Paronychia ubinensis Montesinos, 2013

Montesinos Tubée, Daniel B., 2013, Paronychia ubinensis (Caryophyllaceae: Paronychioideae) a new species from Moquegua, South Peru, Phytotaxa 124 (1), pp. 50-54 : 50-52

Paronychia ubinensis Montesinos , spec. nov.

TYPE:— PERU. Moquegua Department: General Sánchez Cerro Province, Ubinas District : Punku near Tassa locality, 16°10’30’’ S, 70°42’21’’ W. 4030 m, 6 April 2012, Montesinos 3698 (holotype WAG!, isotype USM).

Additional specimens examined: PERU, Moquegua Department, General Sánchez Cerro Province, Ubinas District : Roadside , Querala-Patune , 4340 m, 1 June 2011, Montesinos 3164 ( USM) . PERU, Moquegua Department, General Sánchez Cerro Province, Yunga District : Sura slopes, 4500 m, 28 March 2013, Montesinos 4049 ( USM, CUZ, HSP) .

Herba perennis, 2–4 cm longa, folia relinquit subterminale glomerulus; bracteae oblongae ovatis; petalis obscure viridis colorem.

Perennial herb with stem woody and branched at the base, decumbent, caespitose, densely congested and imbricate, forming pulvinate tufts, 2–4 cm long, with internodes <0.5 mm long. Leaves disposed in subterminal glomerules. Leaves brown red to lilac red, stiff, linear to narrowly elliptic, 1.8–2.4 mm x 0.6–0.9 mm, apex acute, with translucid, 0.1–0.2 mm stout mucro (brown at the base) with few minute bristle hairs at the tip; margin glabrous and slightly folded, the base of the leaves deep red or pale purple, always darker than the lamina; stipules oblong-lanceolate, 1.8–2.2 mm x 0.6–1.0 mm, mostly equalling the leaves, tip aristate to acuminate, margin and tip with few minute bristle hairs, midrib with more bristle hairs than the lamina. Leaves subglabrous, with few minute hirtella on the mucro. Bracts oblong-ovate, 1.2–2.0 mm x 0.8–1.5 mm, slightly obtuse, with minute hirtella on margins and tip. Flowers few, 1.9–2.2 mm x 0.9–1.2 mm, glabrous and urceolate; receptacle ovoid, whitish, 0.8–1 mm x 0.6–0.8 mm; sepals ovate, white, scarious, 1.6–1.8 mm x 0.8–1.4 mm, margins with <0.1 mm long white bristle hairs; petals dark red to purple, concave, 0.2–0.4 mm x 0.1–0.2 mm, urceolate, glabrous, base pale green; filaments 0.1-0.3 mm long; anthers 0.1–0.2 mm x 0.05–0.1 mm and pale green; ovary oblong, pale white, 0.6–0.8 x 0.6–0.8 mm; style <0.1 mm long, stigma indistinctive. Fruit oblong-ovoid, 1-1.2 mm long, smooth, pale brown; seed c. 0.8-1 mm, subglobose to ovoid.

Ecology and distribution: Paronychia ubinensis grows mostly on rocky slopes and plateaus with bare soils and is associated with chasmophyte vegetation. The plant was found at elevations of 4030–4500 m. This species is endemic to Peru and is known thus far only from two collections from Moquegua.

Comparison: Paronychia ubinensis is closely related to the Andean Paronychia complex ( Chaudhri 1968, MacBride 1937, Alvarez 2010, Kool 2012). The geographical parameters and habitats of Paronychia andina A.Gray , P. mandoniana Rohrb. , P. muschlerii Chaudhri , P. peruviana Chaudhri and P. weberbaueri Chaudhri are similar to the newly described species. However, these species differ in morphological characteristics, including leaves, flowers and ovary. Numerous herbarium specimens were examined from USM, HUSA, MO, F, WAG and L. None of the described Andean species of Paronychia has internodes shorter than 0.5 mm, the leaf shape linear to narrowly elliptic and size shorter than 2.2 mm, the sepals larger than 1.6 mm and the ovary not larger than 0.8 mm, all characters in P. ubinensis . Therefore, P. ubinensis has the shortest leaf size and larger ovary size of any known Andean Paronychia species. Another important parameter is the absence of pubescence and bristle hairs on the leaves of P. ubinensis . Trichomes are only present on the mucro; as opposed to the related Paronychia species , where pubescence in leaves and leaf indument is common.

Paronychia ubinensis was also compared with the Paronychia species occurring in the Bolivian and Chilean Andes, with which significant morphological and geographical differences were found. For instance, P. communis Cambess. (Cabessèdes 1829) , P. chilensis DC. ( Candolle 1828) , P. johnstonii Chaudhrii ( Chaudhri 1968) and P. setigera (Gillies) F. Herm ( Hermann 1937) have larger leaf size (> 5 mm) and longitudinal separation of the glomerules (> 1 cm), and form more prostrate plants inhabiting disturbed areas in lower elevation regions. P. hieronymi Pax ( Pax 1894) forms dense woody stems, its leaf size is larger and has a pubescent surface, and it is restricted to Bolivia and Argentina. P. microphylla Phil. ( Philippi 1891) is characterized by a shrubby habit with larger leaf size and forms dense green glomerules, with a flower size larger than 4 mm. Therefore, Paronychia ubinensis can be classified as one of the smallest species from the Andean group.

According to Alvarez (2010), the genus Paronychia is polyphyletic and Paronychia andina and Paronychia weberbaueri form a clade. It is unlikely that the Andean Paronychia species form a monophyletic group (pers. comm. Anneleen Kool).

Etymology: The specific epithet of the new species refers to the endemism in the Ubinas district, in the Moquegua department, southern Peru.