Nodding, semi-double lavender-blue flowers. Outer staminodes are the same colour as the flowers, inner staminodes are greenish or white. The variety has received the Royal Horticultural Society's Award of Garden Merit.

It should be noted that this cultivar has a very confused history; catalogues and growers disagree on the true form of the plant and for this reason we have withdrawn a number of our original pictures. Frequently today plants labelled 'Maidwell Hall' are, in fact, 'Lagoon' (ironically Jackman originally named this form macropetala 'Lagoon' before adopting macropetala 'Maidwell Hall' and using macropetala 'Lagoon' for the later selection that bears the name today). The image from Wim Snoeijer is of a plant directly descended from stock of the Jackman nursery. Wim tells us that "the true 'Maidwell Hall' can be recognised by its very regular flower shape and the colour is very evenly blue with very obvious purple staining on the outside especially towards the base."