Carex pachamamae Jim.

Jiménez-Mejías, P. & Reznicek, A. A., 2018, Additional notes on South American Carex sect. Schiedeanae (Cyperaceae) and description of the new species Carex pachamamae, Phytotaxa 340 (1), pp. 55-62 : 56-57

Carex pachamamae Jim. -Mejías & Reznicek, sp. nov. ( Fig. 2–3 )

Diagnosis:— This new species is similar to Carex subandrogyna G. A. Wheeler & Guagl. , which ranges from Tucumán in northern Argentina to southern Bolivia ( Wheeler & Guaglianone 2003, 2006; Jiménez-Mejías et al. 2016b). Carex pachamamae clearly differs from C. subandrogyna in its leaves (subcoriaceous, pale bluish-green, with no veins prominent adaxially, rarely two lateral ones scarcely prominent in the widest leaves of C. pachamamae , vs. weak, dark-green, with two conspicuously raised whitish lateral veins on the adaxial side more prominent than the rest in C. subandrogyna ) and utricles (pale whitish-green, with the sides concave in C. pachamamae , vs. green to brownish below, with the sides convex in C. subandrogyna ).

Holotype: — BOLIVIA. Sorata , 19 Apr 1920, E. W. D. Holway & M. M. Holway 548 (US 1178380! [barcode 02140964]; iso- NY 02817685 !) Figs. 2–3 .

Perennial, cespitose. Stems 21.2–48 cm long, 1.5–2.5 mm width in its middle length, ± as long as the leaves, with narrowly winged margins, scabrid its entire length, with pickles in both antrorse and retrorse directions; basal sheaths up to 1.7 cm high, scale-like, brown, splitting into fibers. Leaves flattish, V-shaped towards the base, pale bluish-green, subcoriaceous, straight or slightly outcurved, adaxially papillose, 5–8 mm wide, the uppermost of the flowering stem with a blade up to 24 cm long, the midvein more prominent than the others abaxially, no veins more marked than the others adaxially, only the widest leaves sometimes with two lateral veins slightly more apparent than the others on the adaxial side; ligule rounded, the free margins reddish; old leaf remnants present at the base of the flowering steams, brown to straw-colored, decomposing in fibers. Inflorescence 2.7–4.3 cm long, with 3 androgynous spikes, lowest one ± concealed by the lowermost bract; lowermost bract 7–10.6 cm × 4.5–6 mm at its widest point, erect, much longer than its spike, the other bracts progressively smaller towards the apex, also erect, the uppermost one shorter than its spike and supporting a utricle. Spikes androgynous, densely flowered, with up to 20 utricles, the pistillate part much more developed than the staminate one; uppermost spike the longest, 18 × 5 mm, with a staminate part 3–4 × 0.8–1.5 mm; utriculiform cladoprophylls present at the base of the lower spikes, ± 2 mm long, reddish, with a beak with ciliate margins, apparently containing an aborted female flower. Staminate glumes 1–1.5 × 1 mm, obovate, obtuse, hyaline, the central nerve green, sometimes continued at the tip into a diminutive short scabrid mucro. Pistillate glumes persisting on the spike rachis after the utricle falls, with a body 1.6–2 × 1.2–1.5 mm, obovate, hyaline, with a central band greenish, with 1–3 nerves, continued into a differently developed mucro, the glumes from the lower part of each spike with a scabrid awn up to 2 mm those of the upper part with a diminutive 0.1 mm mucro. Utricles 2.7–3.3 × 1.2– 1.7 mm, elliptic-fusiform, membranaceous, pale whitish-green or slightly reddish-tinged below, glabrous, nerveless, the faces concave, abruptly contracted into a smooth and shortly cylindric 0.2–0.3 mm long beak. Stigmas 3, very short, reddish-brown, densely papillose, conspicuously convolute backwards; style base bulbous, deciduous, leaving a flattish remnant at the top of the achene. Achene 2.2–2.3 × 1.2–1.5 mm, trigonous, the sides concave, more markedly proximally; rachilla absent; anthers ca. 0.6 mm long.

