Justification
This is one of the most famous Greek endemics, growing only on Mount Olympus. It is a relict of a mainly tropical family, represented only by two more species in Greece. The taxon is included in the Presidential Decree 67/1981 of the Hellenic Republic, as well as in the Council Directive 92/43/EEC of May 21st 1992, on the conservation of natural habitats and of wild fauna and flora, in Annex IV, as a species requiring strict protection. The location of the species mainly inside Olympus National Park offers it protection from most human activities. Also, the species has a favourable population, thus it is classified as Least Concern.
Geographic Range Information
Ramonda heldreichii, previously known as Jankaea heldreichii or Jancaea heldreichii is a very rare Greek endemic, found only on Mount Olympus. This plant is endemic to north-central Greece, where it only occurs on Mt Olympos, mainly on the north side e.g. Xerolakki Rema, Papa Rema and also on the east side at Enipefs valley from below Agios Dionysios monastery (Delipetrou 2011). It is often described as a "living fossil", because it is a Tertiary relict and one of the five surviving European members of an otherwise tropical (and subtropical) family, the Gesneriaceae, which consists of about 1,100 species. In this family, many “resurrection” species have arisen: plants with the ability to withstand long periods of time with very little water content and successfully revive upon water availability (Legardón and García-Plazaola 2023).
Population Information
Most of the population occur within Mt Olympus National Park (Strid 1995). In a study by Vokou et al. (1990), it was found that its density varies: 25-50 rosettes per m2 were often encountered, but there were also extremes of 100 rosettes per m2, as well as the sporadic appearance of individual plants. Further investigation has to be done on the species' population. It is also stated that this rare endemic plant was not endangered at the time, its population size being adequate to secure survival of the species.
Habitat and Ecology Information
The species is found in damp, shaded crevices of limestone rocks, especially near permanent or semi-permanent streams in the beechforest zone, generally between c. 700 and 1,400 m, mainly on the east and north sides of the mountain (Vokou et al. 1990, Phitos et al. 1995). It is most abundant between 600 and 800 m. R. heldreichii characteristically grows on the north and rarely on the eastern sides of rocks (Vokou et al. 1990). According to the same study, it is an insect-pollinated plant, but no particular relationship between it and its insect partners seems to have evolved. Taking into account the scarce visits of these pollinators to R. heldreichii, and the population sizes of both the plant and its pollinators, it could be argued that the nutritional requirements of these insects could not be satisfied by this plant alone. Nectar, an indispensable element of bumblebees' diet and absent in R.heldreichii, is offered by other plant species, and particularly by Geranium macrorrhizum L., a very well-represented species occurring in almost all the range of R.heldreichii on Mt Olympus. It is noteworthy that all three pollinators of R.heldreichii were also captured while visiting G. macrorrhizum, and the frequency of their visits was far higher. Another point of interest is that the blossoms of R.heldreichii closely resemble in both colour and size, those of many Campanula spp., which are well distributed on Mt Olympus. Additionally, their major areas of occurrence (ravines) are the same. Some of the main pollinators of Campanulae are bumblebees. It could be argued, therefore, that this similarity might lead to visual attraction of their pollinators to R.heldreichii, with beneficial results.The low frequency of pollinator visits to R.heldreichii flowers implies that this plant is not particularly preferred by its pollinators. Nevertheless, the plant relies on them for its survival. This may explain the prolonged duration of anthesis of each flower and, in spite of the limitations of the pollination process, it seems that the whole mechanism is quite efficient. The fact that it utilizes at least three different species of insects may be considered advantageous, since it may overcome unpredictable changes in pollinator availability. In spite of the relatively high natural mortality, its success in fruit setting is quite high. Additionally, it produces an extremely large number of minuscule seeds, which germinated readily. Its 'vulnerable' status is therefore not due to physiological constraints. The risks derive from increased human presence in the area for tourism, and especially from intense and uncontrolled plant collecting even though its area of occurrence is within the Mt Olympus National Park. On the basis of the above data, it could be argued that the reasons for its confinement to Mt Olympus are related to its specific habitat preference for limestone crevices. However, R.heldreichii cannot be considered as an alpine species since it is encountered as low as 400 m. It seems that conditions prevailing at lower altitudes make this plant less competitive in comparison to others. Therefore, lowland Olympus acts as a barrier, impeding further expansion of this plant, in the same way as island endemic species are restricted. Also, according to Legardón and García-Plazaola (2023), due to their rocky and mountainous habitat, members of the Gesneriaceae family have to face a great temperature variability and freezing temperatures, so they developed their resurrection ability and freezing tolerance.
Threats Information
The only threats reported are the impacts of increased tourism activities and of uncontrolled and intense collecting of plants (Vokou et al. 1990). The fact that most of the plants grow at inaccessible sites offers some protection. Also, the main part of the population grows at northern much less frequented slopes (Delipetrou 2011). According to the report on the main results of the surveillance under article 11 for annex II, IV and V species (Annex B), (Hellenic Republic 2007), pillaging of floristic stations is the main pressure and threat of an otherwise well-protected species.
Use and Trade Information
The species is cultivated in rock gardens and glass houses (Phitos et al. 1995).
Conservation Actions Information
According to the report on the main results of the surveillance under article 11 for annex II, IV and V species (Annex B), (Hellenic Republic 2007), because the taxon grows in inaccessible, rarely visited areas, it is relatively protected. Although no actual data exist to prove it in this factsheet, it is relatively safe to predict that this species’ conservation status should be estimated as Favourable. Monitoring of the population, the threat from collection and its adaptation to climate change, are considered obligatory. Ramonda heldreichii is listed on Annex IV of the Habitats Directive and under Appendix I of the Convention on the Conservation of European Wildlife and Natural Habitats (Bern Convention). The species is protected in Greece by the Presidential Decree 67/81 and it is included in the Red Data Book (Phitos et al. 1995). Most of the population of the plant is included in the National Forest Park of Olympos which is also a Natura 2000 site (GR1250001).The taxon is found in 9 Botanical Gardens (BCGI 2023).