ACTA BOT. CROAT. 80 (2), 2021 215 Acta Bot. Croat. 80 (2), 215–216, 2021 CODEN: ABCRA 25 DOI: 10.37427/botcro-2021-017 ISSN 0365-0588 eISSN 1847-8476 Short communication Bromus diandrus (Poaceae), an addition to the Bulgarian flora Georgi Kunev Sofia University “St. Kliment Ohridski”, Faculty of Biology, Department of Botany, Dragan Tzankov” Blvd. no. 8 “, Sofia 1164, Bulgaria Abstract – The current report discusses Bromus diandrus, a new species in the flora of Bulgaria. A concise description of its morphological features with an emphasis on the characters that distinguish it from the already known represen- tatives of Bromus sect. Genea in the country is presented. The newly established locality is characterized floristically and ecologically. The probabilities of the native or alien origin of the studied population are also discussed. Keywords: Anisantha diandra, Bromus, dune vegetation, Grate Brome, native species Introduction Bromus diandrus Roth (syn.: Anisantha diandra (Roth) Tutin ex Tzvelev) belongs to the infrageneric sect. Genea Dumort., which in Europe comprises 8–11 taxa with species or subspecies rank (Smith 1980, Sales 1993, Valdés et al. 2009). The section accommodates mostly ruderal species with annual or biennial life cycles. Three taxa from the sec- tion, B. sterilis L., B. madritensis L. and B. tectorum L. have previously been confirmed from Bulgaria (Georgiev 1963, Assyov and Petrova 2012). The similar B. rigidus Roth (re- ported as B. maximus Desf.) was noted by Stojanov et al. (1967) as having been erroneously recorded in Bulgarian flora without any reference. The aim of the current report is to provide a brief de- scription of the species, underlining the characters distin- guishing it from other representatives of the section, to com- ment on aspects of its environmental requirements, habitat affiliation and the probable origin of the studied population. Materials and methods The species was observed during field research into the coastal sands at Irakli on the Black Sea coast, about 6 km south of the city of Obzor, on 15 August, 2020. The distinc- tive features were noted in the field and after examination of the collected specimens under a stereomicroscope. To verify the identification, the collected specimens were com- pared with herbarium materials kept at SO (Nos. 07440, 82367) and SOM (Nos. 113297, 137672, 140540) or as digital collections from E, P, B, WU and MW herbaria, available at GBIF (2019). The taxonomy of the species follows Smith (1980). Exsiccata are deposited at SO (Nos. 108028–108030) and SOM (Nos. 177047, 177048). Habitat description is based on the author’s personal observations. The names of the accompanying species or subspecies are quoted after Assyov and Petrova (2012) and/or Valcheva et al. (2020). Results and discussion Bromus diandrus is distinctive by reason of its robust appearance; lax and nodding one-sided panicles (Fig. 1a); hirsute panicle axis and stem below the panicle (Fig. 1b); larger glumes, lemmas, lemma lobes and awns as compared with the other representatives of sect. Genea from Bulgaria (Fig. 1c). From B. sterilis it differs also by the general outline shape of the inf lorescence, the usually shorter panicle branches, which are not arched-pendulous, as well as the narrow and longer callus scar. From the similar B. rigidus, it is distinguished mainly by the callus scar, ovate, rounded at the end (vs. elliptic, pointed at the end), and by the pres- ence of conspicuous constriction at the base of lemma (Fig. 1d). For more comprehensive description of the representa- tives of the sect. Genea refer to Sales (1993). Bromus diandrus is a winter annual species native to the Irano-Turanian, Pontic and Mediterranean regions but in- troduced elsewhere as an alien weed (CABI 2020). Current- ly it has global distribution and occupies coastal sands or various types of anthropogenic habitats such as crop fields, waste places, roadsides, etc. (GBIF 2019, CABI 2020). Sev- eral locations are known from the coastline of the Black Sea and its surroundings - Crimea, southwestern Russia, Geor- gia and Turkey (GBIF 2019). Most probably, the closest doc- umented locality within the native range of the species to * Corresponding author e-mail: gikunev@uni-sofia.bg KUNEV G 216 ACTA BOT. CROAT. 80 (2), 2021 the one at Irakli is in the vicinity of Edirne, European Tur- key (Webb 1966). More recently, the species was reported for the flora of North Macedonia, preliminarily accepted as native (Kostadinovski et al. 2019). The site of Bromus diandrus at Irakli has the approxi- mate coordinates in WGS84: 42°44’53.22”N, 27°53’21.44”E. The habitat type is identified as B1.324 Pontic white dunes (EUNIS 2007). The vegetation constitutes a narrow (5-15 m wide), sparsely vegetated linear strip, between a non-veg- etated sand beach and the foot of sea cliff slope. The species composition is typical for the dune vegetation from the western Pontic region. Most abundant of the recorded spe- cies were Leymus racemosus (Lam.) Tzvelev subsp. sabulosus (M.Bieb.) Tzvelev, Elymus