Field Thistle (Cirsium discolor) 9/19/2009 Eastern Neck NWR, MD

more info on Thistle IDs:
http://pwr.philcobill.com/aste/cirsium-discolor.html

https://www.minnesotawildflowers.info/flower/field-thistle
-often heavily branched in the upper plant
Tall Thistle (Cirsium altissimum)
upper, and often lower, leaves are not lobed and more coarsely toothed
"non-native thistles are distinguished by their sharp spines, especially along the stems.
While most references give a height of Field Thistle up to 7 feet, we've seen plants
rather taller."