Early Large-Flowered Clematis 'Nelly Moser' One of the most popular Clematis ever, 'Nelly Moser' is a deciduous vine which gets covered with a profusion of impressively large star-shaped flowers, up to 8 in. (20 cm), with 8 pink-lilac sepals, each with a carmine stripe that fades in strong sun, and reddish-purple anthers.