These specimens may be X. johnsonii, however, I can detect no morphological characteristics that separate these from X. glauca or X. malacophylla based upon the photographic images. A description of the leaf colour (green or glaucous) and characteristics (easy to snap when flexed or resistant to break, or hard and resistant when compressed between thumb and forefinger or spongey-like), and cross-section leaf shape (taken mid-way the length of the leaf), could be used as determinants to assist with a species ID.