Rudall & Chase, Systematics of Xanthorrhoeaceae sensu lato 
However, they have the typical structure of silica bodies and lack the polarising 
properties of calcium oxalate crystals. X-ray and SEM examination effectively 
demonstrates the silicaceous nature of these bodies. Silica is also present in the 
epidermis of Dasypogon (Figs 3e, 5c) and Calectasia in the form of fine silica sand or 
amorphous crystals, in most epidermal cells in Dasi/pogoii, although less frequent in 
Calectasia. Silica is always absent from the other genera examined, including Loimndra 
and Xanthorrhoea, both of which have polyhedral styloid-like calcium oxalate crystals. 
In Xanthoi rhoea these polyhedral crystals are frequently epidermal, unusually for 
Asparagales, but X-ray analysis demonstrates that they are not silica (Fig. 5d). In 
Xerolirion leaves, although epidermal cells appeared to contain bodies, these were 
extremely small, and we were unable to confirm the presence of silica. 
Fig. 4. Leaf anatomy, a-c, Xerolirion divaricata: a,b, leaf TS, with sclerenchyma girders and subepidermal 
sclerenchyma (s) and raphide idioblast (ri); c, leaf surface, with anomocytic stomata; d,e, Rommida 
grallata: leaf TS, with small sclerenchyma bundles (s). Scale bars = lOOpm, except in c = 50pm. 
