The ever-increasing importance of vegetable natural fibers on the global scale, the comparatively low production of this group of fibers, and the growing fiber imports by the Iranian textile industry have required numerous studies in recent years to be carried out on long natural cellulosic fibers extracted from Typha australis plant leaf. In this study, such tensile properties of the fiber under study as tenacity, modulus, elongation and work of rupture, X-ray and FTIR are investigated by alkali retting at $100^{circ}C$ for 2 and 4 h. It is found that Leafiran is lignocellulosic with a tenacity approximately 25-40 cN. Tex-1, a linear density of about 4 tex, and a crystallinity of about 60 %, which are all considered to be suitable properties compared to those of other natural cellulosic fibers.