farctus (Viv.) Runemark ex Melderis subsp. bessarabicus (Savul. et Rayss) Melderis, Eryngium maritimum L., Cakile maritima Scop. subsp. euxina (Pobed.) Nyár., Salsola tragus L. subsp. tragus and Vulpia fasciculata (Forsskal) R.M. Fritsch. Much less abun- dant or present as single individuals were Ammophila arenaria (L.) Link, Peucedanum obtusifolium Sm., Stachys maritima Gouan, Euphorbia peplis L., Lactuca tatarica (L.) C.A.Mey., Xanthium orientale L. subsp. italicum (Moretti) Greuter, Crambe maritima L. and Pancratium maritimum L. In addition, some species typical for dry grassland communities were also recorded: Bromus tectorum L., Hypochaeris radicata L., Centaurea salonitana Vis., Allium guttatum Steven, Silene dichotoma Ehrh., Alyssum hirsutum M.Bieb., Carthamus lanatus L., Pyrus communis L. subsp. pyraster (L.) Ehrh. At its first Bulgarian site, Bromus diandrus grows in more or less dense patches unevenly distributed over an ar- ea of less than 0.1 ha. Between 15-120 culms per m² were counted, while the overall area covered by the species alone was approximately 200 m². Considering the number of in- dividuals and the population density, probably the species occurred in this area a long time ago. The rapid growth of tourism and its supporting infra- structure during the last 20 years has affected many natural sites along the Bulgarian Black Sea coast. As a consequence, tourism can be expected to have affected the dune vegetation at the studied locality in terms of the introduction of untypi- cal native or alien f lora. However, excluding Xanthium orientale subsp. italicum, no other alien species were observed. This is in agreement with the evaluation of Valcheva et al. (2020), who reported limited diversity and abundance of alien (incl. invasive) species in the coastal vegetation of Bulgaria. In conclusion, it can be stated that the locality of Bromus diandrus at Irakli is insignificantly affected by trampling, unregulated campsites, campfires or other type of distur- bances, thus its current state could be evaluated as close to natural. Moreover, the species is found within its native range, the conditions correspond to its ecological require- ments while the state of its population proves that it is well adapted to the environment at this locality. Therefore, B. diandrus could be presumably regarded as native for the Bulgarian flora. However, more studies are needed, particularly in the regions of the country influenced by more or less typical dry Mediterranean climate in order to determine the status of the taxon reported here accurately. References Assyov, B., Petrova, A. (eds.), 2012: Conspectus of the Bulgarian vascular flora. Distribution maps and floristic elements, ed. 4. BBF, Sofia. CABI, 2020: Bromus diandrus (great brome), Invasive Species Compendium. Wallingford, UK: CAB International. Re- trieved November 21, 2020 from https://www.cabi.org/isc/ datasheet/10024 EUNIS, 2007: EUNIS habitat classification 2007, revised 2012, amended 2019. Retrieved November 21, 2020 from https:// www.eea.europa.eu/data-and-maps/data/eunis-habitat-clas- sification GBIF, 2019: Bromus diandrus Roth in GBIF Secretariat (2019), GBIF Backbone Taxonomy, Checklist dataset https://doi. org/10.15468/39omei. Retrieved November 21, 2020 from https://www.gbif.org/species/2703760 Georgiev, T., 1963: Bromus L. In: Jordanov, D. (ed.), Flora Reipu- blicae Popularis Bulgaricae, vol. 1, 420–433. In Aedibus Ac- ademiae Scientiarum Bulgaricae, Serdicae (in Bulgarian). Kostadinovski, M., Ćušterevska, R., Matevski, V., 2019: Anisan- tha diandra (Roth) Tutin and Ochlopoa infirma (Kunth) H. Scholz – New species of Poaceae family in Republic of Mace- donia. Contributions. Section of Natural, Mathematical & Biotechnical Sciences 40, 273–276. Sales, F., 1993: Taxonomy and nomenclature of Bromus sect. Ge- nea. Edinburgh Journal of Botany 50, 1–31. Smith, P.M., 1980: Bromus L. In: Tutin, T.G., Heywood, V.H., Burges, N.A., Moore, D.M., Valentine, D.H., Walters, S.M., Webb, D.A., (eds.), Flora Europaea, vol. 5, 182–189. Cam- bridge University Press, Cambridge. Stojanov, N., Stefanov, B., Kitanov, B., 1967: Bromus L. In: Flora of Bulgaria, ed. 4, vol. 2, 132–137. Nauka i Izkustvo, Sofia (in Bulgarian). Valcheva, M., Sopotlieva, D., Apostolova, I., 2020: Current state and historical notes on sand dune flora of the Bulgarian Black Sea Coast. Flora 267, 151594. Valdés, B., Scholz, H., von Raab-Straube, E., Parolly, G., 2009: Poaceae (pro parte majore). Euro+ Med Plantbase-the infor- mation resource for Euro-Mediterranean plant diversity. Re- trieved December 28, 2020 from http://ww2.bgbm.org/Eu- roPlusMed/ Webb, D.A., 1966: The flora of European Turkey. In: Proceedings of the Royal Irish Academy. Section B: Biological, Geological, and Chemical Science, pp. 1–100. Royal Irish Academy. Fig. 1. Distinguishing features of Bromus diandrus: a – one-sided semi-nodding panicle, b – upper stem and panicle axis, c – glumes and first lemma with up to 60 mm long awn, d – ovate callus scar with notable constriction at lemma’s base.