ClipArt ETC
"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.