Question

What is a leaf blade?​

Answer 1

Especially a leaf of grass or the broad portion of a leaf as distinct from the petiole. The photosynthetic part of a leaf.

Answer 2

A leaf is the principal lateral appendage of the vascular plant stem, usually borne above ground and specialized for photosynthesis. The leaves, stem, flower and fruit together form the shoot system. Leaves are collectively referred to as foliage, as in "autumn foliage".