Fasciated Fireweed (Chamerion angustifolium)

Observation by Kelly Matthews:

Flat, wide stem with many buds, curling.

Jessie Moan, Forest Health Technician with the University of Alaska Fairbanks Cooperative Extension, writes:

This strange growth pattern is called fasciation. Fasciation is essentially abnormal cell growth and can be triggered by everything from pathogens, insects, mechanical damage, genetic mutations, or environmental causes. Most often fasciation occurs "by chance." More information can be found at the University of Wisconsin-Madison Cooperative Extension website.

Comments from LEO Editors:

There are many resources, and interesting photos, available that describe plant fasciation. According to the University of Arkansas Cooperative Extension Service, fasciation can occur in any type of plant and begins from a mutation in a single cell in the central zone of the meristem (areas of the plant where growth takes place). The mutation can be caused by a variety of stimuli, and is relatively rare. Erica Lujan