A leaf is that part of a plant which gathers light and provides shade. The default heraldic leaf seems to be a generic sort, with a simple elliptical shape; as heraldic charges, this sort dates from c.1300 [ANA2 249]. However, leaves of all shapes are found in period armory: elm leaves in the arms of Elmerugge or Elmridge, c.1285 [ANA2 289], oak leaves in the arms of Tregruthken, 1335 [DBA2 381], holly leaves in the arms of Eruyn or Irwin, 15th C. [Scots 48v], linden leaves in the arms of von Lynden or Linden, c.1370 [Gelre 43v; also Siebmacher 141], ivy leaves in the arms of Yve, c.1470 [DBA2 43].
As may be seen, the type of leaf was frequently chosen for the sake of a cant – Yue had yew leaves, Hesilrigg had hazel leaves, Malherbe had nettle leaves, &c – and without the cant, it is often difficult to determine the type of leaf being used. Period rolls show the same arms drawn with different types of leaves. The Society grants difference between some types of leaf, but not others.
Leaves have their stems to base by default, but there are frequent period examples of leaves inverted as well. For related charges, see card-pique, foil, nesselblatt, seeblatt, slip, vine. See also feather.
Ann of the Tall Trees bears: Vert, an oak leaf fesswise argent.
Avisa of Rideja bears: Per saltire Or and argent, a maple leaf vert.
Tamara iz Kiev bears: Argent, three birch leaves vert.
Seved Ribbing bears: Per fess azure and Or, three linden leaves counterchanged.