There are some plants that are colloquially referred to as "milk plants" because they produce a milky or latex-like substance.
Rubber tree is famous for its latex, extracted from its bark and widely used in industry.
Milkweed plants produce a milky latex sap, and they are an important food source for monarch butterfly caterpillars.
Poinsettias are popular ornamental plants known for their colourful bracts. They also produce a white, milky sap, which can be irritating to the skin and mucous membranes.
Dandelions have a milky sap in their stems and leaves. They are considered weeds in many lawns and gardens.
Many species of Ficus, including the common houseplant Ficus elastica (rubber plant), produce a milky latex sap.