S. x luteo-purpurea (SS. aretioides x media)
Although this interesting Pyrenean hybrid was first discovered and described by the French botanist Lapeyrouse in 1801, and written about by Walter Irving in the Gardeners Chronicle in May 1908, it was not until 1915 that real interest took hold. In that year Franz Sundermann described (partially) eleven distinct forms of S. x luteopurpurea in Allgemeine Botanische Zeitschrift. Two of these were used by Farrer and Russell Prichard to produce two outstanding cultivars, namely 'Myra' and 'Cranbourne', another recent introduction, S. lilacina, being the other parent.
Botanists have a name for these natural hybrids like S. x luteopurpurea; they call them notomorphs (nm), which means a population of hybrids that has stabilised through self-crossing. In 1919, Engler & Irmscher put all eleven plants into three named groups:
1. S. x benthamii
Close to S. aretioides.
nm. grandiflora, nm.parviflora, nm. aurantiaca, nm. flavescens;
2. S. x luteo-purpurea
Intermediate between the parents.
nm. luteo-purpurea, nm. erubescens, nm. lapeyrousii;
3. S. x ambigua
Close to S. media.
nm. ambigua, nm. racemiflora, nm. grenied, nm. godronia.
Although it is technically incorrect to group them this way now, it is a practical method for listing them.
Since the Second World War, only one of these plants has survived in cultivation as far as we know, namely nm. aurantiaca, although many imposters have paraded under their names.
Herr Sundermann found his plants in the French central Pyrenees at a quarry near St. Beat, in the Haut Garonne. Several dedicated plantsmen have searched the area in the last few years looking for Sundermann's lost children, but with no success. It is possible that the original site is now an extended marble quarry, or has become overgrown with scrub; but I cannot help feeling that a more extensive search may well find them.
Phillipe Lapeyrouse discovered his plants further east in the Ariege near Saleix. In 1989, Henry Taylor visited the area under strict instructions to keep an eye out for them: he returned home with some cuttings of S. x luteo-purpurea. The following year Brian Arundel and I explored this little known backwater and found many hybrid plants.
S. aretioides is very common in this area and there are several stations of S. media, particularly at the higher altitudes, although it is nowhere near as common here as S. aretioides. Where the two species grow together in good numbers there were usually several hybrids to be seen. We collected some cuttings from a selection of the hybrids, these have since grown into good size plants and have flowered twice.
Three distinct forms have been found, they are numbered AA12, AA7 and SA17. Two are intermediate between the species and one very close to S. aretioides. One of the intermediate forms, AA12, is by far the most common. It is proving difficult to match them precisely with Sundermann's forms: AA12 is closest to nm. luteo-purpurea, AA7 to nm. lapeyrousii and SA17 to nm. grandiflora.
S. x luteo-purpurea AA12 coll. Saleix, June 1990, A Young.
Firm domed cushion, glaucous green, closer to S. media, rosettes up to 16mm dia. and open; leaves linear, sharply pointed, 11 x 2 mm wide, 15-16 lime pits; flower stem 75mm, green at base, then pink, with red glandular cilia, 13 stem leaves, mainly clasping; inflorescence, cyme with 1-2-3 fls. on 10-15mm pedicels, 5-15 per stem; nodding at first; corolla vase shaped, up to 1Omm dia.; petals orange when first open quickly fading to mid yellow; sepals, pink, then fading. Differs from S. aretioides with larger rosettes and a branched tall flower stem, from S. media with larger orange/yellow petals.
S. x luteo-purpurea AA7 coll. Saleix, June 1990, A Young.
Compact domed cushion, pale glaucous green, intermediate between the species; rosettes 6-llmm dia. and open; leaves 4-6 x 2mm wide, linear, mucronate, 6-8 lime pits; flower stem 65 mm, green with pink pedicels, upright; corolla vase-shaped, 1Omm dia.; petals bright yellow; sepals green. Differs from S. aretioides with taller branched flower stem, from S. media with larger yellow petals.
S. x luteo-purpurea SA17 coll. Saleix, June 1990, A Young.
Firm slightly domed cushion, glaucous green, closer to S. aretioides; rosettes 8-12 mm dia. open; leaves 7 x 2mm wide, linear; flower stem 30-40mm with red glandular cilia, 7 semi patent red or green stem leaves; inflorescence, cyme with 4-7 fls. on 5-10mm pedicels, upright; corolla cup shaped, 16mm dia.; petals 7 x 6mm wide, roundly obovate, bright deep yellow, overlapping; sepals red or green. Differs from S. aretioides with rounder petals giving a fuller corolla, darker yellow petals, from S. mediawith yellow petals, shorter flower stems.
It is more than likely that other forms of this hybrid still exist in the Pyrenees: I certainly intend to return, when the right circumstances prevail, and carry out a thorough survey. It would be nice to find nm. erubescens; described in the September 1913 edition of the Gardeners Chronicle, with coppery-red flowers. There is also a reasonable photograph taken by Walter Irving.
Self set seed of nm. aurantiaca has produced identical offspring. It will be interesting to see if the other notomorphs breed true. There are possibilities of recreating some of the old hybrids, 'Myra' for example. The newly described notomorphs provide welcome and vigorous new plants which will prove of great interest.
Don, D. 'A monograph of the genus Saxifraga', Transactions of the Linnean Society of London, XIII, p.397 (1821)
Sundermann, F. Saxifraga aretioides x media G. Benth. et Walk., Allgemeine Botanische Zeitschdft, XXI, p. 22-24 (1915)
Irving, W. 'New hybrid Saxifragas', Gardeners Chronicle XLIII, p.277 (1908)
Irving, W. 'Saxifraga x ambigua, (nm. erubescens SUND.)', Gardeners Chronicle LIV, p. 183, fig 68 (1913)
Engler, A. & Irmscher, E. 'Saxifraga, Das Pflanzenreich, p.600-602 (1916-19)
Homy, R., Webr, K.M. & Byam-Grounds, J. Porophyllum Saxifrages, p.114-7 (1986)