Habitat and distribution:—Known from only two collections from central and northern Bolivia, in the department of La Paz ( Fig. 1 ), at an approximate altitude of 2600–2900 m. Carex pachamamae seems to occur in the northwesternsoutheastern oriented portion of the north-central Bolivian Andes, where the ecoregion ( Ministerio de Medio Ambiente y Agua, 2013) is known as ‘proper’ Yunga or Bolivian Yunga, a mild humid forest (annual minimum of 17 oC). It contrast with the north-south oriented portion of the southern Bolivian Andes, which continues south to Argentina, and where the ecoregion is known as Bolivian-Tucumán forest, or Tucumán Yunga. These forest, that are the habitat of C. subandrogyna are much colder (annual minimum of 5 oC). The only indication about the habitat is provided in the herbarium label of the paratype collection “edges of a small stream in fairly deep shade […] Vegetation type: bosque nublado, small grove dominated by Prumnopitys sp. with various Myrtaceae genera”. This ecology is similar to the closely related C. subandrogyna , but at the same time distinct, since C. subandrogyna is known to grow exclusively in th Podocarpus and Alnus forests characteristic of the Tucumán Yunga ecorregion ( Wheeler & Guaglianone 2003, 2006; Jiménez-Mejías et al. 2016).

Phenology:—The specimens were collected fully ripe in February and April.

Etymology:—Dedicated to the Pachamama, goddess of Inca origin that personalizes the Mother Earth, and that is widely revered by the people of the Andes.

Additional material studied (paratypes): — BOLIVIA. Cochabamba, Prov. of Carrasco, remnant of forest alongside the dirt road which heads south out of Siberia (along the old highway to Santa Cruz), ca. 2900 m, Ritter & Wood 2886 (MO-5865945!; iso - MICH!, NHA digital image!) .

Observations:—The distinction of C. pachamamae from the closely related C. subandrogyna relies in utricle characters, as supported by the fact that the taxonomy of Carex mainly relies on reproductive structures ( Global Carex Group 2015, 2016). But some additional distinction was found also in leaves. There are numerous examples of Carex species that are primarily distinguished from their most closely related counterparts mainly by leaf characters. This is the case of C. hitchcockiana Dewey (1826: 274) and C. brysonii Naczi (1993:1 95) from North America (sect. Griseae Kükenthal (1909: 516); Naczi & Bryson 2002); C. dielsiana Kükenthal (1913: 10) and C. barbayaki Jiménez-Mejías & Roalson (2017: 283) from Eastern Asia (sect. Decorae (Kük.) Ohwi (1936: 338) ; Jiménez-Mejías & Roalson 2017); and C. laxula Boott (1867: 202) and C. sylvatica Hudson (1762: 353) in the Mediterranean (sect. Sylvaticae Rouy (1912: 470); Benítez-Benítez et al. 2017), among many others. The importance of leaf characters are somehow undervalued in many Carex groups, although a number of relatively recent studies has shown significant differences between species that look overall alike (e.g. Dean & Ashton 2008; Nakamatte & Lye 2010; Proctor & Bradshaw 2013).

The epithet “ Carex erythrogyne Nees ” found in the collection Holway & Holway 548 does not seem to have been ever published, as also noted in the case of the type collections of C. roalsoniana (see Jiménez-Mejías & Escudero 2016).

Figures

FIGURE 1. Known distribution of the four Carex section Schiedeanae species in South America: C. lepida (white circles), C. roalsoniana (black triangles), C. pachamamae (white squares), C. subandrogyna (black stars). Occurrences according to Wheeler & Guaglianone (2003, 2006), Jiménez-Mejías & Escudero (2016), Jiménez-Mejías et al. (2016b), and this paper.

FIGURE 2. Holotype of Carex pachamamae Jim.-Mejías (US 1178380 [barcode 02140964]).

FIGURE 3. Detailed pictures of the holotype of Carex pachamamae Jim.-Mejías (US 1178380 [barcode 02140964]). A. Inflorescence. B. Pistillate glumes. C. Utricle. D. Ripe achene. Scale bar = 1mm.