Trypanosomatid flagellate in the Phloem of diseased coconut palms.

Ultrastructural observations of the phloem of coconut palms affected by "hartrot" disease in Suriname have revealed the presence of the plant-infecting flagellate Phytomonas in mature sieve tubes. The occurrence of these flagellates during the earliest symptoms of the disease and the correlated increase and spread of the flagellates in the phloem as the disease progresses suggest that the organisms may be pathogenic to the palms.