FIGURE 4.

Fibers in the middle cortex of P. nudum. (A,B) Longitudinal sections of the first order shoot from stele and cortex, correspondingly, stained with 0.5% toluidine blue; (C) elongated cells with pointed ends (marked by arrows) isolated from cortex tissues of the first order shoot by maceration and stained with 0.5% toluidine blue; (D) partially macerated cortex tissues stained with DAPI (nuclei in elongated cells of middle cortex are marked by arrowheads). E – epidermis, IC – inner cortex, MC – middle cortex, MCC – middle cortex isolated cells, OC – outer cortex, OCC – outer cortex isolated cells, T – tracheid, SE – sieve element. Scale bar 500 μm.