SUMMARYThe latex ofAsclepias curassavicaL. was shown to contain 40–60 mg.ml–1cardenolides and 0.4–0.6 mg.ml–1esterified triterpenes. The dynamics of14C incorporation of D‐glucose‐U‐14C, acetate‐1‐14C and mevalonate‐2‐14C into esterified triterpenes and cardenolides in excised stem parts have been studied. The results obtained indicate that glucose is a very effective precursor in latex triterpene synthesis. The three precursors used were only slightly involved in cardenolide synthesis. The results are discussed in relation to the view that both latex constituents probably have differe