Tickseed
The photo shows tickseed plants (Bidens pilosa, family: Asteraceae ) "rage" in an open field. The name tickweed comes from the seeds that stick on textiles by their sharp hooks. The tickseed belongs to Asteraceae family whose composite or head flowers are comprised of many disk and ray flowers. The fruit type of the Asteraceae family is called cypsela. The photo shows germinating tickseed seed. After they germinate, in a matter of several hours, root hairs appear.
2005-11-21