Carex lepida Boott, Ill. Gen.

Jiménez-Mejías, Pedro & Escudero, Marcial, 2016, Notes on South American Carex section Schiedeanae and description of the new species Carex roalsoniana, Phytotaxa 260 (2), pp. 185-192 : 188-190

2. Carex lepida Boott, Ill. Gen. Carex 4: 211 (1867). ( Figs. 3–4 )

Lectotype (here designated): — ECUADOR. Pichincha: in the forest on the western side of Pichincha, 10000 feet, 1856, Jameson 881. ( K 000584629 (photo!) Figs. 3–4 ; isotypes E photo!, G photo!, K photo!, MICH photo!). Type material images hosted at JSTOR Global Plants (https://plants.jstor.org/).

Perennial; rhizomes elongated. Stems 9–29 cm long, 0.4–0.8 mm width in its middle length, shorter than or as long as the leaves, trigonous, with narrowly winged margins; flowering shoots without basal sheaths, sterile ones with soft scale-like sheaths, brown or straw-colored. Leaves flat or slightly M shaped in cross section, apparently hypostomatic, the uppermost of the flowering stems with a blade 20–35 cm long, the widest with a blade 3.4–4.4 mm width; ligule 3–3.7 mm, longer than wide, acute to subacute, reddish. Inflorescence 1.3–2.7 cm long, with 2–3 spikes, the uppermost androgynous or female, the other ones female, being the lowest one ± covered at the base by the lowermost bract; lowermost bract 1.8–10 cm × 1.1–3.6 mm, much longer than the inflorescence, sheathless; second lowermost bract 2.8– 0.7 cm × 3.6– 1.1 mm, longer than its spike. Spikes androgynous, or apparently all female in underdeveloped stems, sometimes the uppermost androgynous and the rest apparently female; uppermost spike the largest, 10.4–8.4 × 3–3.9 mm, with up to 12–16 utricles, when androgynous with the male part 1.1–1.7 mm long; lowermost spike 6.1–9.5 × 2.6–2.8 mm; cladoprophylls tubular. Male glumes hyaline, acute, crowded at the top of the androgynous spikes. Female glumes 1.2–1.5 × 0.4–1 mm, hyaline, obovate, with a central band greenish with 1 nerve, obtuse, mucronate, the ones from the middle part of the spike with the mucro 1– 0.4 mm long. Utricle 2.5–3.1 × 1.2–1.6 mm, elliptical, soft, membranaceous, greenish, nerveless except for the two lateral nerves, attenuated into a 0.4–0.7 mm smooth beak. Stigmas 2, very short, conspicuously convolute backward, reddish-brown; style base bulbous, deciduous, apparently not leaving remnant at the top of the achene. Achene 1.7 × 1.6 mm, suborbicular, narrowly biconvex; rachilla present, conspicuous, shorter than the achene.

Habitat and distribution: —Known only from the type collection, a population from an inexact location on the Ecuadorian Pichincha volcano, on the western side of the Andes, at an approximate altitude of 3000 m. According to the vouchers’ label the species seems to be part of forest understory, which approach its ecology to C. roalsoniana and C. subandrogyna (see notes above). The closest C. roalsoniana population seems to be about at a straight distance of 250 km south.

Phenology: —Unknown.

Etymology: —Apparently from the Latin lepidus –a –um, which translates for “gracious”.

Observations:—The presented description has been made from the high resolution images hosted at JSTOR Global Plants (https://plants.jstor.org/). It also takes into account the Latin diagnosis provided in the species protologue (Boott 1867) for those characters not easily observable in the pictures (e.g. male glumes; rachilla).

Carex lepida is known so far only from the type collection. This very distinctive species remained as incertae sedis to date. Despite G. A. Wheeler and A. A. Reznicek studied respectively the collections from G and MICH, they did not discussed its possible systematic placement. The unclear sectional placement of C. lepida seems to have been partly due to its superficial resemblance to species of subgenus Vignea , as the utricles bear 2-stigmas and the achenes are biconvex -characters that are not observed in any of the members of section Schiedeanae . Indeed, Boott (1867) compared C. lepida to C. divulsa Stokes (Withering 1787:1035), a species that belongs to subgenus Vignea (P.Beauv. ex T.Lestib.) Petermann (1849:602) . Nevertheless, we consider that C. lepida is probably part of the South American group of section Schiedeanae because of two readily similarities with C. roalsoniana and C. subandrogyna : 1- the inflorescence structure, with a terminal spike very shortly androgynous (in the best developed inflorescences, apparently entirely female in the smallest flowering stems), and the lowermost bract sheathless, much longer than the inflorescence, and somewhat sheathing its spike; 2- the very short style, with conspicuously convolute backward reddish-brown stigmas, and a bulbous style base. To these, it should be added the presence of a rachilla within the utricle. This character is mentioned in the protologue (Boott, 1867), but unfortunately we could not confirm it. The rachilla is a structure of relevant taxonomic importance in Carex . It is found in the members of the so-called Caricoid clade (see Molina et al. 2012), where North American species of section Schiedeanae are placed ( Global Carex Group 2016). This rachilla is only rarely found in aberrant individuals of the Vignea clade ( Molina et al. 2012; Global Carex Group, 2015).

Figures

FIGURE 3. Lectotype of Carex lepida Boott; note the elongated rhizome at the bottom of the specimen.

FIGURE 4. Detailed picture of the inflorescence of the lectotype of C. lepida Boott (A; K herbarium) and an isolectotype (B; K herbarium); note the biconvex utricles with two stigmas. Scale bar = 1 mm.