A new polyploid species of Mecardonia (Gratioleae, Plantaginaceae) from South America Author Greppi, Julián A. Instituto de Floricultura, Instituto Nacional de Tecnología Agropecuaria, De los Reseros y Las Cabañas s / nº, Hurlingham 1686, Buenos Aires. Argentina. Author Sosa, María De Las Mercedes Instituto de Botánica del Nordeste (UNNE-CONICET), Casilla de Correo 209, W 3400 CBL Corrientes, Argentina. & Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Av. Libertad 5460, 3400, Corrientes, Argentina. Author Dematteis, Massimiliano Instituto de Botánica del Nordeste (UNNE-CONICET), Casilla de Correo 209, W 3400 CBL Corrientes, Argentina. & Facultad de Ciencias Exactas y Naturales y Agrimensura, Universidad Nacional del Nordeste, Av. Libertad 5460, 3400, Corrientes, Argentina. text Phytotaxa 2017 2017-04-13 303 3 264 270 http://dx.doi.org/10.11646/phytotaxa.303.3.6 journal article 10.11646/phytotaxa.303.3.6 1179-3163 13690553 Mecardonia reneeae Greppi & Sosa , sp. nov. ( Figs. 1–2 , Table 1 ) Type:― ARGENTINA . Corrientes . Dep. Empedrado, Ruta Provincial 6 y arroyo Empedrado [ 27° 48’S , 58°30’W ], 20 December 2005 . Greppi & Hagiwara 560 ( holotype BAB !, isotype SI !). Diagnosis :― A Mecardonia procumbens var. flagellaris similis, sed habitu terophyto, caulibus erectis, radicibus gemmiferis, foliis serratis, petalis angustis, deltoideis et linearibus, fructus minore, chromosomatum numero tetraploideo 2n=44 (contra 2n=22). Terophyte, 15–17(–20) cm high. Roots gemiferous. Stems erect, quadrangular, glabrous, 1 mm diam., internodes 5–20 mm long. Leaves opposite, sessile, narrowly elliptic, 6–16(–20) × 2–5(–6) mm, margin serrate, base attenuate. Bracteoles 3–7 × 0.5–1.5 mm , linear, margin entire to denticulate. Pedicels 10–35(–40) mm long, erect, flexuous. Flowers one or two per node, 10–16 mm long, yellow with chestnut streaks in the throat. Calyx 5–7 mm long; sepals narrowly deltoid to linear, acute, dorsal sepal 5–7(–10) × 1–1.2 mm ; two ventral sepals 5.5–7(–8) × 0.8–1(–3) mm; two lateral sepals 4–6(–8) × 0.3–0.6 mm . Corolla 8–14 × 6–8 mm , posterior lip 6–8 × 6–7 mm , entire, briefly apiculate, internally pubescent at base; middle lobe of frontal lip 6–7 × 7–8.5 mm ; broadly obovate, glabrous; lateral lobes of equal size, sometimes obovate. Stamens 4, anterior filaments 5 mm long, posterior 4 mm long, all inserted at the base and reaching half of the corolla tube length. Ovary ellipsoid, 3 mm long; style 3–4 mm long. Capsule ellipsoid, light brown, 3–5 × 1.5–1.8 mm . Seeds, 0.4–0.5 × 0.3–0.4 mm , rough, blackish. Distribution, habitat and phenology:— Mecardonia reneeae grows in open and humid areas, low clayey loam soils near watercourses, or border of streams in eastern Formosa , Chaco , northwest of Corrientes and northeast of Santa Fe in Argentina , within the Chaco phytogeographic province ( Cabrera 1976 ). The species flowers from August to March. Etymology :— The specific epithet is dedicated to Renée H. Fortunato, Argentinean botanist dedicated to the study of Leguminosae. Additional specimens examined : ─ARGENTINA . Prov. Chaco : Dep. Bermejo , Las Palmas , 14 November 1983 , Fortunato et al. 607 ( BAB ) ; Dep. Primero de Mayo , Colonia Benítez , 10 June 1959 , Schulz 10437 ( BAB ). Prov. Corrientes : Dep. Capital, near to Ingenio Primer Correntino, 18 Km NE of Corrientes , 15 September 1982 , Schinini & Martínez-Crovetto 2636 ( CTES ) ; 5 Km E of Laguna Brava , 29 August 1970 , Krapovickas & Cristóbal 15836 ( CTES ) ; 10 Km E of Laguna Brava , route 5, 21 August 1970 , Krapovickas & Cristóbal 16099 ( CTES ) ; Parques de la Facultad de Ciencias Agrarias , 23 August 1974 , Quarín 2403 ( CTES ) ; Molina Punta , November 1978 , Arbo 1562 ( CTES ) ; Perichón , 8 September 1975 , Schinini 11601 ( CTES ) ; Dep. San Cosme , Paso de la Patria , 12 August 1967 , Krapovickas & Cristóbal 1302 ( CTES ) ; Desvío a Pto. González , 9 Km. near to Paso de la Patria , 10 September 1971 , Tressens et al. 168 ( CTES ) ; Dep. San Luis del Palmar , 10 Km SE of San Luis del Palmar , Route 6, 26 September 1973 , Quarín & Tressens 1349 ( CTES ). Prov. Formosa : Dep. Pilcomayo, Parque Nacional Pilcomayo, near to Puerto Soledad, 9 November 1991 , Fortunato et al. 2097 ( BAB , SI ). Prov. Santa Fe : Dep. Gral. Obligado, Villa Ana, 18 August 1973 , Quarín 1193 ( CTES ) .