The Dutch National Plant Collections are part of the Dutch Botanic Gardens Federation and their goal is to create a 'National Plant Collection' held cooperatively through the botanic gardens. They therefore try to avoid duplication of collections. http://www.botanischetuinen.nl/SNP-2.html
The Nederlandse Planten Collecties are by contrast held almost exclusively by commercial nurseries as reference collections. They have been in existence since 1995 and have around 100 collections. They are an initiative of the Koningklijke Vereniging van Boskoopse Culturen (KVBC) the Dutch Royal Horticultural Society.
Bearded Irises and some beardless at http://plantencollecties.nl/Iris/1564
-- BobPries - 2013-12-03