and plainly recognized undulations on all mature leaves.

Twisted - As the name implies these leaves have a twisted effect due to the uneven development of cells in the center of the leaf blade.

Wavy- Leaves are relatively smooth but are very wavy and undulate. Several broad waves on the leaf sometimes confined to the margins. Leaf tip may be slightly twisted.

Heavily Wavy  -  Moderately Wavy  -  Slightly Wavy

Heavily Rippled  -  Moderately Rippled  -  Slightly Rippled