Reading through this old thread, I just noticed that Hester unintentionally misunderstood the Opies. She says there is no connection between the English "May Games" and "Ring Around the Rosie" (which may be true), and that the Opies are therefore perpetuating nonsense when they say there is a connection among Classical deities, roses, and this rhyme, because those don't appear in English "May Games." But the Opies specified "the Continental tradition of May games," which goes back much further than the English May Games Hester studies. Indeed, the Opies seem merely to have meant European May celebrations, which go back to Classical times and do have all the associations the Opies mention.

As to whether they were part of English May Games, Hester knows more than I. But these associations were certainly known in England prior to the "May Games" proper; Chaucer's Legend of Good Women features Classical deities in rose garlands (though daisies are more prominent in the poem) who visit the poet on May Day. They were also certainly known during the heyday of the "May Games"; Thomas Morton's famous May Revels in Quincy, Massachusetts in 1627 combined a maypole, dancing, and a song to classical deities. Morton himself attested that his maypole "was a Trophe erected at first in honor of Maja, the Lady of learning which they [the Puritans] despise...," while Bradford, his detractor, wrote that "Morton became lord of misrule [...] They allso set up a May-pole, drinking and dancing aboute it many days togeather, inviting the Indean women, for their consorts, dancing and frisking togither, (like so many fairies, or furies rather,) and worse practices. As if they had anew revived & celebrated the feasts of ye Roman Goddes Flora, or ye beasly practieses of ye madd Bacchinalians."

Bradford and Morton were both middle-class rural Englishmen, Morton from Devon and Bradford from Yorkshire. The fact that they were fully aware of May Day's connection with flowers, Classical deities, and even fairies, makes it very unlikely, in my mind, that English people at the time were generally unaware of these connections.