Until the beginning of the 1970s the area on the Science Site around the Library and the Calman Learning Centre was the university botanic garden, adjacent to the Botany Department which was located in the Dawson Building. The primroses that you can find flowering in April alongside the hedge that flanks South Road are a legacy of the old botanic garden and of the research of the late Dr. Jack L. Crosby, Reader in Genetics, who was a notable authority on the genetics of Primula , an expert on plant population genetics and was one of the first to use computers in this branch of plant sciences.
Most of the plants along the hedge are either primroses (Primula vulgaris) or hybrids between those and cowslips (P. veris), which are known as false oxlips Primula veris x vulgaris. True oxlip (P.elatior) is a rare species confined to a diminishing number of woodland locations in the east midlands but false oxlips tend to occur wherever primroses and cowslips grow side-by-side. Where the species overlap plants with every combination of intermediate characters are produced, by a process known as introgression.
There are also some magenta primula species of unknown origin amongst the false oxlips and from time to time this species also hybridises with the false oxlips, producing pink-flowered plants. This exactly mimicks the way in which the garden polyanthus, with its wide range of flower colours, arose.
I have a lot of oxlip looking plants in my yard when I moved into the house 7 years ago. It seems that they are extremely drought tolerant. I moved them around so they are lined up in the front of different borders. With that, that means I will notice any new volunteers easily. In the first 2 years, I only saw creamy yellow flowers. 3 years ago, I saw one with soft pink. I marked that plant and it continues to have soft pink flowers every spring. This year, I saw a soft salmon color. How did that happen?
ReplyDeleteApologies for the slow reply. The oxlip-looking plants are most likely primrose x cowslip hybrids (the ancestor of the cultivated garden polyanthus) and the pink and salmon coloured individuals are most likely further crosses between these and cultivated polyanthus or primroses that have, at some point in their past, been cross-pollinated by a bee carrying pollen from another compatible Primula species with these flower colour genes - see http://cabinetofcuriosities-greenfingers.blogspot.co.uk/2012/05/primslips-and-cowroses.html for some more examples.
ReplyDeleteOne source of these flower colour genes is thought to be a form of the common primrose called Primula vulgaris subspecies sibthorpii, which has flower colours that range from pink to purple. It grows naturally in the Balkans and south-west ASia but has been cultivated here for centuries. Best wishes, Phil Gates