President Donald J. Trump (L) and First Lady Melania Trump (2R) pose with French President Emmanuel Macron (R) and his wife Brigitte Macron (2L) as they participate in a tree planting in front of the White House in Washington, DC, USA, 23 April 2018. President Macron will be in DC for three days for a state visit at the White House and an address to a joint session of Congress on 25 April. EPA-EFE/SHAWN THEW 
A week ago, at the beginning of Macron's visit to Washington, the French president joined his American counterpart to throw handfuls of soil on the roots of a young oak tree as their respective first ladies looked on
It was a symbolic gesture: the tree came from a northern French forest where 2,000 US Marines died during the First World War.
But a few days later, the plant was nowhere to be seen.
Amid fervent speculation, France on Sunday came through with an explanation: the tree, now not just a plant but a symbol of US-French relations, had been placed in quarantine.
"It is a quarantine which is mandatory for any living organism imported into the US," Gerard Araud, French ambassador to America, wrote on Twitter.
"It will be replanted afterwards."
When a follower fired back that the caution seemed a bit late -- given that the tree had already been planted -- the diplomat went on to confirm that the roots had been enclosed in plastic. DM