Effect of time of harvest on physiological maturity and kenaf (Hibiscus canabinus) seed quality

The presence or absence of micro-characters in plant system like calcium oxalate crystals, trichromes, hairs etc. has been used for understanding the evolutionary relationships of plant species. The size and appearance of calcium oxalate crystals (COCs) can differ within families, genus, and species and these characteristics might be genetically controlled. We have studied the calcium oxalate crystals in the different plant parts (leaves, stems, petiole, corm, and root) of some selected species belonging to the family Araceae. The selected plants belonged to different habitats like marshy, semi aquatic, terrestrial and were mostly herbs, shrubs, and climbers. Among the selected species, two species are edible and economically important. Edibility of petiole, leaves, stems and corms depends upon the frequency and intensity of the calcium oxalate crystals. Two types of calcium oxalate crystal (Type-I and IV) were observed which are mostly species specific. The significant diversity in both the crystals and idioblast point of view were observed. In rare aroid like Lasia heterophylla [Type-I] and very frequent aroid (edible) Amorphophallus campanulatus [Type IV] both having longer crystals (COCs) and on the other hand in case of Dracontium nivosum [Type-I] andColocasia esculenta [Type-IV] having shorter crystals (COCs). The frequency of crystals is probably related with the habit, habitat and also the environmental conditions.   Key words: Calcium oxalate crystals (COC), idioblast, druse, Araceae.