Nature Notes - Primrose by Ian Brand

“Happy Primrose Day”, it’s on the 19th of April, which is the anniversary of the death of Prime Minister Benjamin Disraeli, who died in 1881. The Primrose (Primula vulgaris) was his favourite flower and Queen Victoria would often send him bunches from Windsor or Osborne House on the Isle of Wight. The tradition continues every 19th of April, with a posy of primroses placed in front of his statue in Westminster Abbey and on his grave at Hughenden Manor in Buckinghamshire.

Primroses have been out in our garden since January. So the name is well chosen: ‘prim(e)’ for first, (well one of the first) and ‘rose’, indicative of plants generally, not specifically the rose family, of which it is not a member.

Cross-pollination is the Holy Grail of reproduction, allowing for a greater genetic mix and the Primrose has a couple of canny tricks to encourage this. Both first described by my hero and favourite Victorian, Charles Darwin, in 1862.

Darwin recognised that the primrose has two different types of flower: ‘pin-eyed’ and ‘thrum-eyed’. The two forms look almost identical apart from the position of female stigma and male anthers. In the pin flowers the female stigma is positioned at the top of the corolla or flower tube, with the anthers positioned half way down and out of view. In the “thrum” flowers the position is reversed with the anthers above and the stigma beneath.

Darwin also observed that the pollen was different. Ever inquisitive, he performed a number of experimental crosses, taking pollen from one flower and putting it onto the stigma of another. He found pin-thrum crosses much more successful than pin-pin or thrum-thrum crosses, thus encouraging cross-fertilisation.

Plants frequently hybridise and Primrose is no exception. This is usually with its close relative, Cowslip (Primula veris). If you need to remind yourself what these attractive plants look like, look no further then the roundabouts at either end of the Burley-in-Wharfedale by-pass where the council has kindly added it to the seed mixture. The love child of these two primulas is the false oxlip (Primula x polyantha) having features of both parents. If the name Primula x polyantha sounds familiar, then this is the hybrid that gave rise to the ubiquitous Polyanthus. Personally though, give me the more subtle beauty of the lemon-yellow primrose or golden cowslip any day.