Keel: long narrow ridge over the length of a flat or curved surface;
Keel formed by the two lower petals in papilionoid flowers in Leguminosae/Fabaceae, these usually partly united or adherent.
A keel; the two anterior petals of a papillionaceous flower.
A structure shaped like the bottom of a boat, e.g. the cartilage at the point where the trachea branches into the bronchi.
Branch point of the windpipe (trachea) into the right and left mainstem bronchi.
Anatomical structure of a central ridge on a tissue surface.
A keel-like structure, such as the keel-shaped cartilage at the bifurcation of the trachea into the two main bronchi.
A structure with a projecting central ridge.