Historical clue formulations

• What has spikes of interest? — 2023-06-03
• Prickly plant — 2020-10-19
• Prickly one — 2013-11-27
• Low-maintenance potted plant — 2013-03-31
• Bit of desert flora — 2011-10-03
• Desert water source — 2009-09-03
• Peyote is one — 2006-03-22
• It has points in Arizona — 2005-08-01
• Xerophyte — 2004-08-07
• Natural sticker — 2002-10-05
• Sticker — 2002-08-03
• It has points in Arizona — 2002-03-18
• Saguaro — 1998-03-23
• Prickly pear, e.g. — 1998-01-29