"In a dress of white linen and ribbons of green ...." - I take that to mean Garland-dancing rather than Morris Dancing as such.

That's another type of ritual English dance in which all the participants carry half-hoops wrapped in ribbons and flowers and that. All women - though there never seems to have been any big issue made about whether there should be Mixed Garland-dancing for some reason.

I have seen a Garland-dance team who were short a member for a dance, so they roped in a hairy-face Morris Dancer. A sight to remember.