Thursday, March 16, 2023

[Botany • 2023] Carex quixotiana (Cyperaceae; sect. Phacocystis) • A New Iberian Endemic from Don Quixote’s Land (La Mancha, S Spain)

Carex quixotiana  Ben.Benítez, Martín-Bravo, Luceño & Jim.Mejías,

in Benítez-Benítez, Jiménez-Mejías, Luceño & Martín-Bravo, 2023.

Despite centuries of work, the basic taxonomic knowledge of the flora of the Iberian Peninsula is still incomplete, especially for highly diverse and/or difficult genera such as Carex. In this study, we conducted an integrative systematic study based on molecular, morphological and cytogenetic data to elucidate the taxonomic status of several problematic Carex populations from La Mancha region (S Spain) belonging to Carex sect. Phacocystis. These populations have been traditionally considered of uncertain taxonomic adscription, but close to C. reuteriana due to their morphological appearance and ecological preferences. A detailed morphological and cytogenetic study was performed on 16 La Mancha’s problematic populations (Sierra Madrona and Montes de Toledo) to compare them with the other Iberian sect. Phacocystis species. In addition, a phylogenetic analysis was conducted using two nuclear (ITS, ETS) and two plastid (rpl32‐trnLUAG, ycf6‐psbM) DNA regions, including representatives from all species of sect. Phacocystis. We found a significant degree of molecular and morphological differentiation that supports the recognition of La Mancha’s problematic populations as a new Iberian endemic species, described here as Carex quixotiana Ben.Benítez, Martín-Bravo, Luceño & Jim.Mejías. Our results reveal that C. quixotiana, unexpectedly, is more closely related to C. nigra than to C. reuteriana on the basis of phylogenetic relationships and chromosome number. These contrasting patterns reflect the taxonomic complexity in sect. Phacocystis and highlight the need for integrative systematic approaches to disentangle such complicated evolutionary scenarios.

Keywords: Cytogenetics, Iberian Peninsula, Mediterranean, morphometrics, new species, Phacocystis, phylogenetics, Quercus forest, taxonomy

Representative photos of Carex quixotiana
A habitat (riparian forest with Alnus lusitanica and Fraxinus angustifolia: Ciudad Real, Solana del Pino, Robledillo River; 57SMB17, UPOS-8924; C. quixotiana plants are in the lower right corner)
B habitat (stream in Quercus pyrenaica open forest: Ciudad Real, between El Viso del Marqués and San Lorenzo de Calatrava; 8CBB18, UPOS-16897; C. quixotiana are the tussocks along the stream)
C inflorescence D, E detail of terminal male and lateral androgynous spikes F detail of lateral female spikes and utricles (Ciudad Real, Fuencaliente, Minas del Horcajo, 54SMB17, UPOS-8922).

Analytical drawing of Carex quixotiana (Spain, Ciudad Real, Sierra Madrona)
 A habit B plant C androgynous spike D female glume E male glume F achene G utricle H details of papillae in the upper part of the utricle.
Drawing by M. Sánchez-Villegas.

 Carex quixotiana Ben.Benítez, Martín-Bravo, Luceño & Jim.Mejías, sp. nov.
Diagnosis: Similar in appearance to C. reuteriana Boiss. & Reut., from which it differs by the creamy-yellow, rarely reddish-brown basal sheaths (vs. orange to reddish-brown), amphistomatic leaves (vs. hypostomatic), and utricles with high papillae (vs. smooth or rarely with low papillae). It is also similar to C. nigra (L.) Reichard, from which it can be distinguished also by the creamy-yellow, rarely reddish-brown basal sheaths (vs. absent or dark brown when present), narrower leaves (1.8)2–3.2(4.7) mm (vs. 3–6(10) mm), and longer terminal male spike (18)20–60(85) mm (vs. (5)10–30 mm).

Carmen Benítez-Benítez, Pedro Jiménez-Mejías, Modesto Luceño and Santiago Martín-Bravo. 2023. Carex quixotiana (Cyperaceae), A New Iberian Endemic from Don Quixote’s land (La Mancha, S Spain). PhytoKeys. 221: 161-186. DOI: 10.3897/phytokeys.221.99234