|  | juice watery; NOT [juice milky] | 
      |  | leaves with spiny margins | 
      |  | bracts of involucre NOT dry or
        parchmenty, usually green | 
      |  | some bracts spiny tipped; NOT [involucral
        bracts with hooked bristles] | 
      |  | receptacle densely bristly; NOT
        [receptacle naked] | 
      |  | flower heads with all florets tubular;
        NOT [flower heads with florets both tubular and ligulate]; NOT [flower
        heads with all florets ligulate] | 
      |  | stamens united to form a tube around the
        pistil | 
      |  | pappus of capillary bristles; NOT [pappus
        of scales, or of awns, or a crown or none] | 
      |  | pappus hairs much longer than achene | 
      |  | pappus bristles plumose; NOT [pappus
        bristles naked or merely minutely barbellate or merely roughened] |