RS Gwynn (on Imaginary Books, mon, 28 Mar 2016) wrote: “Tough to beat "The Combed Clap of Thunder" or "The Plaster Cramp." I guess Nabokov's best imaginary titles are in The Real Life of Sebastian Knight, but I don't have the book to hand to check. / Sam.”
Jansy Mello: It just occurred to me that Nabokov’s “imaginary titles” appear under different guises and serve various ends. In ADA, for example, I came across two modified titles for “real” books”, mostly a play with sounds. Nevertheless, one of its character’s (Mlle Larivičre) writings constituted the kind of “imaginary books” mentioned in the article found in The Paris Review (fwd by S.Blackwell to the List). Sebastian’s titles and those in LATH are playful disguises for self-referential parodies.
Examples: 1. .... ‘That tattered chapbook must also belong to her, Les Amours du Docteur Mertvago, a mystical romance by a pastor.’/
‘Playing croquet with you,’ said Van, ‘should be rather like using flamingoes and hedgehogs.’ /
‘Our reading lists do not match,’ replied Ada. ‘That Palace in Wonderland was to me the kind of book everybody so often promised me I would adore, that I developed an insurmountable prejudice toward it. Have you read any of Mlle Larivičre’s stories? Well, you will. ADA 1,8
Cf. AdaOnline 53.22-24: ...Darkbloom: “Les amours du Dr. Mertvago: play on ‘Zhivago’ (zhiv means in Russian ‘alive’ and mertv, ‘dead’).” “Pastor” is a pun on Boris Pasternak (1890-1960), who published Doctor Zhivago in 1957, and on what Nabokov thought the book’s “sickly sweet brand of Christianism” (SO 206)
53.25-28... Nabokov translated Alice’s Adventures in Wonderland into Russian in 1922 (published as Anya v strane chudes, 1923)./ Cf. 129.17: “ Ada in Wonderland”; 568.06: “ Ada’s adventures in Adaland.”
2. ...Had a grotesque governess really written a novel entitled Les Enfants Maudits? To be filmed by frivolous dummies, now discussing its adaptation? ADA 1,32
Cf.AdaOnline 198.26-29: ...Les Enfants Maudits seems to owe less to Maupassant (see 197.01 and n.) than to Chateaubriand’s René (see 3.08n., 199.05-6, 201.05-08), to the action unfolding at Ardis, and to the novel Les Enfants Terribles (1929), by Jean Cocteau (1889-1963), which Cocteau adapted for a movie version of the same name (1950) directed by Jean-Pierre Melville (1917-1973). Cocteau’s story focuses on two teenagers, sixteen-year-old Elisabeth and her fourteen-year-old brother, Paul, whom she loves with an exclusive passion. They retreat from the outer world into the imaginative hothouse of their Room, but their friendships with others, Gérard, Michael and Agatha, shatter their enclosed world...
On another subject, now related again to “stink bombs”:
I was wondering if VN could be making a convoluted allusion to the Maidenhair or the Gingko Biloba tree ( although he only indicates two tulip trees), whose dropping seeds have a particularly foul smell and which plays such a significant role in “Ada or Ardor”:
Tulip tree: two-lip tree and Bi-loba: two lobes (later, “flat-lying couple”) 
(Getty images)
“The species was initially described by Carl_Linnaeus in 1771, the name biloba derived from the Latin bis, "two" and loba, "lobed", referring to the shape of the leaves. Two names for the species recognise the botanist Richard_Salisbury, a placement by Nelson as Pterophyllus salisburiensis and the earlier Salisburia adiantifolia proposed by James_Edward_Smith. The epithet of the latter may have been intended to denote a characteristic resembling Adiantum, the genus of maidenhair ferns.https:// https://en.wikipedia.org/wiki/Ginkgo_biloba#Taxonomy_and_naming. [ ] The old popular name "maidenhair tree" is because the leaves resemble some of the pinnae of the maidenhair fern Adiantum_capillus-veneris.).”
“They’ve been called ‘vomit trees,’ dropping seeds referred to as ‘poo berries’ and ‘stink bombs.’ They emit an odor commonly described as smelling like sour milk, old cheese, rancid butter, and dog poop [ ] Most cities pick the non-flowering male trees for landscaping to prevent the smelly fruits from stinking up the sidewalks./And, indeed, those male trees were planted here. But something happened between planting and now: They changed genders./“If some trees are under stress, like the drought last year, or like being inside an urban area with the pollution and everything, the males shift and develop female ovaries and switch sexes to ensure their survival,” George Pinkerton, director of maintenance for the Downtown Lincoln Association said. “It was never the intention to plant female trees down there.”/This gender shift is a pretty rare phenomenon.” http://www.newsnetnebraska.org/2013/04/03/spring-here-watch-out-for-ginkgo-stink-bombs/
Quotes from ADA related to gingko biloba, a folio found in the attic, Ada’s ‘infolio’/adiantofolia, a flat-lying couple on Atticus paper (similar to the leaf of the gingko tree, see illustration above and underlined parts below).
The specimens were on one side of the folio, with Marina Dourmanoff (sic)’s notes en regard.//
Ancolie Bleue des Alpes, Ex en Valais, i.IX.69. From Englishman in hotel. ‘Alpine Columbine, color of your eyes.’
Epervičre auricule. 25.X.69, Ex, ex Dr Lapiner’s walled alpine garden.
Golden [ginkgo] leaf: fallen out of a book’ The Truth about Terra’ which Aqua gave me before going back to her Home. 14.XII.69. (ADA 1,1)
(Torture, my poor love! Torture! Yes! But it’s all sunk and dead. Ada’s late note.) / The three of them formed a pretty Arcadian combination as they dropped on the turf under the great weeping cedar, whose aberrant limbs extended an oriental canopy (propped up here and there by crutches made of its own flesh like this book) above two black and one golden-red head as they had above you and me on dark warm nights when we were reckless, happy children. (1,32)
204.17-19: cedar, whose aberrant limbs extended an oriental canopy (propped up here and there by crutches made of its own flesh like this book): Cf. 587.34-88.04, Van and Ada’s final manuscript of Ada: “the master copy which the flat pale parents of the future Babes, in the brown-leaf Woods, a little book in the Ardis Hall nursery, could no longer prop up in the mysterious first picture: two people in one bed.”
Cf. “flat-lying couple/ Atticus paper” quote, below.
Maidenhair. Thus named because of the huge spreading Chinese tree at the end of the platform. Once, vaguely, confused with the Venus’-hair fern. She walked to the end of the platform in Tolstoy’s novel. First exponent of the inner monologue, later exploited by the French and the Irish. N’est vert, n’est vert, n’est vert. L’arbre aux quarante écus d’or, at least in the fall. Never, never shall I hear again her ‘botanical’ voice fall at biloba, ‘sorry, my Latin is showing.’ Ginkgo, gingko, ink, inkog. Known also as Salisbury’s adiantofolia, Ada’s infolio, poor Salisburia: sunk; poor Stream of Consciousness, marée noire by now. Who wants Ardis Hall! (1,41)
What everybody thought would be Violet’s supreme achievement, ideally clean, produced on special Atticus paper in a special cursive type (the glorified version of Van’s hand), with the master copy bound in purple calf for Van’s ninety-seventh birthday, had been immediately blotted out by a regular inferno of alterations in red ink and blue pencil. One can even surmise that if our time-racked, flat-lying couple ever intended to die they would die, as it were, into the finished book, into Eden or Hades, into the prose of the book or the poetry of its blurb. (5,6)