source: CUPIC

Notice the clear edge of the allelopathic ring surrounding the tree.

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Black walnut has large round fruit. It contains a dye, and the nut is very hard to extract.

Read more about Black walnut has large round fruit. It contains a dye, and the nut is very hard to extract.

The density of seedlings seen here is not unusual. Maybe an animal/insect collection. (Ontario, Canada)

Read more about The density of seedlings seen here is not unusual. Maybe an animal/insect collection. (Ontario, Canada)

Distinctive shape and speckled orange color of common jewelweed in Illinois.

Read more about Distinctive shape and speckled orange color of common jewelweed in Illinois.

The "prolific" number of stamens is a good way to remember the species name.

Read more about The "prolific" number of stamens is a good way to remember the species name.

A typical, multicolored population of dame's rocket along an Ithaca road.

Read more about A typical, multicolored population of dame's rocket along an Ithaca road.

The airy seed head of winter bent grass, taken in Ontario Canada.

Read more about The airy seed head of winter bent grass, taken in Ontario Canada.

Fine textured winter bentgrass in Ontario, Canada

Read more about Fine textured winter bentgrass in Ontario, Canada

Danthonia spicata, taken in Colorado

Read more about Danthonia spicata, taken in Colorado

Serrated leaflets helps to distinguish from F. rubra with lobed leaflets. (Romania)

Read more about Serrated leaflets helps to distinguish from F. rubra with lobed leaflets. (Romania)