Morning Glories: First Bloom - Quintana Roo, Mexico MG, 1 by atenkley

atenkley wrote:
I've decided on 4 different measurements for my Morning Glory flowers. The first three are depicted on this first photo.

Corolla width: the diameter of the extended corolla.

Throat width: the distance across the throat between the first points of contact (tangents) as one lowers a straight edge along the diameter of the flower.

Internal tube length: the distance a narrow pointed straight instrument (small bamboo skewer!) travels down to the internal base of the tube from the straightedge across the flower diameter.

External tube length: the distance from the base of the sepals to the point where the ribs part and the minor fold line begins. (shown in next picture)