Nigella hispanica

The Spanish one, and a considerably bigger plant than the Miss Jekyll types. Open star-shaped flowers in deep royal violet-blue with a cluster of prominent burgundy stamens at the centre, on stronger stems up to 75cm.

The single open form is what separates it. Where a Miss Jekyll flower is a soft semi-double half hidden in its ruff of foliage, this one is flat, dark and frankly showy, and the burgundy centre does a lot of work. For cutting it is the more useful nigella of the two, with longer, thicker stems that hold up in an arrangement.

The seed pods are the other reason to grow it. They are large and green and topped with spreading horns like a jester's cap, and they stand in the border into autumn and dry very well.

It flowers a little later than Nigella damascena, so growing both extends the season. Direct sow only, since the taproot resents moving, and September sowing gives the strongest plants. Keep it lean, cut it often to push out side shoots, and expect it to seed itself about generously.