Thursday, 5 January 2006

Discogyne - Disk On Flower

Meconopsis discigera
Slightly dark image of a flower of M.discigera that has shed it's petals. Meconopsis have a sub-genus called Discogyne. When Sir George Taylor wrote his book and this classification there were just 2 species in the sub-genus. M. torquata and M. discigera (the colour of which caused him confusion).
This is the blue form from Bhutan (but see later on this page) THIS GROUP OF PLANTS DIFFER FROM ALL THE OTHERS which are placed in the sub-genus Eumeconopsis. THEY ARE DISTINGUISED BY A DISC BETWEEN THE HAIRY OVARY(seed pod) and the STYLE (the stem like bit) and the STIGMA at the tip which collects the pollen and allows the pollen tube to grow down through the style to fertilise the embryo seeds in the ovary. Margaret Thorne image
This is the blue form found in Burma. There is some confusion with this species. Taylor split this and M. torquata off in his monograph based on the disc above the ovary through which protrudes the style and stigma into a new sub genera the Discogyne. This was first described by Prain in 1906 as having yellow flowers but in a 1923 publication changed his mind. Taylor described the colour as crimson red, red, purple or pale blue. They were flowered at Edinburgh in 1923 and later BUT they flowered yellow!! Margaret Thorne images of the blue form.
The leaf of the blue Bhutan form. The leaf appears always to be five lobed and thuis should be compared with the yellow form (later images) which has only 3. The yellow form found in Nepal and Sikkim and occasionally flowered in Scottish Gardens - though not easy being subject to winter rot and taking 3 years to flower. NOTE the pale yellow which is so often typical of blue yellow crosses in Meconopsis. Whether in the distant past this arose as a fertile hybrid (maybe with M. integrifolia/pseudointegrifolia) but it would at least expalin the colour since species that have both blue and yellow flowers are unusual (but not unique with a yellow form of M. horridula described in one site). M. florindae is a very rare yellow form of M. lyrata only described by Kingdom Ward from the Tra La. It would certainly help with all these pale yellow forms if they could be analysed with modern DNA techniques to see if there is evidence of a hybrid status sometime in the past.
The leaves of the yellow form flowering in gardens. Note the leaves of this form are 3 lobed compared to the 5 of the blue form but otherwise these two forms are similar in all but colour. There is confusion in the old literature on this species and as you will see I suspect there has been confusion with another recently discovered species. Meconopsis torquata
Plant of Meconopsis torquata collected by a Tibetan guide from a site near Llasa. For a long time this was only the second species in the sub -genus Discogyne. It was first described by Prain in 1906 having beeen discovered by Walton 2 years earlier. It differs from M. discigera in having very short pedicels to the flowers so they cling to the stem, simple strap like leaves and a very short style (but with the characteristic disc (see next image). A unique feature in the genus are hairs on the backs of the petals. It was described as having red flowers but in fact in life it is blue (blue flowers in this genus tend to turn red when pressed as herbarium specimens).
M. torquata
Image of a single capsule from the plant in the prevous image with the flower just over. A dark green disk can be seen above the ribbed spiny seed capsule with the brown ribbed stigma above it and no sign of a style. The red brown structure folded over it is the dead petal BUT CRITICALLY the unique character of hairs on the back of the petal can be seen.
M. torquata
This is the type specimen and is taken from Sir George Taylor's book on the genus Meconopsis published in 1934. The plant is clearly the same as the live collected specimen adjacent. During the second world war both Ludlow and Sherriiff were based in Llasa in an official capacity for the British Goverment and both collected this plant and noted the flowers were a clear blue. It was briefly flowered in cultivation by the great General Murray-Lyon in Perthshire but did not open properly or set seed.
Meconopsis tibetica
Typical of the superb images taken by Harry Jans. Research by John Birks from Norway has shown this plant was found and descibed by Howard-Bury on an Everest expedition in 1921 and specimens were collected. It was not properly recorded (and the specimens not located) until refound in 2005 by Hilary and John Birks and others. Christopher Grey-Wilson identified this plant and produced a formal description of it in the June 2006 Bulletin of the Alpine Garden Society
No Image Available Image on page 109 off "Alpine plants of China" ed. Zhang Jingwei and published in 1982.
Meconopsis simikotensis
Chris Grey-Wilson described this in the Bulletin of the Alpine Gardener 2006. This plant was collected from west Nepal (an area with difficult access at present) by the Stainton, Sykes and Williams expedition of 1952. Presumably photographs of the plant were taken but they cannot currently be located. It occurs at lower altitudes and might be growable if seed is ever collected. It differs rom M. discigera in having unlobed leaves all the way up the stem and a linear as opposed to a capitate stigma. It differs from M. tibetica in having small blue or purple flowers and characters of the stylar disc.
Meconopsis pinnatifolia
There is a reasonable image of this species in the ALPINE PLANTS OF CHINA. With knowledge you can see this plant is in the Discogyne and as M. pinnatifolia is the only species in this sub-genus with pinnatafid (lobed) leaves the identification is straightforward. To my knowledge it has not been in cultivation
M. tibetica
Key image by Margaret Thorne showing unmistakeably the pentagonal red stylar disc and long style above, capped by a capitate stigma. Clearly then in the sub-genus Discogyne. It is distinguished from M. discigera by having unlobed simple leaves, flower colour and the details of the fruiting body
M. manasluensis
This completely new species was found adjacent to the Manaslu Himal in central Nepal. It is so far unique in the sub genus Discogyne on account of the multiple flowering scapes - see next image (all others are racemose). This image is a photograph from Paul Egan's recent paper in Phytotaxa 20:47-56 (2011). It has a very long style and is sympatric (occurs in the same area) with M. pinnatifolia (see above) which is also in the Discogyne. This paper also describes another new species from Nepal - M. autumnalis - a late flowering M. paniculata relative. There are excellent colour images in this paper as well as really beautiful botanical drawings by Sharon Bradley.
M. manasluensis
A whole flowering image from Paul Egan clearly showing scapose nature of this new species. The very long stigma is very well shown in these images.
M. manasluensis
Seed pod showing very long style but particularly the pink disk immediately on top of the ovary (seed pod). This is what puts this species in the sub-genus Discogyne. Until fairly recently there were just two species in the sub-genus now there are six and M. discigera will almost certainly be split into the blue flowered form and the yellow form though hppefully not before a genetic analysis since there is something mysterious about this pair!
Plant dug up to show large root which indicates this monocarpic plant takes some years to flower but more importantly the unique feature of this species in the Discogyne in that the flowers are all scapose not racemose like all the other species. This can be a high altitude feature.