Historical clue formulations

• Arboreal symbol of Massachusetts — 2023-05-08
• State symbol of Massachusetts — 2022-11-06
• It has furrowed gray bark — 2021-07-10
• State symbol of Massachusetts — 2018-10-15
• One state symbol of Massachusetts — 2017-04-23
• State symbol of Massachusetts — 2013-05-26
• Target for a certain bark beetle — 2012-10-01
• Stately thing in Browning's "Oh, to be in England ..." — 2009-06-11
• Bay State emblem — 2002-01-24
• Victim of a Dutch disease — 2001-11-14
• Bay State symbol — 2001-06-16
• A Massachusetts symbol — 2000-10-01
• Site of a William Penn treaty with Indians — 2000-03-11
• Home to some bark beetles — 1999-01-30
• Shade maker — 1996-07-20
• Shade maker — 1995-03-29