Rhythms of mistletoe

The temporally and spatially inhibited growth of mistletoe is subjected to specific rhythms during the course of the seasons.

While growing, the young mistletoe branches demonstrate synchronous swinging motions from late May until late June. These loosen the annual shoots from their original vertical orientation, after which they align with the center of the mistletoe bush.

At the same time the organs of new mistletoe branches are produced in the lateral buds which will develop the following spring. After the growth of a pair of leaves the vegetative development stops in mid-June with the growth of a flower head instead of additional leaves.

The berries reflect this change by accumulating nutritive tissue in the mistletoe seed until the end of June, followed by the development of mistletoe embryos in July. Rhythmic changes in the shape of the developing mistletoe berry indicate that the mistletoe’s growth also correlates with the path of the moon across the zodiac constellations.