Carex via-incaica Jim.

Jiménez-Mejías, Pedro & Roalson, Eric H., 2016, Two new species of Carex (Cyperaceae) from northern South America, Phytotaxa 266 (1), pp. 21-26 : 21-23

Carex via-incaica Jim. -Mejías & E.H.Roalson, sp. nov.

Diagnosis: —This new species is similar to C. toroensis G.A. Wheeler (1989: 182) from which it differs by its rachilla (linear, 0.1 mm wide, antrorsely scabrid in C. via-incaica vs. ovate to lanceolate, 0.2–0.3 mm wide, with the margins smooth or at most with very weak incipient prickles at the apex in C. toroensis ), and by the lowermost bract (22– 17 mm long in C. via-incaica vs. 6.4– 3.4 mm long in C. toroensis ). Carex via-incaica also resembles C. vallis-pulchrae Philippi (1896: 487) , especially in the morphology of the utricles, but both can be readily distinguished by the achenes (biconvex in C. via-incaica vs. trigonous in C. vallis-pulchrae ) and the glumes (without hyaline margin in C. via-incaica vs. with a conspicuous hyaline margin in C. vallis-pulchrae ). See Wheeler (1989) for detailed descriptions of the two compared species and a key for the South American species of Carex sect. Aciculares (Kük.) G. Wheeler (1989: 174) .

Type:— ECUADOR. Cotopaxi: Parque Nacional Cotopaxi, ca. 0° 40’ S, 78° 30’ W. Faldas norte de Rumiñahui. Páramo y laderas rocosas. 4100–4300 m. 20 Oct 1982. H. Balslev et al. 3360 (Holotype: NY!; isotype material presumably at QCA). Fig. 1 .

Perennial; rhizomes long, ±ascending, covered by fibrous sheath remains at the distal part, naked proximally and thus 0.3– 0.2 mm wide at the middle part of the internodes. Stems 4.5– 3.5 cm tall, 0.4– 0.35 mm wide at the middle, smooth, terete, trigonous below the inflorescence, ±sulcate, especially at the top. Leaves linear, soft, slightly longer than the stems, the widest 0.6– 0.4 mm at the middle, smooth, weakly antrorsely scabrid at the apex, ±trigonous to flattish or canaliculated, apparently light green; uppermost leaf on every stem with a blade 5– 3.5 cm long, ligule 0.3– 0.2 mm long, truncate to obtuse, orangey-brownish, and sheath orangey-brownish, hyaline on the side opposite to the blade; basal sheaths present at the base of the sterile shoots, scale-like, without blade, brownish; old leaf remains present at the base of flowering shoots, light-brownish to straw-colored. Inflorescence pseudolateral, -the lowermost bract is erect and seems to be a continuation of the stem- 6– 5 mm long, ovate, androgynous, with up to 8 female flowers at the base, and a terminal male part, 3.5– 2.5 mm long, with 3–5 flowers; lowermost bract 2.2– 1.7 cm long, 4– 3 mm wide at the middle part, embracing a utricle, sheathless, with a basal glumiform segment shorter than the inflorescence, 6.5– 3.3 mm long, brownish, with a wide central nerve, greenish to straw-colored when dry, apparently 3-nerved, continued into a linear lamina, flattish to slightly canaliculated, weakly antrorsely scabrid. Glumes brownish with a lighter middle longitudinal strip, the lowermost longer than the upper ones, ovate, acute, long-attenuated into a cuspidate apex, longest as lower is the glume; female glumes 4.5–2.5 × ~ 1.2 mm, deciduous, dropping before the utricles do; male glumes ~2.8–2.9 × 1 mm. Anthers ~ 0.9 mm long. Stigmas presumably 2 (not observed). Utricles 4–3 × 1.2– 1.1 mm, ovate, nerveless, smooth, with the lower half yellowish turning brownish towards the top, contracted at the base forming a 0.5– 0.3 mm. stipe, attenuated towards the apex into a 1.5– 1.2 mm beak, smooth, very shortly inconspicuously bidentate, Achenes 1.5 × 1.2 mm, ovate, biconvex, with the style leaving a 0.1 mm, ±conical, lignified remnant at the apex; rachilla linear in its entire length, shorter than the achene, ~1.2 × 1 mm, conspicuously antrorselyscabrid on its upper half.

