The term 'LATEX SOURCE' can be broken down into three crossword solutions: MILKWEED (8 letters), ULE (3 letters), and RUBBERTREE (10 letters). MILKWEED is a type of plant that produces a milky sap, which is used to make latex. ULE is a type of rubber tree found in tropical regions of South America. RUBBERTREE is a species of tree native to the Amazon rainforest that is used to produce rubber. All three of these solutions are related to the production of latex, which is a natural rubber material used in a variety of products.