MORPHOLOGICAL AND ANATOMICAL STUDY OF THREATENED ENDEMIC HELIOCARYA MONANDRA BGE. (BORAGINACEAE) IN IRAN

Heliocarya monandra is a rare endemic species of Boraginaceae that grows in a limited area in central Iran. Since there has been no comprehensive study of this species, morphological and anatomical properties of it were investigated. For this, plant samples were collected from a locality on the Soffeh Montain in the south of Isfahan city in central Iran. Sections of leaf, stem and root were taken manually and prepared according to the current laboratory methods for light microscopic examination. The measurements were done in at least 5 replicates. Some properties of fruit and seed were described. Fruit consisted of an ovoid or orbicular one-seeded nutlet with 4-6 (-7) mm length, 2.5-4 mm width and 0.8-1 mm thickness. Seed was also 1.8-2 mm long, ovoid, with a curved beak. The leaf was isobilateral with anomocytic stomata. The root showed secondary structure. The stem had also both primary and secondary tissues. The results in morphology and anatomy were in agreement with general characteristics of the family Boraginaceae except for some differences. Details of fruit and seed are reported for the first time. Fruit characters are especially important to clarifying taxonomic relationships in the family. According to field observations, there is only one population of this species in Isfahan province and it seems that this population is at risk of disappearing in nature.