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All ratings refer to the UK growing conditions unless otherwise stated. Minimum
temperature ranges (in degrees C) are shown in brackets
AGM plants have been through a rigorous trial and assessment programme. They are:
This plant will provide nectar and pollen for bees and the many other types of pollinating insects.
It is included in an evolving list of plants carefully researched and chosen by RHS experts. Divided into 3 groups these lists, linked below, are maintained by a team of RHS staff and are reviewed annually.
C. palustris is a rhizomatous herbaceous perennial to 50cm, with rounded, rich green leaves and clusters of deep yellow flowers 4cm in width
C. polypetala is a herbaceous perennial, up to 60cm high and 90cm wide, spreading by rooting stems across ground or across water. It has rounded green leaves, the basal leaves up to 10cm across, the stem leaves fewer and smaller, and shining, bright golden yellow flowers, up to 5cm across, from early spring to summer
C. palustris var. alba is a clump-forming perennial to 25cm tall, with glossy, kidney-shaped leaves and single, bowl-shaped flowers with creamy-white petals and yellow stamens in early spring
C. palustris var. palustris is a marginal perennial plant with glossy, dark green foliage and large, buttercup-yellow flowers in early spring. Flowers are larger and earlier than others included in this species
'Plena' is a strong-growing perennial, to 60cm tall, with creeping rhizomes and rounded, deep green leaves. Fully-double, deep yellow flowers, up to 8cm across, are produced on branched, upright stems in spring
Listed in the RHS Plant Finder
This plant is listed in the RHS Plant Finder book. At present our information about this plant is limited to a list of the nurseries that supply it. In time we will be adding more details including a description, growing information, advice and photographs.
Over 70,000 plants and where to buy them
Britain’s best gardening annual, available now from RHS Mail Order and all good bookshops.
Last-listed in the RHS Plant Finder in 2007
Last-listed in the RHS Plant Finder in 2008
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