I've also been to visit the Ankerwyke, or Ankerwycke Yew. This tree is included in Strutt's Sylva Britannica, and also in another set of fine prints of trees - Henry William Burgess's Eidodendron (published in a folio edition in 1829).
Here are the Strutt and Burgess images side by side. You'd hardly think they were the same tree, would you? The explanation, I think, is that (a) Burgess took a rather more romantic, less scientific approach to his trees than Strutt, and (b) that when Strutt drew the tree, it had been trimmed - a relic of the fashion for topiary which was dying out by this time. When Burgess drew it several years later, the estate had changed hands and the new owner was letting the tree spread out its foliage freely. But both artists show it in a parkland setting, with open space around it. Its situation today is very different: the area is very overgrown and it's not possible to stand back and photograph the tree as a whole. But the trunk of the tree looks quite like Strutt's rendition of it.
This tree has recently become very famous because of the theory that it was the site of the signing of Magna Carta. A fallen branch beside the tree had received "offerings" of fresh flowers when I visited. Our modern attitude to these "venerable" ancient trees has much in common with the attitudes that caused Strutt and Burgess to produce their large, finely drawn "portraits." They were associated then, as now, with the continuities in British history and a sense of the tree as sacred.
You can read a review of it hereFrom c. 2010-2017, I was engaged in research for a book on trees in British art, asking questions, such as: how does the interest in trees develop, how do ideas change over the 18th and 19th centuries? I looked at drawing manuals, illustrated books on trees, oil paintings, watercolours and prints, landscape gardening, poetry, artists' writings. The artists I found most important and/or interesting included the following: Paul Sandby, Thomas Hearne, John Constable, Samuel Palmer, James Ward, John Martin, Edward Lear, Francis Danby, Jacob George Strutt and Henry William Burgess.