Hardy Plant Society

HPS Primrose Study Day 2010

The HPS Western Counties Group held a Primrose and Primula Study Day on 10th April 2010 at Chaddesley Corbett in Worcestershire. The morning consisted of two excellent lectures, one given by Joe Sharman of Monksilver Nurseries, and one by Dr Margaret Webster, holder of the Plant Heritage collection of Primula (floral variants). Following a raffle and lunch, the day concluded with a visit to Olive Mason’s outstanding garden in the village of Chaddesley Corbett, and the traditional tea and cake. A truly enjoyable and illuminating day was had by all, and our thanks go to the hosts and speakers for sharing their knowledge and enthusiasm with all those attending.

We also have some photographs of HPS members visiting Dial Park Gardens as part of the study day.

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Karen Reid on Dr Margaret Webster’s talk to the Primrose Study Day

Dr Margaret Webster holds the National collection of Primula (British Floral variants) and her talk concerned her investigation into the morphology and the subsequent breeding of primula variants which have resulted from her research.

Margaret concentrated on three primulas native to the British Isles: Primula vulgaris, Primula elatior and Primula veris. Margaret discussed their range, habitat and genotype and variations that occur in wild populations of native Primula ssp.

Primula flowers are heteromorphic which means they deviate from the normal and have more than one form of flower. In the case of primula deviations, the most common deviation occurs when individual plants produce either pin-form or thrum-form flowers. This deviation affects the position of the stigma, which in pin-forms, is positioned at the mouth of the flower, while in thrum-forms it is located half way down the corolla. Pin-form and thrum-form flowers are indistinguishable during early development of the flower. The variations occur after the development of the floral organs. Margaret used electron microscopy to observe early development of Primula vulgaris, P. Veris and polyanthus hybrid flowers to define the sequence of early floral development in Primula ssp into specific stages.

She has also studied the development of primula variants, including “Hose in Hose” and “Jack in the Green” from the embryonic stage to maturity and identified the sequence of early floral development. “Hose in Hose” variants of primrose and cowslip have floral organs that are replaced by organs that would not normally occur in that position (homeotic mutants). The sepals are converted to petals and stamens or the sepals and petals do not fuse together to form the calyx and corolla. Primula variants contain homeotic genes which determine which organs form parts of the flower.

Margaret’s breeding work has produced a large number of variants which have been selected for their interest and grown from seed. The variants include double flowers where the reproduction organs are all converted into petals and “Jack-in-the-green” where a green collar to the flower produced by the sepals become leafy. The results of her breeding and selection can been seen at the Primula Society where she regularly exhibits in the Primula shows.

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Jennifer Hewitt on Joe Sharman’s talk to the Primrose Study Day

It can’t be just happy childhood memories of fields of cowslips and primroses that drew 100+ HPS members to the Study Day organised by the Western Counties Group, but affection must have played a part, as well as interest in the native species Primula veris and P. vulgaris, plus the rare true oxlip P. elatior, and their variety of forms and hybrids.

Joe Sharman of Monksilver nurseries has developed a particular interest in these primulas and brought a fascinating, comprehensive display of potted plants, in addition to the illustrations accompanying his talk. He showed that P. vulgaris occurs throughout Europe to Greece and western Asia, but the northern pale yellow colour becomes paler as it goes south and turns to pink and purple in its eastern range. P. veris, the cowslip, also occurs widely and has a number of subspecies.

Unusual forms of both have been found for centuries: “hose-in-hose”, “Jack-in-the-Green”, doubles, feathered calyces, gold- and silver-laced. Hybrids between them also occurred and the polyanthus (Gertrude Jekyll’s “bunch-flowered primroses”) developed and flower size increased. Meetings with other primroses, such as P. vulgaris subsp. sibthorpii, enlarged the colour range by adding red.

Though variations recorded by Gerard onwards may have been lost, they can recur spontaneously. Deliberate hybridising, such as that by Florence Bellis (who developed the “Barnhaven” strains) led to good garden plants, unlike the often short-lived and crudely coloured mass-produced “polys” of today.

Sadly, those fields of our childhood are mostly just memories now, with changes in farming practices, but elsewhere they can still exist, as Joe’s final photos of multi-coloured acres in Turkey showed. And when we looked at his potted plants and remembered his words and pictures, we had learned more about the riches these species have given our gardens.