The New Encyclopedia of Hostas (2009) by Diana Grenfell and Michael Shadrack along with other sources list the following hostas as having especially attractive and/or interesting flowers.

 
CultivarsPlant SizeLeaf ColorVariegationVar ColorOriginFlower ColorSeasonSourceRegistered
'Academy Flora'MediumMed-Green--UnknownPale-LavenderJulyChamberlain, Steve.1999
'Aphrodite'LargeMed-Green--Nat-SportPure-WhiteAugust to OctoberMaekawa, Dr Fumio, Schmid, W. & Walek, Kevin.2009
'Aureomaculata', H ventricosaMediumYellowMarginalDark GreenNat-SportLight-PurpleJulyAHS.1987
'Austin Dickinson'MediumMed-GreenMarginalYellowHybridLight-PurpleAugust to OctoberLachman, Wm & Eleanor.1992
'Blackberry Tart'MiniatureMed-GreenMarginalWhiteUnknownDeep-PurpleJuly into AugustLydell, Ransom--NR--
'Blue Angel'GiantBlue/Green--UnknownPure-White-Shaw, Florence.1986
'Elegans'GiantBlue/Green--UnknownPale-LavenderJune into JulyArends, George & AHS.1987
'Fujibotan'MediumMed-Green--UnknownLight-PurpleJuly into AugustWatanabe, Kenji--NR--
'Gold Regal'GiantYellow--HybridMed-LavenderJulyAden, Paul & Unknown.1974
'Guacamole'LargeLight-Green--Nat-SportPale-LavenderAugust to OctoberSolberg, Robert.1994
H. laevigataMediumDark-Green--UnknownLight-PurpleAugust to OctoberSpecies from Korea--NR--
H. plantagineaLargeMed-Green--UnknownPure-WhiteAugust to OctoberSpecies from China--NR--
H. ventricosaLargeDark-Green--UnknownLight-PurpleJulySpecies from China--NR--
'Krossa Regal'GiantBlue/Green--UnknownPale-LavenderJuly into AugustKrossa, Gus & Summers, Alex.1980
'Lakeside Whispering Leaves'GiantBlue/Green--HybridMed-LavenderJuneChastain, Mary.2005
'Matthew J. Walton'LargeDark-Green--HybridLight-PurpleJuly into AugustChamberlain, Steve.2001
'Midwest Majesty'GiantYellow--Nat-SportMed-LavenderJulyMinks, Eldren.1983
'Mira'GiantBlue/Green--Nat-SportPale-LavenderJune into JulyMaekawa, Dr Fumio & AHS.2002 .2018
'Nakaimo'LargeMed-Green--HybridMed-LavenderJulyImperial Botanic Garden Tokyo & AHS.1986
'Rubies'-Med-Green--Unknown--Lydell, Ransom--NR--
'White Fairy'LargeMed-Green--Nat-SportPure-WhiteAugust to OctoberUnknown--NR--
'Yoshie'LargeMed-Green--UnknownLight-PurpleAugustBenedict, Dr R. (Herb) & Kuenster, Rod.2010
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