Comparative vegetative anatomy of three Elaeocarpus species from the Western Ghats, Southern India

The vegetative anatomy of Elaeocarpus angustifolius Blume, Elaeocarpus tuberculatus Roxb., and Elaeocarpus variabilis Zmarzty were investigated to illustrate anatomical variations. Plant materials were free-hand sectioned using a razor blade and stained with different staining solutions. The maceration technique was used to assess stomatal characteristics. Elaeocarpus leaves have abaxial epidermis with paracytic stomata and curved anticlinal walls in E. angustifolius, straight walls in other two species. Trichomes were absent in E. angustifolius.hav Mesophyll dorsiventral, midvein cortex contains starch grains, and vascular tissues enclosed by thick-walled sclerenchymatous cells. The petioles of all the three species possess unicellular epidermal hairs, collenchymatous hypodermis, and cortex containing druses and crystals, and vascular tissue enclosed by sclerenchymatous fibers. Water-storage cells are absent in petioles of E. angustifolius. Anatomical features of Elaeocarpus stem include epidermal hairs, epidermis covered by thin cuticle, the collenchymatous hypodermis and vascular integrity with entire cylinder enclosed by sclerenchymatous fibers. Pith contains water-storage cells. Starch grains absent in the pith cells of E. tuberculatus. The roots of Elaeocarpus possess unicellular root hairs, cortex 12-14 layered in E. tuberculatus and E. variabilis and 10-12 layerd E. angustifolius, Endodermis O-thickened and pericycle single-layered in all the examined Elaeocarpus species. Vascular bundles are arranged radially. Lignin deposition occurred in stellar region of roots. Water-storage cells present in the stelar regions of E. variabilis. The study revealed significant anatomical differences between the three Elaeocarpus species and most of these anatomical features may be used as markers for the identification of these species. RESEARCH HIGHLIGHTS: Comparative anatomy of three south Indian Elaeocarpus was studied. Leaf mesophyll layers varied in all the Elaeocarpus species. Crystals was present in petiole of all examined Elaeocarpus species. Starch grains was absent in stems of E. tubercuatus, but present in E. variabilis. Water-storage cells observed in stellar region of E. variabilis.