Wilf and All,
Crosses of standard daffodils with N. tazetta patulus are possible, but I found till now only Ufo, Loch Coire and Actaea to produce some seeds. An extraordinary high number of these seedlings has fertile pollen. This spring I found 6 fertile plants from perhaps 30 flowering seedlings of Actaea x N. tazetta patulus and 4 fertile plants from perhaps 20 flowering plants of Loch Coire x N. tazetta patulus. 8 flowers have pollen of the form NT, the pollen of one flower is unreduced ( NNT) and one has 4 times the volume of the NT-pollen . To conclude that it is NNNNTTTT is probably not the truth. The plants with the pollen NT can be crossed with Matador(NNTT) and its fertile relatives like Bright Spangles and some others to get more fertile plants with NNTT.
For the old and very nice Geranium (NT) I found many fertile unreduced NT pollen. It can be used in the same way for crosses as the NT pollen above.
Theo