The Meconopsis Group

Colour range within Meconopsis flowers

Colour within the blue poppies

There are many blue Meconopsis, although there are several other colours, such as the startling red of M. punicea, the clear yellow of M. integrifolia, the pure white of M. superba and the rich deep maroon of M. tibetica. Amongst the blue species are monocarpic M. prattii and M. aculeata, and more important horticulturally are the big perennial blue poppies, both species and garden hybrids. But even these are not always blue!

Variation in colour in Meconopsis can clearly be seen in these three images of flowers, from three different plants of Meconopsis grandis. These were photographed on the Arunachal Pradesh/Bhutan border, very near to where George Sherriff collected his plants in 1934. On the herbarium sheet for the specimen of M. grandis GS600, collected by Sherriff, there is a pencilled note ‘Young flowers deep purple lilac. Fully open flowers blue tinged purple’.

Part of the reason for the difficulty in stating the colour of the blue precisely is that the flowers frequently show a continuum of variability. This occurs in the spectral range from pure blues to violets to purples. Close inspection reveals that colour variability is due to the petal tissues containing complex mixtures of pigments and that the relative amounts of the different pigments may differ greatly. 

Close up of petal showing  pigmentation. 

Allan Jamieson ©

The blue of the flowers of the big perennial blue poppies can be variable.  Some plants are relatively stable in colour, for example in M. ‘Slieve Donard’ the flowers are almost always consistently sky-blue, although they may be a little darker shade of blue at opening. M. ’Mildred’ is always a pale turquoise blue. 

M. ‘Slieve Donard

M. ’Mildred’

The causes of instability in colour are obscure but evidence for an environmental cause for variation has been frequently observed. For example, in a given year, or in a particular garden, or even a particular part of a given garden, the flowers of a clonal cultivar such as M. ‘Jimmy Bayne’, may be a pure deep blue with very little admixture of purple, or may be decidedly purple. So far it has not been possible to find hard and fast correlations between environmental factors and the colours observed – although speculation abounds and it has definitely been observed that weather, early on in the plant’s growth, can affect the colour of the flowers. 

M. ’Jimmy Bayne’ showing

colour variations.

It is known that plant colours through the range red to blue are produced by a class of pigments called anthocyanins, of which around 300 are known. These pigment compounds are sensitive to many factors such as pH (acidity or alkalinity), light and heat. For example, an average anthocyanin is red in acid, violet in neutral and blue in alkaline solution. It could be possible that micro changes in the pH within the cells of the tissues of the flower petals are responsible for the differences in colours displayed. Scientific investigation is required in order to come to an understanding of flower colour in the big perennial blue poppies. It might be helpful for such an investigation to be aware of the speculations based on observations of Meconopsis enthusiasts about the causes of colour variations. These include the effects of: 

  • Geographical location and average climatic conditions of the area they garden in.
  • The type of soil in the garden, in particular its pH value.
  • Soil and air temperatures on the flower buds during early development, while still below the soil (particularly below freezing temperatures), while the flower stem is lengthening and also air temperature, in particular at the time of bud opening. Soil water content and air humidity might also have an effect. 

M. ‘Ascreavie’

M. ‘Barney’s Blue’ 

M. baileyi

  • M. ’Ascreavie can be described as a mauve-blue. ’M. ‘Barney’s Blue’ is a George Sherriff Group clone which consistently passes through a range of colours from opening deep pink/purple, lightening to a paler shade, before becoming blue. M. baileyi maintains its own individual colour, pale or deep blue or a rich plum of M. baileyi ‘Hensol Violet’.

M. ’Huntfield’ changed

to a very dark maroon/

purple after being kept

in the back of a dark

 

van. 

Situations out with a garden setting have also been observed as affecting the colour of  petals. Transporting plants to shows, in the back of a dark, warm vehicle for a long time, or plants on display in artificial light for many days at a show alters the colour considerably. These changes to the colour does revert back to a blue colour but not back exactly

 

to the original blue of the plant. 

M. ’Huntfield’ growing in

the border showing more

of the true colour of the

 

cultivar.