I dont have subsp. Louisae, I only have Hutchinsoniana subsp hutchinsoniana, but the flower and all other features are very close to the picture from the book (white flower). the pink flowered plant does not look like any Hutchinsoniana for to me. More like sheldonii etc, something in that area. For Louise/hutchisoniana look at the pointy wide spread petals and mores the large wide stigma, which is not present in this plant.