Historical clue formulations

• Tree whose leaves are eaten by [circled letters] — 2026-06-21
• Its leaves are eaten by giraffes — 2025-10-26
• Traditional wood for a ukulele — 2025-05-31
• Tree that yields gum arabic — 2023-08-13
• Thorny savanna tree — 2023-05-30
• Thorny tree — 2021-10-25
• Thorny tree — 2021-06-16
• Tree that's a favorite of giraffes — 2021-03-31
• Food for a giraffe — 2020-04-17
• Gum arabic source — 2018-06-14
• Tree favored by giraffes — 2017-08-19
• Mimosa, for one — 2015-07-26
• Gum arabic source — 2015-05-28
• Thorny tree — 2015-03-10
• Tree in a giraffe's diet — 2014-09-18
• Whistling thorn, e.g. — 2012-03-16
• Tannin source — 2007-11-25
• Gum arabic-yielding tree — 2007-11-20
• Mimosa family member — 2004-12-19
• Mimosa family tree — 2004-10-10
• Small flowering tree — 2003-08-24
• Source of gum arabic — 2002-08-29
• Savanna shrub — 2002-06-28
• Mimosa, for one — 2001-10-28
• Mimosa-family tree — 2001-06-28
• Australia's national blossom — 2001-05-06
• Gum arabic tree — 2000-12-24
• Decorative tree — 2000-05-16
• Locust tree — 1999-12-09
• Gum arabic source — 1999-04-18
• Greenish-yellow hue — 1997-08-31
• Flowering shrub — 1996-07-21
• Locust — 1995-12-26