From the eldritchdark site, which has links to all the stories, poems, etc.:
Cycles of Clark Ashton SmithClark Ashton Smith's work can be divided in to a number of cycles: Averoigne, Hyperborea, Mars, Poseidonis, Xiccarph, Zothique Each of which represent a shared world or theme Creating for Smith the desired backdrop in to which to explore his fantasies Below is a list of works contained within each cycle and some brief notes on the cycle
As well as theses Smith classified cycles, one can break his work in to a number of other categories such as those works that can be considered part of the Cthulhu Mythos
AveroigneThe Averoigne stories are based in a relatively mundane (for Smith) province in medieval France This backdrop provides a platform for Smith to explore several 'non-fantastic' areas that the rest of his work does not Many all to human junxpositions are exploded uniquely in this cycle, such as: Animal and man; religion and science; the divine and the mortal
Description-Location: 'region in France, heavily forested — located somewhere between Tours and Moulins; a "main highway" between those two cities goes through it (The End of the Story, Clark Ashton Smith)
* Beast of Averoigne, The (1933)
* Colossus of Ylourgne, The (1933)
* Disinterment of Venus, The (1934)
* Enchantress of Sylaire, The (1941)
* End of the Story, The (1930)
* Holiness of Azédarc, The (1933)
* Maker of Gargoyles, The (1932)
* Mandrakes, The (1933)
* Mother of Toads (1934)
* Rendezvous in Averoigne, A (1931)
* Satyr, The (1931) [Variant Conclusion to "The Satyr"]
HyperboreaThe Hyperborean tales represent Smith's greatest contribution to the Cthulhu Mythos but with a harder edge than Lovecraft's work They span a chaotic world where non-anthropomorphic Tsathoggua still dwells and large flesh eating worms bring icy oblivion
Description-Location: "supposed to have corresponded roughly with modern Greenland, which had formerly been joined as a peninsula to the main continent" — in Miocene times ("Ubbo-Sathla", Clark Ashton Smith)
* Coming of the White Worm, The (1941)
* Door to Saturn, The (1932)
* House of Haon-Dor, The (1989)
* Ice-Demon, The (1933)
* Lament for Vixeela (1953)
* Muse of Hyperborea, The (1929)
* Seven Geases, The (1934)
* Tale of Satampra Zeiros, The (1931)
* Testament of Athammaus, The (1932)
* Theft of the Thirty-Nine Girdles, The (1958)
* Ubbo-Sathla (1933)
* Weird of Avoosl Wuthoqquan, The (1932)
* White Sybil, The (1932)
MarsClark Ashton smith wrote five (four by himself one of which was a fragment and one with a plot provided by E M Johnson) stories that are based on Mars Unlike his contemporaries, Mars is not a place of Green Bug-eyed Martians set to invade the earth (see below), rather, a backdrop similar to Zothique Mars is described in all but Vulthoom (Vulthoom is set in the commercial metropolis of Mars - Igarth, with its 'old quarter' being much like Lovecraft's Dunwich) as a hash arid world possibly near its end It is used as a stage in which to 'drop' unwitting earthlings Once with in the alien situation our lead characters show typical human emotions of exploitative zeal usually followed by fear and loathing
While The Vaults of Yoh-Vombis and The Dweller in the Gulf would of been equally effective stories had they been set on earth Seedling of Mars and Vulthoom utilised the 'alien invasion' motif popular in the pulps at the time However, theses did not contain your typical alien invasion scenarios Vulthoom was an alien 'god' (plant like) who came to mars when humans "were still the blood-brothers of the ape," and now wishes to move to Earth Vulthoom's plot is only temporarily foiled by being put back to sleep for a thousand years The plant thing in Seedling of Mars has better luck in that it does get to take over the earth
* Dweller in the Gulf, The (1933)
* Mnemoka (1955) Fragment
* Vaults of Yoh-Vombis, The (1931)
* Vulthoom (1935)
* Seedling of Mars or The Planet Entity [plot by - E M Johnson] (1931)[An alternative background to the proceeding 4 stories]
PoseidonisIt was Plato that Greek philosopher who first dreamed Atlantis but I'm sure his dreams where not as weird as Smith's Poseidonis is "the last isle of foundering Atlantis" One common theme can found is this short cycle that is, every thing comes to an end, and the end usually is not a pleasant one
Description-Location: "a large isle", "the last isle of foundering Atlantis" — "with its opulent seaports, its eon-surviving monuments of art and architecture, its fertile inland valleys, and mountains lifting their spires of snow above semi-tropic jungles" — "mountains of the interior" — people thought of themselves as Atlanteans — "members of an aboriginal race of Atlantis" survived on Poseidonis as slaves ("A Voyage to Sfanomoe", Clark Ashton Smith)
* Atlantis (1912)
* Death of Malygris, The (1933)
* Double Shadow, The (1933)
* Last Incantation, The (1930)
* Muse of Atlantis, The (1922)
* Tolometh (1958)
* Vintage from Atlantis, A (1933)
* Voyage to Sfanomoe, A (1931)
XiccarphOne of the smallest cycles but an interesting one In both stories the all powerful sorcerer Maal Dweb tries to stem his boredom by playing with lesser beings However, in the end he returns to his sullen ennui
Description-Location: "planet — has "four diminutive moons" [because of their size or because each is "decrescent"?] — "the juice of a jungle plant [is] repugnant to all the fauna of Xiccarph" — chimera-skin used as leather — has reptiles, dragons, pterodactyls, chimeras, poisonous "winged vipers", ape-like creatures — three suns, all dawn in the east, set in west: the earliest sun is "gamboge-yellow", second is emerald, third is carmine" ("The Maze of Maal Dweb", Clark Ashton Smith)
* Flower-Women, The (1935)
* Maze of Maal Dweb, The (1938)
ZothiqueThe Largest of Smith's cycle and lying in the far future as opposed to Hyperboreas distance past It consumed most of his writing time during the 30's although he continued to add to his Hyperborea and Averoigne cycles The Last Hieroglyph was not only his last Zothique tale it was also his last story for a considerable amount of time
Description-Location: "inhabited isles far to the east — continent — many think "madness is a sacred thing" and give hospitality to crazed wanderers — probably in the southern hemisphere" ("Xeethra", Clark Ashton Smith)
* Black Abbot of Puthuum, The (1936)
* Charnel God, The (1934)
* Dark Eidolon, The (1935)Dead will Cuckold You, The (1950)
* Death of Ilalotha, The (1937)
* Empire of the Necromancers, The (1932)
* Garden of Adompha, The (1938)
* In the Book of Vergama (1934)
* Isle of the Torturers, The (1933)
* Last Hieroglyph, The (1935)
* Mandor's Enemy (1989)
* Master of the Crabs, The (1948)
* Morthylla (1953)
* Necromancy in Naat (1937)
* Shapes of Adamant (1935)
* Tomb-Spawn, The (1934)
* Voyage of King Euvoran, The (1931)
* Weaver in the Vault, The (1934)
* Witchcraft of Ulua, The (1934)
* Xeethra (1934
* Zothique (1951)