Bulliform cells in Loudetiopsis chrysothrix (Nees) Conert and Tristachya leiostachya Nees (Poaceae): Structure in relation to function

This work reports anatomic and ultrastructural characteristics of bulliform cells in Loudetiopsis chrysothrix (Nees) Conert and Tristachya leiostachya Nees. Both the species presented leaf rolling under water stress. The main characteristics observed in these cells were: periclinal wall thinner than the adjacent epidermal wall; abundance of pectic substances in cuticular layer; sinuous anticlinal walls with ramified plasmodesmata; vacuome formed by a developed vacuole or innumerous small vacuoles; abundance of phenolic substances and oil drops. These characteristics suggested the involvement of bulliform cells in the mechanism of foliar involution in the studied species.