Habitat and distribution:— Known only from the type collection, a population in the N slopes of the Cotopaxi volcano, in the central Ecuadorian Andes, at an altitude of 4100–4300 m. The habitat in the herbarium label says “páramo”, which refers to the Alpine tundra of the northern Andes. The appearance of the specimen, with the rhizomes covered of dry mud, seems to point to wet or moist soils. Given the tiny size of this species, it may have mostly been overlooked by collectors. Future findings in neighboring parts of the Andes may be expected.

Phenology:—Fruit were collected at the end of October.

Etymology:—The specific epithet “ via-incaica ” makes reference to the “Camino del Inca” (literally “Inca Trail”), a system of roads that extensively articulated the Tawantinsuyu (territories dominated by the Inca Empire), extending north to Colombia, and south to the central regions of Chile and Argentina. We chose this name because the closest species grows in the High Andes of central Chile and Argentina, thus giving a distribution pattern that resembles the way the Camino del Inca spread through the Andes.

Observations:— Carex via-incaica unequivocally belongs to the groups of species currently grouped in section Aciculares , which comprises seven species in South America (including C. via-incaica ) and four in Australia and New Zealand ( Global Carex Group, 2016). Wheeler (1989) also included in the section the South African C. killickii Nelmes (1955: 89) , but it has been demonstrated to be related to the species in the former genus Schoenoxiphium ( Global Carex Group, 2015). In its current delimitation, section Aciculares seems to be a paraphyletic group ( Global Carex Group, 2016), as it may include section Junciformes Kükenthal (1909: 82) , which would be the sectional name with priority, as well as C. camptoglochin V.I.Krecz (1937: 34) , a species endemic to South America ( Wheeler & Guaglianone, 2003).

Only other five unispicate species of Carex occur in northern South America, not including species previously placed in Uncinia , all them with androgynous spikes: C. camptoglochin ( Colombia, Ecuador), C. leptalea Wahlenberg (1803: 139 ; Venezuela), C. microglochin Wahlenberg (1803: 140 ; Ecuador), C. sanctae-marthae Mora-Osejo & Rangel (1983: 13 ; Colombia), and C. tachirensis Steyermark (1951: 68 ; Venezuela) (see Govaerts et al. 2015; Jiménez-Mejías et al. accepted). From these, C. sanctae-marthae and C. tachirensis may also have affinities to the species currently placed in section Aciculares . The following artificial key helps to distinguish the five unispicate Carex s.s. species from northern South America:

1. Rachilla long-protruding from the utricle beak, forming a hook at its tip ................................species previously placed in Uncinia

- Rachilla absent or shorter than the utricle (thus included in it), if longer, then it is straight and does not form a hook at the rachilla tip..................................................................................................................................................................................................... (2)

2. Rachilla longer than the utricle, protruding from the utricle beak; utricles deflexed when ripe..................................................... (3)

- Rachilla absent or shorter than the utricle, thus no protruding from the utricle beak; utricles ascending to somewhat patent when ripe................................................................................................................................................................................................... (4)

3. Female glumes as long as or longer than utricles; utricles 2–5 per spike ............................................................... C. camptoglochin

- Female glumes shorter than utricles; utricles 3–12 per spike..................................................................................... C. microglochin

4. At least the female glumes of the middle and distal parts of the spike much shorter than the utricles; utricles beakless or with a very short inconspicuous beak; lowermost bract shorter than the inflorescence ....................................................................... C. leptalea

- Glumes as long as or longer than the utricles; utricles attenuated at the top into a conspicuous beak; lowermost bract longer or shorter than the inflorescence.......................................................................................................................................................... (4)

5. Plants with long rhizomes; lowermost bract conspicuously much longer than the inflorescence ................................ C. via-incaica

- Plants densely caespitose; lowermost bract shorter to slightly longer than the inflorescence ........................................................ (5)

6. Lowermost bract glumiform, conspicuously much shorter than the inflorescence; spike broadly ovoid, ~ 6 mm wide...................... .............................................................................................................................................................................. C. sanctae-marthae

- Lowermost bract setaceous, slightly longer to a bit shorter than the inflorescence; spike lanceolate, up to 2 mm wide .................... ........................................................................................................................................................................................ C. tachirensis

Figures

FIGURE 1. Holotype of Carex via-incaica Jim.-Mejías & E.H.Roalson. A–B Whole specimens; arrow in B points to a long rhizome. C–D Inflorescences; arrow in C points to the lowermost bract, which is embracing a utricle; arrow in D points the terminal male flowers in a depauperate inflorescence. E Left, utricle, right, achene. Scale bar: 1 cm (A–B), 0.5 cm (C–D), 1 mm (E).