Wood and bark anatomy of Azima tetracantha Lam. (Salvadoraceae) with description of its included phloem

The anatomy of the secondary phloem and xylem of the large shrub Azima tetracantha Lam. (Salvadoraceae) from Madagascar, has been studied. The presence of included (interxylary) secondary phloem, previously only known in the two other genera of this family, Dobera and Salvadora. has been demonstrated. The phloem strands in the secondary xylem belong to the forarainate or Strychnos type. Sieve elements of the normal external secondary phloem are in contact with the vertical included secondary phloem strands by means of horizontally oriented ones within the wider rays. A threedimensional network of sieve elements exists throughout the secondary stem tissue, interrupted by the cambial zone.