J. Eur. Orch. 47 (1): 71 – 76. 2015. Massimiliano Rempicci, Sergio Buono, Emanuele Gransinigh and Sara Magrini Epipactis helleborine subsp. orbicularis, a new orchid for the flora of Latium (Central Italy) Keywords Orchidaceae, Epipactis helleborine subsp. orbicularis, Latium, Central Italy. Summary Rempicci, M., Buono, S., Gransinigh, E & S. Magrini (2015): Epipactis helleborine (L.) Crantz subsp. orbicularis (K. Richt.) E. Klein, a new orchid for the flora of Latium (Central Italy).- J. Eur. Orch. 47 (1): 71-76. The occurrence of Epipactis helleborine (L.) Crantz subsp. orbicularis (K. Richt.) E. Klein in Latium (Central Italy) is here reported. The population, composed of only eight plants, was discovered within the Regional Park of Simbruini Mountains (Rome and Frosinone provinces), in a xeric slope on calcareous soil at an altitude of 916 m a.s.l. Zusammenfassung Rempicci, M., Buono, S., Gransinigh, E & S. Magrini (2015): Epipactis helleborine (L.) Crantz subsp. orbicularis (K. Richt.) E. Klein, eine für die Flora des Latiums (Mittelitalien) neue Orchidee.- J. Eur. Orch. 47 (1): 71-76. Die Autoren berichten über die Entdeckung eines kleinen Vorkommens von acht Pflanzen Epipactis helleborine (L.) Crantz subsp. orbicularis (K. Richt.) E. Klein auf dem Gebiet Regionalen Naturalparks “Monti Simbruini” (Provinzen Rom und Frosinone), neu für die Flora des Latiums. Die Gruppe besiedelt einen auf Kalk gründenden Hang mit Gebüsch auf 916 m ü.d.M. Bislang war dies Unterart nur aus norditalienischen Regionen von den Alpen bis zur Toskana bekannt, ausgenommen Aosta. In jüngster Zeit sind auch Fundmeldungen aus den Abruzzen und aus Kalabrien bekannt geworden. Journal Europäischer Orchideen 47 (1): 2015. 71 Riassunto Rempicci, M., Buono, S., Gransinigh, E & S. Magrini (2015): Epipactis helleborine (L.) Crantz subsp. orbicularis (K. Richt.) E. Klein, a new orchid for the flora of Latium (Central Italy).- J. Eur. Orch. 47 (1): 71-76. Gli Autori riportano la scoperta di una stazione di Epipactis helleborine (L.) Crantz subsp. orbicularis (K. Richt.) E. Klein nel Lazio (Italia centrale). Il popolamento è costituito da otto esemplari nel territorio del Parco Naturale Regionale “Monti Simbruini” (province di Roma e Frosinone) in un pendio cespugliato su terreno calcareo a 916 m s.l.m. * * * 1. Introduction On July 2010, during an excursion within the Regional Park of Simbruini Mountains, some of the authors (M.R., E.G. & S.B.) found a small population of orchids belonging to the genus Epipactis, with interesting morphological characteristics, especially in the leaves. On July 2012, after more observations in the field, such orchids were identified as Epipactis helleborine (L.) Crantz subsp. orbicularis (K. Richt.) E. Klein by two of the authors (M.R. & S.B.). 2. General distribution and ecology Epipactis helleborine subsp. orbicularis is distributed in the mountains of Central and South Europe, but its distribution area is still under study. In Italy it is reported for the Northern regions (Piemonte, Liguria, Lombardia, Emilia Romagna, Toscana, Trentino Alto-Adige, Veneto and Friuli Venezia-Giulia) (GIROS 2009: 244), and recently for Abruzzo (as Epipactis distans ArvetTouvet) (BONGIORNI et al. 2007, GRIEBL 2010) and Calabria (LINDIG & LINDIG 2012). It can be found in open woods, in the Alps mostly in thermophilic Pinus woods, and shrubby slopes, especially on calcareous soils, reaching the altitude of 2000 m a.s.l. (GIROS 2009). 