Hi Ignacio, being these species typical alpine plant species they should grow on acidic soil. As species of the Gentiana genus they prefer acidic soil, but as you can read in the first link below

http://flora.uniud.it/scheda.php?id=1390

G.l. symphyandra is a calciphile plant.

http://eusoils.jrc.ec.europa.eu/library/data/ph/Documents/pH_Pub.pdf

Have a look at the literature to seek for more details.

Hope this helps

Hi Ignacio,

I have studied Gentiana lutea subsp. symphiandra as this is the only taxon that occurs on the territory of Bulgaria.

The populations on Vitosha and Rila Mts grow on silcate. However there are few plants that occur on marble bed rock in Pirin Mts

Hi Ignacio,

here's a paper in Extremadura Gentiana lutea if your interest:

http://centrodeinvestigacionlaorden.gobex.es/HabitarCSS/Pdf/folia%20vol1%20pdf%20web/articulo5p.pdf

The research carried out at natural stands of Yellow Gentian (Gentiana lutea) in the mountains of the Balkans (Serbia and Montenegro), we found that it is most commonly found in the soil with an acid pH soil reaction. Our results were published in following publications (abstracts 1 and 2, are included for your reference):

1. Radanović D., Nešić LJ., Sekulić P., Belić M., Maksimović S., (2005): Physical and chemical characteristics of the soils of some natural sites of yellow gentian in west Serbia, Zemljište i biljka, 54, No. 3, 183 – 192.

Abstract: The following soil types were identified on the mountains Suvobor, Maljen and Povlen, in West Serbia, which are the natural sites of yellow gentian (Gentiana lutea L.): dystric brown soil on the neutral and basic eruptives and eutric siliceous coiluvial deposit (on Maljen) with the lithic contact at the depth of 40 - 70 cm. The soils are more or less skeletal and the fraction of fine soil has a light textural class. In the upper part of the profile, the soils have high total porosity (52 - 67%) and good water permeability (ranging within 10-2 - 10-3 cm/second). The common characteristics of the surface soil on all three mountains are the high percentage of humus (3-8 %), the extremely low percentage of phosphorus (0.4 - 6.4 mg/100 g) and the low to medium percentage of potassium (8.2 - 20.9 mg/100 g). Generally, the reaction of soil pH (H2O) is below 6.5 which is evaluated as favorable for yellow gentian. Due to a high percentage of serpentine in the parent rock, the ratio of exchangeable cations (Ca:Mg = 0.4:1 and K:Mg = 0.02:1) is disturbed. In the soils of Maljen and Suvobor the percentages of Ni (600 - 1900 mg/kg) and Cr (170 - 450 mg/kg) are significantly higher.

In Montenegro (2), in most examined localities, the soil was medium acidic (from 4.80 – 5.22 pH / KCl). The high acid soils were on Bjelasica (Strmenica and Kobilja heads, pH KCl = 4.39 – 4.46) and he Sinjajevina (4.60), and the lowest acidity was on Prošćansko Mountains (average pH / KCl = 5.49). All soils are very rich in humus, with an average content of humus ranging from 5.59 % in Strmenica to 28.21% on Ljubišnja.

2. Balijagić J., Radanović D., Antic Mladenović S., Crnobarac J., Bošković J., Zečević V., Dozet G., Jovančević M. (2012): Mineral content of autochthonous gentian, Gentiana lutea L., root from natural habitats in northern parts of Montenegro. In Dajić – Stevanović Z. and D. Radanović (Eds) Proceedings of the Seventh Conference on Medicinal and Aromatic Plants of Southeast European Countries (Proceedings of the 7th CMAPSEEC), Subotica, May 27th-31st, 2012, pg. 255 – 264.

Abstract: The content of biogenic elements (P, K, Fe, Mn, Zn, Cu, Co) and heavy metals (Ni, Cr, Pb, Cd) contained in yellow gentian root (Gentiana lutea L) has been examined from nine natural habitats on the mountains of Bjelasica (two locations: Strmenica and Kobilja glava), Prošcenske Mountains, Sinjajevina, Ljubišnja, Koritska plateau (two locations: Gutavica and Konjska reka), Durmitor and Štitovo in Montenegro. The root samples were taken in July and August 2009, in five repetitions for each location. Phosphorus was determined spectrophotometrically, and K, Fe, Mn, Zn, Cu, Co, Ni, Cr, Pb, Cd by AAS in a solution after the burning of the sample in an acid mixture (HNO3 + HClO4 + H2SO4). The soil samples were taken at the same time as the root samples. Primary analysis of soil pH, % of humus, and the content of P and K were done by standard methods for soil analysis. Content of pseudo total quantities of Fe, Mn, Zn, Cu, Co, Ni, Cr, Pb, Cd were done by AAS in 80% HNO3. In most localities that were examined, the soil was medium acidic (from 4.80 - 5.22 pH/KCl). The high acid soils are on Bjelasica (Strmenica and Kobilja glava, pH KCl= 4.39 - 4.46) and on Sinjajevina (4.60), and the lowest acidity is on Prošcanske Mountains (average pH/KCl = 5.49). All soils are very rich with humus, with an average content in an interval from 5.59 % in Strmenica to 28.21 % humus on Ljubišnja.

The average content of phosphorus in gentian root was in an interval between 0.13-0.27 %, and potassium 0.34 - 0.46 %. The interval of variation of the average content of Fe in the gentian root is between 241.37 - 503.53 mg kg-1, while the lowest is on Ljubišnja and the highest on Štitovo. The content of Mn in the root is not high (13.27 - 52.17 mg kg-1), although the content in the soil in most locations is very high (703.00 - 1538.00 mg kg-1). Furthermore, the average content of Cu (4.25 - 10.72 mg kg-1) and Co (0.35 - 0.65 mg kg-1) in the gentian root was relatively low and it is similar with the content of Cu and Co in the soil. The average content of Zn in the root was several times higher (125.57 mg kg-1) on Durmitor than in other localities (17.00 - 34.20 mg kg-1), which could not be related to the content of Zn in the soil. The content of Cr in the root (0.40 - 2.00 mg kg-1) and Pb (1.16 - 2.95 mg kg-1) was in all localities lower than MPC. The content of Ni in the root compared to other localities was highest in the locality of Kobilja glava (7.62 mg kg-1) as well as the content of Ni in the soil (78.5 mg kg-1). In other localities the level of Ni in the root was lower than MPC (1.5 - 4.1 mg kg-1). High content of Cd was found in gentian root from Prošcanske Mountains and Sinjajevina (0.55 and 0.35 mg kg-1) and the lowest ones were in Gutavica and Konjska rijeka (0.07 and 0.06 mg kg-1). Highest content of Cd in soil was also on Prošcanske Mountains and Sinjajevina (0.55 and 0.35 mg kg-1) and the lowest in Gutavica and Konjska rijeka (0.07 and 0.06 mg kg-1).

Dear Ignacio,

for Austria, Liechtenstein and South Tyrol (with subsp. lutea and subsp. vardjanii; cf. http://www.xflora.info/) G. l. is primarily cited for calcareous habitats, but I'm unfortunately not aware of literature dealing with soil reaction and soil characteristics s. str..

PS: the original text from http://www.xflora.info/ is, e.g., also stated here: http://flora.nhm-wien.ac.at/Seiten-Arten/Gentiana-lutea-lutea.htm & http://flora.nhm-wien.ac.at/Seiten-Arten/Gentiana-lutea-vardjanii.htm

Best regards, Chr.