A new hybrid of Origanum (Lamiaceae) from the Aegean Island of Karpathos (Dodecanese, Greece): Origanum × karpathicum Author Cattaneo, Cristina Via Eleonora d’Arborea 12, 00162 Rome, Italy. Author Dimarchou, Theocharoula Pigadia Karpathos Greece zip code 85700 Author Özcan, Taner Department of Biology Education, Necatibey Education Faculty, Balıkesir University, Balıkesir. Author Dirmenci, Tuncay Department of Biology Education, Necatibey Education Faculty, Balıkesir University, Balıkesir. & Royal Botanic Gardens Kew, Richmond, Surrey, TW 9 3 AB, UK. text Phytotaxa 2022 2022-08-29 560 1 43 56 http://dx.doi.org/10.11646/phytotaxa.560.1.3 journal article 133172 10.11646/phytotaxa.560.1.3 a7e26d19-13fb-42ef-a2d5-709b16440f0c 1179-3163 7031191 Origanum × karpathicum Dirmenci, Cattaneo & Dimarchou nothosp.nov. ( Figs. 1‒2 , 5 ) ( Origanum onites L. × O. vetteri Briq. & Barbey ) Type: Greece . Dodecanese Archipelago : Karpathos , Volada , Mt. Kollas , eastern calcareous rocky slopes with phrygana, 830-920 m , 29.05.2021 , Cattaneo 1771 ( Holotype : K, isotypes: E, GAZI, herb. Cattaneo) . Diagnosis: ― Characters of Origanum × karpathicum are intermediate between those of its parents characters ( Figure 2a–h , 5A–D ), but it differs from O. onites , by the stems sparsely to densely pilose (not hirsute), leaves obtuse at apex (not acute to acuminate), and densely pilose (not hirsute), bracts 3‒5 × 2‒3.2 mm and long pilose (not 2.5‒3 × 1.7‒2.2 mm and hirsute), calyx usually 2-lipped, 3.5‒4 mm long and long pilose (not 1-lipped, 2‒2.5 mm long and pilosellous), upper and lower teeth usually present (not upper lip entire or denticulate), corolla 3.5‒5 mm long (not 3.5‒4 mm long). It differs from O. vetteri , by the stems 9‒15 cm tall and pilose (not 2‒10 cm tall and lanate-pilose), leaves 5‒12 × 4‒8 mm (not 2‒8 × 1‒5 mm ), bracts 3‒5 × 2‒3.2 mm (not 5‒7 × 2.5‒4 mm ), calyx 3.5‒4 mm long (not 4‒5 mm long), corolla white and 3.5‒5 mm long (not pink and 5‒6 mm long). FIGURE 3 UPGMA cluster tree (a) and PCA diagram (b) realized on the systemic analysis of morphological data Description:― Subshrubs, 9‒15 cm tall, many stemmed from the base, branches of first order present or not, second order absent; flowering stems slender and ascending to erect, sparsely to densely pilose with minutely glandular papillae and sessile glands. Leaves 4–9 pairs on stems, 5‒12 × 4‒8 mm , broadly ovate to rounded, petiole 1‒5 mm long, rounded to cordate at base, obtuse at apex, entire at margins, flat or sometimes slightly revolute, densely pilose with minutely glandular papillae and sessile glands on both surfaces. Inflorescence erect, corymbose or not, sometimes slightly nodding; spikelets 5‒10 × 5‒8 cm , subglobose or cylindric to conical. Bracts imbricate, 3‒6, 3‒5 × 2‒3.2 mm , elliptic to obovate, green to purplish, acute to acuminate, densely pilose with minutely glandular papillae and sparsely sessile glands on outer surface, glabrous to sparsely pilose on inner surface, long and densely ciliate at margins. Calyx 2-lipped, tubular-campanulate, 3.5‒4 mm long, sparsely to densely pilose with sparsely to densely sessile glands and glandular papillae; teeth long pilose; upper lip usually 3-toothed, teeth 0.1‒0.5 mm long, sometimes absent or reduced; lower lip distinctly 2-toothed, teeth 0.2‒1.5 mm long. Corolla 3.5‒5 mm long, slightly exserted from calyx, pilose with sessile glands. Style exserted from corolla, unequally bilobed. Stamens 4, included in corolla and immature. Nutlets unknown. In cluster analysis ( Figure 3a ) of the quantitative morphological characters, three main groups were distinguished. According to UPGMA diagram, O. onites differs from O. vetteri and their putative hybrid. Hybrid and O. vetteri main clade is the sister group of O. onites . Although each taxon is a group, cluster analysis according to morphological characters shows us that the hybrid taxon is located between the two parents taxa. Besides, the hybrid is located more closely with O. vetteri . In PCA diagram based on morphological characters ( Figure 3b ), the first component explains a significant part of the variation between species (86.085%). The next two components explain respectively 9.3381% and 3.407% of the variation. These components explain almost all the variation between taxa. The effects of the characters on the components of taxa are presented in Figure 3b . Among the characters explaining the variation between taxa, bract length had the highest value, while bract width had the least effect. However, all characters contributed almost equally to explaining variation between taxa.