Historical clue formulations

• Supporting stalks — 2016-03-29
• Frond supporters — 2013-01-05
• Mushroom supporters — 2010-01-02
• Mushroom stalks — 2008-09-28
• Mushroom stems — 2007-12-09
• Mushroom stems — 2002-01-06
• Mushroom stems — 1996-05-31