Carex orbicularis subsp. kotschyana var. caucasica Ö. Nilsson, 1985

Jiménez-Mejías, Pedro, Rodríguez-Palacios, Giovanni E. & Martín-Bravo, Santiago, 2015, Taxonomic notes on some problematic Carex (Cyperaceae) names from SW Asia, Phytotaxa 219 (2), pp. 183-189 : 185-186

2) Carex orbicularis subsp. kotschyana var. caucasica Ö. Nilsson

Nilsson’s (1986) account of Carex sect. Phacocystis Dumort. for Flora of Turkey was one of the most important contributions towards an accurate treatment of this taxonomically complex group in the Middle East. However, the faint morphological boundaries between species, as well as the hybridization between them, have highly obscured the different taxonomic units in this area. This, together with the probably limited availability of reference materials to compare at the moment, misled Nilsson to a few wrong conclusions. For example, he conceived C. acuta Linnaeus (1753: 978) and C. kurdica Handel-Mazzetti (1914: 23) as taxa linked to different phytogeographical regions, Euro- Siberian and Irano-Turanian, respectively. However, some of the Turkish populations that he considered to be C. acuta match the morphological variation of C. kurdica (Jiménez-Mejías et al. 2014) , which increases the area of this taxon from the Kurdistan westwards to the Mediterranean. Similarly, he overlooked the presence of C. buekii Wimmer (1852: 83) in Turkey, due to its confusion with C. elata subsp. omskiana (Meinsh.) Jalas (in Jalas & Hirvelä 1964: 49) (see Jiménez-Mejías & Luceño 2011b; Jiménez-Mejías & Rodríguez-Palacios 2014).

The case of C. orbicularis subsp. kotschyana var. caucasica Nilsson (1985: 156) (from herein C. orbicularis var. caucasica ) is somewhat similar to what happened with C. kurdica . Carex orbicularis is a southern Asian species morphologically resembling both C. nigra and C. bigelowii Torr. ex Schweinitz (1824: 166) s.l. Its taxonomical identity has already been supported by molecular studies ( Schönswetter et al. 2008; Jiménez-Mejías 2011). Two widely distributed geographical races have been recognized: the eastern subsp. orbicularis (ranging roughly from Afghanistan to the Himalayas), and the western subsp. kotschyana (Boiss. & Hohen.) Kukkonen (1984: 389) , from the Caucasus to the Iranian mountain ranges called the Alborz and Zagros mountains ( Kukkonen 1998; Egorova 1999; Amini-Rad 2011). Nilsson (1986) described C. orbicularis var. caucasica to accommodate the northeastern Turkish populations (Caucasian-bordering) of what he thought to be deviant forms of C. orbicularis subsp. kotschyana . On the contrary, he considered the populations from the Armenian Highlands of southeastern Turkey to be typical C. orbicularis subsp. kotschyana var. kotschyana (from herein var. kotschyana ). Remarkably, despite he reported C. nigra from the Turkish Caucasus, he did not notice the affinities of his C. orbicularis var. caucasica with C. nigra . It is interesting to note that he distinguished C. orbicularis from C. nigra using characters that broadly overlapped with those that he also used to distinguish var. kotschyana from var. caucasica : “utricles broadly elliptic to almost orbicular […] basal sheaths dark reddish brown” in C. orbicularis , vs. “utricles ovate to obovate-elliptic […] basal sheaths pale brown” in C. nigra ; “basal sheaths dark reddish-brown to dark brown […] utricles […] rounded at apex […]” in C. orbicularis var. kotschyana , vs. “basal sheaths pale brown to dark-greyish brown […] utricles […] cuneate at apex […]” in var. caucasica . Egorova (1999) already noticed the remarkable differences between the var. caucausica and the var. kotschyana , and considered the former to “take an intermediate position between var. kotschyana and C. transcaucasica ”.

Despite the holotype specimen of C. orbicularis var. caucasica (see below) seems to be lost (L. Glancy, E herbarium, pers. comm.), we were able to study three paratype vouchers (Appendix I). Their morphology does match that of C. nigra (amphistomatic leaves; utricles nerved, cuneate at the top and attenuated into a beak), especially the subsp. transcaucasica , rather than C. orbicularis (hypostomatic leaves; utricles nerveless or faintly nerved, abruptly contracted into a short beak) (see Egorova (1999) and Jiménez-Mejías et al. (2014)). In addition, a sample matching var. caucasica morphology was included in a molecular study (Jiménez-Mejías 2011), and found to be placed within C. nigra genetic variability, with no apparent relation with C. orbicularis . It also helps to reject that C. orbicularis var. caucasica has a hybrid origin between C. nigra and C. orbicularis . Thus, we conclude that C. orbicularis var. caucasica should be considered a heterotypic synonym of C. nigra subsp. transcaucasica .