menarche [NL, fr men- + gk arche beginning -- cf ARCHI] : the initiation of menstruation; the first menstrual period of an individual.
When my lover bleeds, I climb under the sheets, in the tent where the cats sleep, and I breathe in deep -- I suck in her smell, which soaks into my limbs, making them charged and light, full and red, dark w/ night . . . My finger traces slowly, to follow my gaze on her page. "Mazel Tov" it says "Today you are a woman!"