3. Habitat and population data This population has been observed at Cesa Cotta (Vallepietra, Roma; UTMWGS84 33T 354750E 4642939N) within the Regional Park of Simbruini Mountains, at an altitude of 916 m a.s.l. It was composed of by eight plants in 72 Journal Europäischer Orchideen 47 (1): 2015. early or full bloom growing in a shrubby xeric slope on calcareous soils, near a road, with Juniperus sp. pl., Ostrya carpinifolia Scop., Clematis vitalba L., Robinia pseudacacia L., Fagus sylvatica L. subsp. sylvatica, Eupatorium cannabinum L. subsp. cannabinum, Campanula sp. pl.. Other orchids were present: Epipactis atrorubens (Hoffm.) Besser (full bloom) e Gymnadenia conopsea (L.) R. Br. in W. T. Aiton (pasted bloom). From a morphological point of view, Epipactis helleborine subsp. orbicularis is quite similar to Epipactis helleborine subsp. helleborine, but characterized by bigger plants, sometimes growing in clumps, and, especially, by orbicular, concave leaves. Such characteristics make it different also from E. helleborine subsp. latina W. Rossi & E. Klein, an orchid smaller in size, with oval rounded leaves, all piled in the lower part of the stem (GIROS 2009). From our observations in the field, the plants were quite robust with a large height range, between 28 and 53 cm, and grew individually, especially in partial shade. The leaves (3-5) are short and quite coriaceous, characterized by an orbicular shape and a sharp apex, and arranged obliquely or nearly erected along the stem; bracts are present close to the inflorescence. The inflorescences are lax, 9-18 cm long (with folded apex in the beginning of flowering) and 1432 flowered. Size, shape and colour of the flowers, are similar to those of Epipactis helleborine subsp. helleborine, well opened in full bloom. The sepals are lanceolate, pale green, with slightly wavy, purple margin and darker veins. The petals are smaller, ovate-lanceolate, acute, purple with evident darker veins. The hypochile is typically cup-shaped, dark inside, whitish outside. The epichile is folded down or flat, more or less pink and with two small protuberances. In the freshly bloomed flowers you can see the viscidium, while in the others only the separated pollen grains. The ovary is green, with reddish well developed stalk. Bracts greenish, lanceolate, longer than ovary. 4. Conclusion Epipactis helleborine subsp. orbicularis has only recently been reported by the authors as a new taxon for the flora of Latium (REMPICCI et al. 2014). We consider this finding worthy of reporting, because allows us to update the distribution of this orchid so rare in Central-Southern Italy where its distribution area is limited only to a few localities. Acknowledgments We wish to thank the editorial staff of JEO for German translation of the summary. Journal Europäischer Orchideen 47 (1): 2015. 73 Fig. 1: Epipactis helleborine subsp. orbicularis, habit, Cesa Cotta (Vallepietra, Roma), 7.7.2013, phot. M. Rempicci. 74 Journal Europäischer Orchideen 47 (1): 2015. Fig. 2-4: E. helleborine subsp. orbicularis, Cesa Cotta (Vallepietra, Roma), 7.7.2013. Fig. 2-3: close up, phot. MR; fig. 4: habitat, phot. S. Buono. Journal Europäischer Orchideen 47 (1): 2015. 75 References BONGIORNI, L., DE VIVO, R. & S. FORI (2007): Epipactis savelliana Bongiorni, De Vivo & Fori spec. nov. (Orchidaceae) nel gruppo della Majella (Abruzzo, Italia Centrale).- J. Eur. Orch. 39(1): 149-164. GIROS (2009): Orchidee d’Italia. Guida alle orchidee spontanee.- Cornaredo (Milano), Il Castello. 303 pp. GRIEBL, N. (2010): Die Orchideen der Abruzzen.- Ber. Arbeitskrs. Heim. Orchid. 27(2): 112-159. LINDIG, C. & D. LINDIG (2012): Nachweis von Epipactis helleborine subsp. orbicularis in der Region Kalabrien (Süditalien).- J. Eur. Orch. 44(2): 337348. REMPICCI, M., BUONO, S., GRANSINIGH, E. & S. MAGRINI (2014): Notulae alla Checklist della Flora vascolare Italiana 17: 2037 Epipactis helleborine (L.) Crantz subsp. orbicularis (K. Richt.) E. Klein (Orchidaceae).- Inform. Bot. Ital. 46(1): 74-75. Authors addresses Massimiliano Rempicci, G.I.R.O.S. Sezione “Etruria meridionale”; e-mail rempiccigomme@virgilio.it (corresponding author) Sergio Buono, G.I.R.O.S. Sezione “Etruria meridionale” c/o Via XXV aprile 6, Oriolo Romano (Viterbo) (Italy); e-mail sergood@libero.it Emanuele Gransinigh, G.I.R.O.S. Sezione “Etruria meridionale”; e-mail gransinigh@libero.it. Sara Magrini, Tuscia Germplasm Bank. Tuscia University. Largo dell’Università, Blocco C - Viterbo (Italy); e-mail magrini@unitus.it 76 Journal Europäischer Orchideen 47 (1): 2015.