Involucel. A secondary involucre, as that of an umbellet in Umbelliferæ.
Involucellate. Having an involucel.
Involucral. Belonging to an involucre.
Involucrate. Having an involucre.
Involucre. A circle or collection of bracts surrounding a flower cluster or head, or a single flower.
Involute. Rolled inward.
Irregular (flower). Showing inequality in the size, form, or union of its similar parts.
Julaceous. Resembling a catkin in appearance.
Keel. A central dorsal ridge, like the keel of a boat; the two anterior united petals of a papilionaceous flower.
Kidney-shaped. Crescentic with the ends broad and rounded; reniform.