Milkweed

Common milkweed is important because many insects survive on it, and several only eat milkweed.  Similar to yesterday's butterfly weed blip, milkweed sap contains a toxin (glycoside) which is harmful to some animals but not to Monarch butterfly caterpillars and other insects which eat milkweed as a primary food source.  Nectar and pollen do not contain the toxin.

The fruits of the milkweed are probably more familiar than the flowers.  Milkweed fruits are green pods which turn brown.  When the pods burst open, fluffy seeds are freed.