In The Song of the Lark, Thea mentions having once stolen a sachet of orris-root powder. It's a similar idea, I think. Fred laughs and says that her things always smell of orris. Thea explains that she has gone back repeatedly to the store to buy it ever since to make it up to them. The fact that Fred knows what her linens or (more likely) undergarments smell like suggests their physical intimacy. Doing a Google book search, I see that the sachets with the scent of "new mown hay" use orris-root powder in their blend (as do other scents). I wonder if this choice suggests Thea's connection to the American landscape. I wonder what scent of sachet Willa Cather herself used.