Carex recondita Muñoz-Schüler, Martín-Bravo & Jim. Mejías, 2024

Muñoz-Schüler, Paulo, Morales-Alonso, Ana, Márquez-Corro, José Ignacio, Arroyo, Mary T. K., Martín-Bravo, Santiago & Jiménez-Mejías, Pedro, 2024, Carex recondita Muñoz-Schüler, Martín-Bravo & Jim. Mejías (Carex section Junciformes Kük., Cyperaceae), a new sedge species from the Andes of central Chile, PhytoKeys 243, pp. 15-30 : 15-30

Carex recondita Muñoz-Schüler, Martín-Bravo & Jim. Mejías sp. nov.

Diagnosis.

Carex recondita is similar to C. austroamericana , from which it is distinguished by its longer leaves up to 9 cm long (versus 5 cm long in C. austroamericana ), narrower spikes up to 3.5 mm wide (versus 3.5–6 mm wide), and weakly veined ellipsoid, obovoid or suborbicular utricles, with a flattened stipitate base (versus strongly veined obovoid utricles, with a rounded or flattened stipitate base).

Type.

Chile. Región Metropolitana de Santiago: Provincia de Santiago, Farellones , camino al centro de ski Valle Nevado , Tres Puntas , 2750 m. a. s. l., 33 ° 21.39183 ' S, 70 ° 15.45538 ' W, 16 January 2023, P. Jiménez Mejías, J. I. Márquez Corro, S. Martín Bravo & P. Muñoz Schüler 12 PJM-CL 23 (holotype: CONC 193519 ; isotypes: EIF 17307 , UPOS) .

Description.

Plants low-growing, densely caespitose 3–10.2 cm tall from the base of the shoots to the tip of the leaves, acaulescent or nearly so. Leaves numerous, up to eight per shoot, much longer than the flowering shoots and concealing them, 2–8.2 cm long, canaliculate but flattish distally, stiff to slightly flexuose. Flowering shoots elevated on erect stalks of 1.2–4.4 cm long formed by the basal leaf sheaths, with the portion between the insertion of the distal-most leaf and the proximal-most bract inconspicuous, up to 1.2 mm long. Inflorescence a single, terminal, androgynous, subglobose spike, 4.3–6.2 mm long and 2.8–3.5 mm wide, subtended by an involucral bract, with a glumaceous base and prolonged into a 5.8–9.1 mm long antrorsely scabrid or smooth setaceous portion. Staminate part concealed by the pistillate portion, 2 - flowered. Pistillate part 4–5 flowered, sometimes with an extra infertile flower borne by the involucral bract; glumes ovate to widely elliptical, 3.1–4.1 mm long and 1.4–2.3 mm wide, glabrous, with wide hyaline margins contrasting with a narrow green middle strip, veinless, attenuated distally into an awn, the 2 - proximalmost glumes with a 1.9–3.3 mm long awned portion that usually surpasses the whole inflorescence, distalmost glumes with a 0.6–0.9 mm long mucronate apex. Utricles 2.4–3 mm long and 1.2–1.8 mm wide, ellipsoid, suborbicular, ovoid or sub-obovoid, obscurely trigonous in cross section, green to pale green, with 2 prominent lateral veins dark greenish, contrasting with the rest of the body, veinless or 2–5 weakly veined adaxially and 1–4 veined abaxially, glabrous to sparsely hispidulous on its distal half, with the lateral veins hispidulous to ciliolate on its distal ⅔ portion, attenuated or constricted proximally into a sub-stipitate base 0.4–0.8 mm long, often flattened in cross section, constricted distally into a short, bidentate, and pale beak 0.3–0.6 mm long. Achenes 1.9–2.2 long and 1.2–1.6 mm wide, broadly elliptical to sub-obovoid, obscurely trigonous, often flattened, greenish, more or less constricted proximally into a sub-stipitate base and attenuated distally into a short beak. Rachilla often absent, when present 0.6–0.9 mm long, linear, margins smooth. Stigmas 3. Anthers 3.

Phenology.

The phenology of this species is poorly understood. A fully flowering specimen with some ripe utricles was collected in mid-late December, while a specimen with entirely ripe utricles bearing some female flowers was collected in mid-January. According to these observations we infer that the flowering period for the new species is likely to range from mid-November to late December with mature individuals bearing ripe utricles from mid-late December onwards. This agrees with the plant community peak flowering period at 2935 m. a. s. l. (late-December to early-January) in an adjacent high Andean valley ( Arroyo et al. 1981), thus our species should flower during the first half of the flowering season.

Etymology.

The specific epithet recondita (female) refers to the Latin word recondito (male), meaning something hidden or occult, apropos the acaulescent inflorescence and low-growing habit of this species.

Distribution and habitat.

