Historical clue formulations

• Furniture hardwood — 2023-10-24
• Birch relative — 2023-05-02
• Tree in the birch family — 2021-03-22
• Catkin-producing tree — 2020-10-19
• Wood used to make electric guitars — 2018-06-22
• Wood that makes up the foundation of much of Venice — 2017-03-19
• Birch relative often used in electric guitars — 2016-08-16
• Tree with catkins — 2016-06-26
• Guitar-making wood — 2016-03-18
• Tree with catkins — 2015-05-14
• Tree with catkins — 2012-04-20
• Material for many electric guitar bodies — 2010-03-12
• Tree sacred to the Druids — 2009-12-30
• Tree with catkins — 2009-04-14
• Tree with catkins — 2009-03-24
• Tree with catkins — 2008-05-02
• Black ___ (winterberry plant) — 2007-04-13
• Tree with catkins — 2006-06-14
• Tree with catkins — 2005-09-13
• Tree with catkins — 2003-10-21
• Birch relative — 2003-10-05
• Tree with catkins — 2003-03-23
• Charcoal wood — 2002-02-01
• Tree with catkins — 2001-09-22
• Tree with tanning bark — 2000-07-09
• Birch relative — 2000-03-22
• Birch relative — 1998-07-27
• "Red" tree — 1997-09-02
• Tree of the birch family — 1996-09-30
• Tree in a thicket — 1996-03-24
• Birch — 1994-10-22
• Birch kin — 1993-12-02