Page 258. " "Amanita caesaria," he said. "Not what you think," he added when he saw the look on my face. "
Amanita caesura, an edible mushroom
Creative Commons Attribution Share AlikeAmanita caesura, an edible mushroom - Credit: Archenzo
Amanita phalloides, a poisonous mushroom
Creative Commons Attribution Share AlikeAmanita phalloides, a poisonous mushroom - Credit: Archenzo

 Amanita caesaria is an edible mushroom, considered to be the favourite of the Roman emperors (hence its name). However, as Henry goes on to say, it resembles the highly poisonous Amanita phalloides, and is therefore not a popular choice among modern mushroom pickers.

Amanita phalloides has been implicated in the deaths of the Roman Emperor Claudius and  Holy Roman Emperor Charles VI.

Page 268. " This was, in fact, the basis of his acquaintance with most of the famous people in his life. "

All of Julian's famous friends mentioned here tend to be English or American writers and who were prominent in the early or mid-twentieth century. It is particularly interesting that Tartt connects Julian with Harold Acton (1904-1994) as it creates an oblique reference to Brideshead Revisited by Evelyn Waugh and The Waste Land by T.S. Eliot. Acton was at Oxford with Evelyn Waugh. Although Waugh stated that Acton was not the primary inspiration for his character Anthony Blanche, he did inspire one particularly memorable scene in Brideshead when he proclaimed The Waste Land through a megaphone from a balcony. Brideshead is never directly mentioned in The Secret History, and yet the latter was clearly influenced by it.

Brideshead Revisited on Book Drum

Page 268. " Sara Murphy, no mean hostess herself, once wrote him pleading for his recipe for sole véronique "
Portrait of Sara Murphy by Picasso
Public DomainPortrait of Sara Murphy by Picasso
 Sara Murphy and her husband Gerald were expatriate American socialites, famous for their parties on the French Riviera in the 1920s. Dick and Nicole Driver in F. Scott Fitzgerald's Tender is the Night are thought to be based on the Murphies. Picasso, who was a friend, painted Sara Murphy several times.

Sole véronique is a famous French fish recipe that marries dover or lemon sole with tarragon, cream and grapes. See here for Delia Smith's version.