Aethionema saxatile rhodopaeum (D.K. Pavlova) Constantinidis, Kougioumoutzis & Kalpoutzakis 2017

Doumas, Panayiotis, Goula, Katerina & Constantinidis, Theophanis, 2022, Thirty-two new and noteworthy floristic records from north-eastern Greece, Biodiversity Data Journal 10, pp. 81817-81817 : 81817

Aethionema saxatile rhodopaeum (D.K. Pavlova) Constantinidis, Kougioumoutzis & Kalpoutzakis 2017

Aethionema saxatile subsp. rhodopaeum (D.K. Pavlova) Constantinidis, Kougioumoutzis & Kalpoutzakis in Plant Biosyst. 151 (1): 115 (2017)

Materials

Type status: Other material. Occurrence : recordedBy: P. Doumas; Taxon : scientificName: Aethionema saxatile subsp. rhodopaeum; family: Brassicaceae ; genus: Aethionema ; specificEpithet: saxatile; infraspecificEpithet: rhodopaeum; taxonRank: subspecies; Location : continent: Europe ; country: Greece; stateProvince: Nomos Xanthis ; verbatimLocality: between the Villages of Potamochori and Korifi , close to Kompsatos river belt; verbatimElevation: 550 m; verbatimLatitude: 41°14′; verbatimLongitude: 25°04′; Identification: identifiedBy: P. Doumas & Th. Constantinidis; Event: eventDate: 27 March 2019; habitat: rocky, serpentine slope with scrub, in deciduous Quercus forest; Record Level: collectionID: s.n.; institutionCode: ATHU; basisOfRecord: Specimen

Taxon discussion

A new record for the Greek flora.

As currently understood, Aethionema saxatile (L.) R.Br. is quite variable in Greece. It consists of four subspecies with a more or less distinct geographical distribution that deserve the rank of subspecies ( Andersson et al. 1983, Kougioumoutzis et al. 2017). Certain specimens from NW Greece resemble a fifth subspecies, subsp. Aethionema saxatile saxatile , but statistical analyses of morphological characters showed that they cannot be placed with certainty under either subsp. Aethionema saxatile oreophilum or subsp. Aethionema saxatile saxatile . A related species, Ae. rhodopaeum D.K. Pavlova ( Pavlova 2007), so far considered endemic to Bulgaria, was treated as another subspecies of the Ae. saxatile group by Kougioumoutzis et al. (2017). It is a serpentine endemic with a local distribution to suitable geological substates of the Rodopi area.

The cited specimen, collected in Greece in 2019 (Fig. 12), has a combination of features that place it under Ae. saxatile subsp. rhodopaeum : a) short stems, usually less than 10 cm long; b) unilocular fruits present at a relatively high proportion (>30-40% of total fruit number); c) lack of appendages on filaments; d) dark pink to pink-purplish petals and e) a particular preference for the rocky, serpentine habitats of the Kompsatos River valley.

The following key helps in distinguishing all Αethionema Aethionema saxatile taxa found in Greece, Table 1 .

Following a morphological and statistical approach, the close taxonomic proximity of subsp. Aethionema saxatile rhodopaeum to the rest of the Ae. saxatile taxa is unquestionable. However, a recent phylogenetic reconstruction places it away from Ae. saxatile as it forms a monophyletic group with the annual Asiatic Ae. syriacum (Boiss.) Bornm. and the perennial Ae. orbiculatum (Boiss.) Hayek, a local endemic of Mt. Athos, Greece ( Mohammadin et al. 2017). A more detailed investigation of the whole group may be necessary in the future.

subsp. Aethionema saxatile rhodopaeum was previously known from a few, small populations in Bulgaria, where it has been assessed as Endangered, according to the IUCN Categories and Criteria ( Pavlova 2007). The Greek population was found at a distance of 11 km south of the Greek-Bulgarian border, consists of a few dozens of plants and covers an area of just a few square metres (Fig. 11 ). Its discovery expands the extent of occurrence, area of occupancy and population size of this rare plant; however, it remains an Endangered species at global level, according to Criteria [B1ab(ii iv) + 2ab(ii iv)]. At national level, the single Greek population fits the Category of Critically Endangered [B1ab(i ii iii iv) + 2ab(i ii iii iv)] ( IUCN 2012).

Figures

Figure 11. Distribution map of Onosma kittanae, Aethionema saxatile subsp. rhodopaeum and Silene fetlerii in Greece and Bulgaria.