  | 
         herbs, or low spineless shrubs; NOT
        [spiny shrub, 1-2 m high]  | 
        | 
         plants not prickly; NOT [plant prickly
        from the spine-tipped thread-like leaves and from bracts]  | 
        | 
         stems not fleshy  | 
        | 
         stems not jointed  | 
        | 
         stems tomentose to densely
        glandular-villous; NOT [stems not tomentose to densely villous]  | 
        | 
         leaves mostly alternate; NOT [leaves
        opposite]  | 
        | 
         leaves not reduced to scales  | 
        | 
         leaves narrow, linear; NOT [leaves broad,
        often hastate], NOT [leaves flat, wavy-edged, ovate]  | 
        | 
         leaves usually turning red when mature  | 
        | 
         NOT [flowers axillary and sunk into the
        fleshy stem]  | 
        | 
         flowers not subtended by scarious bracts  | 
        | 
         flowers lacking bracteoles; NOT
        [pistillate flowers with a pair of bracteoles, occasionally 3]  | 
        | 
         calyx with 5 sepals  | 
        | 
         sepals greenish, herbaceous or fleshy;
        NOT [sepals scarious, dry and membranous]  | 
        | 
         calyx in fruit developing horizontal
        scarious wings but not slender hooked spines  | 
        | 
         flowers perfect or pistillate  | 
        | 
         5 stamens
            |