Observations of flagellate protozoa (Phytomonas sp.) in the xylem of Euphorbia lasiocarpa in Ecuador

In Asclepias curassavica L. and Euphorbia lasiocarpa Kl. flagellated protozoa (Phytomonas sp.) occur in laticiferous tubes. In Euphorbia lasiocarpa, but not in Asclepias curassavica, they also occur in the xylem and the intercellular spaces. The significance of these findings in relation to possible arthropod vector transmission of Phytomonas is discussed.