"When the carpels consist of several whorls on the same plane, the individuals of contiguous whorls follow the same law of alternation, as is exhibited in Fig. 133, in which a represents the axis, b b the whorl contiguous to it, and c c the exterior whorl."—Darby, 1855

Two Whorls of Carpels

"When the carpels consist of several whorls on the same plane, the individuals of contiguous whorls…

Repeating pattern with 2 elements.

Repeating Pattern

Repeating pattern with 2 elements.