Carex recondita occurs in the area of La Parva and Farellones-Valle Nevado ski circuits, in the Andes of the Metropolitana region of Santiago (see Fig. 4 ), and has been reported to grow between 2750–2880 m. a. s. l. The new species occurs in the central Chilean Andes, in an area characterized by a semi-arid Mediterranean-type influence climate ( Arroyo et al. 1981) and it grows in the alpine cushion plant belt ( Cavieres et al. 2000), on steep slopes around 650 m of elevation above a climatically depressed Kageneckia angustifolia D. Don treeline. Phytogeographically, this area and elevation in the high Andes falls in the Cuyano-Pikumche district of the Altoandean Province of the southern Andes ( Biganzoli et al. 2022). Snow is received from May-June to October-November, depending on the year. Carex recondita was growing on a south-facing slope next to an important road leading from Farellones mountain town to Valle Nevado ski resort, forming dense tufts in a habitat dominated by the cushion-forming umbellifer Azorella ruizii G. M. Plunkett & A. N. Nicolas (Fig. 1 ). Other common species in the area include Acaena pinnatifida Ruiz & Pav. , Adesmia corymbosa Clos , Anarthrophyllum cumingii (Hook. & Arn.) F. Phil. , Chaetanthera euphrasioides (DC.) F. Meigen , Haplopappus scrobiculatus (Nees) DC. , Hypochaeris clarionoides (J. Remy) Reiche , Hordeum comosum J. Presl , Noccaea magellanica (Comm. ex Poir.) Holub , Perezia carthamoides (D. Don) Hook. & Arn. , Poa holciformis J. Presl , Quinchamalium chilense Molina , Rytidosperma pictum (Nees & Meyen) Nicora and Senecio pentaphyllus Phil. The exotic Taraxacum officinale F. H. Wigg. , an invasive Palearctic species at high elevations in the central Chilean Andes ( Cavieres et al. 2008), can also be locally common. This plant is currently known from only three points. Two are located on two contiguous slopes, with approximately 280 meters of distance between each other, while the third point is located approximately 3 km Northwest in a straight line from the closest known point (Fig. 4 ). Further fieldwork might expand its known presence within the area by searching in environmentally similar localities.

Vernacular name.

We propose the common name for this species to be “ Carex de las nieves ”.

Conservation status.

C. recondita has an area of occupancy (AOO) smaller than 10 km 2, and only a single population (three subsets) of approximately <200 individuals has been reported. Although the entire known individuals of this species are located in protected land (Yerba Loca Nature Sanctuary), the management of the area that is effectively being protected only includes the watershed of the La Yerba Loca stream, which is located 4 km west (in straight line) and approximately 1000 m below the area in which C. recondita grows. Notwithstanding this, the new species grows within one of the most crowded ski circuits of Chile (La Parva and Farellones-Valle Nevado circuit), on an area contiguous to one of its main roads, which has also been affected by exotic plant invasions ( Cavieres et al. 2008). Road construction and maintenance works seem like a plausible threat to the future conservation of the population. The scarcity of observed individuals and the lack of previous reports or collections for this area suggests that C. recondita might be extremely rare and thus vulnerable to disturbances. The real extent of its natural distribution is unknown, and its area of occurrence might be greater than estimated by current data. However, and according to our data and observations, we propose that this species is better assessed as ‘ Critically Endangered’ (CR; B 2 ab (ii-iv) + C 2 a (i )), according to the IUCN Red List criteria ( IUCN 2017). Further searching of this species will contribute to expanding the knowledge about its presence and might help proposing a more robust assessment.

Notes.

C. recondita is a tuft-forming species with stiff leaves and an acaulescent spike burrowed between the leaves, a type of growth form shared with many other Patagonian species of sect. Junciformes and recurrent in South American Carex species (see Jiménez-Mejías et al. 2021 b). This type of growth might be an adaptation to harsh environments such as the high Andes or the Patagonian steppe ( Körner 2021, pp. 37–38). This made C. recondita remain unnoticed until now, despite growing just beside a busy road in a popular skiing holiday area barely over one hour by road from Santiago, the most populated city of Chile. Some of the studied material included inflorescences with involucral bracts bearing - apparently- infertile female flowers.

Additional specimens examined (paratypes).

Chile. Región Metropolitana de Santiago: Provincia de Santiago, camino entre Farellones y Valle Nevado , laderas por debajo de la curva 14, piso altoandino, 2853 m a. s. l., 33 ° 21.46188 ' S, 70 ° 15.32352 ' W, 20 December 2022, M. T. K. Arroyo, V. Robles, K. Robles, M. Acevedo & L. Retamal 29576 ( CONC) . Provincia de Santiago, Farellones , a 1 km de la Parva . 2674 m a. s. l., 33 ° 20 ' S, 70 ° 17 ' W, 1 March 2007, M. Mihoc 777 ( CONC 178536 ) .

Figures

Figure 1. Carex recondita Muñoz-Schüler, Martín-Bravo & Jim. Mejías A, B aerial and frontal view of the plant and a spike C, D habit E two of the authors looking for more specimens of C. recondita on its habitat, the road can be seen at the upper-left portion of the picture F habitat of C. recondita, showing dominant Azorella ruizii (green cushions) and Anarthrophyllum cumingii (prostrate shrub with orange-yellow flowers). Photos by P M-S (A – E) and MTKA (F).

Figure 4. Occurrence map of Carex sect. Junciformes species cited in this work A occurrence map of five Patagonian species of Carex sect. Junciformes. Species locations are depicted in colored circles and some cities are represented as black squares B detailed map of the area of occurrence of C. recondita (light-green circles). Another species occurring in the area, C. argentina, is depicted by red circles. The highlighted region corresponds to the Yerba Loca Nature Sanctuary. Altitude was represented by a color palette and contour lines, representing elevation every 200 meters. For orientation purposes, some landmarks were depicted on the map.