Urtica mollis Steudel (1850: 258)

Weigend, Maximilian & Luebert, Federico, 2009, Weeding the nettles I: Clarifying species limits in perennial, rhizomatous Urtica (Urticaceae) from southern and central Chile and Argentina., Phytotaxa 2, pp. 1-12 : 10-11

3. Urtica mollis Steudel (1850: 258)

Lectotype (designate by Geltman, 1994: 23): [ Chile, Región V., de Valparaíso]: “ Urtica , vulgo Ortiga, flores monoici In ruderatis et sylvaticis ...(illegible)... Quillota", Bertero 1382 (P - P00585543!).Duplicates of lectotype (same label): BM!, G-DC!; duplicates of lectotype (different labels): “in ruderatis ad sepes udis Quillota Chili", October. 1829, Bertero 1382 (HUH!, M!, fragment: L!) . Syntypes: “In ruderatis, ad sepes, in udis Quillota", October 1829. Bertero 1383 (mixta cum U. leptophylla ) (P - P00585544!); “ Chili ", Bertero s.n. (P!). — Figs. 1C, H, I ; 4A, B .

Urtica diplotricha Philippi (1864: 234) . Holotype: [ Chile, IV Región, Prov. Choapa] “Concumen", January 1863, Landbeck s.n (SGO, fragment: HUH!).

Urtica buchtienii Ross (1905: 466) . syn. nov. Lectotype (here designated): [ Chile, Región V, Valparaíso, Prov. Los Andes,] " Uspallata Pass der chilenischen Hochkordillere (33˚ s. Breite ) zwischen Geröll ", 2200 m, 29.01.1903, O. Buchtien s.n.” (M!, isotypes: L!, M!, S, P!, E, G, US).

Urtica mollis is here reported from northern and central Chile and some parts of Argentina. U. mollis is readily recognised by its very dense, silky pubescence of relatively short hairs (ca. 0.15–0.20 mm), absent in all other South American species. However, this pubescence type is shared by the predominantly dioecious U. dioica L. subsp. pubescens (Ledeb.) Domin from southern and eastern Europe (Weigend 2005) and the monoecious U. dioica subsp. holosericea from North America ( Woodland 1982). In the absence of a critical revision of U. dioica s.l. we provisionally suggest retaining this taxon at species rank, but no differentiating characters are currently known between U. mollis and North American U. dioica subsp. holosericea . Future studies may show that the two taxa are synonymous. Figures 1E–I illustrates the differences in indument between U. magellanica and U. mollis . Urtica mollis is always very densely pubescent and the individual trichomes very short (ca. 0.15–0.20 mm), shorter than in the pubescent forms of U. magellanica (0.3–0.5 mm). Dwarfed specimens from high Andean regions, e.g., B. Sparre 11045 (CONC) and B. Sparre 10599 (CONC) with basal branching have been referred to U. buchtienii in the past ( Fig. 4A ). However, the dense indument and absence of other differentiating characters clearly indicate that they are just poorly developed individuals of U. mollis ( Fig. 4B ).

Representative specimens: ARGENTINA: Prov. Catamarca: Depto. Santa Maria, Los Trapiches , 25.04.1948, A. Reales 1377 ( MO) . Prov. Antofagasta de la Sierra, Cara , 3200 m, 10.02.1912, F.M. Rodriguez 313 (M). Depto. Ambato, El Rodeo, near Río Ambato , 1350 m, 15– 16.12.1971, L. Ariza 2638 ( MO) . Depto. Tafi, Tafi del Valle , 16.02.1958, H.A. Fabris 1550 (M). Prov. San Juan, Depto. Quebrada de las Vizcachas, Feb. 1960, H.A. Fabris & J.M. Marchionni 2348 (M). Prov. Mendoza, Depto. Malargue, 05.01.1893, F. Kurtz 7484 ( MO) . Depto. Malargue , 13.01.1885 F. Kurtz 5790 ( MO) . Depto. Malargue , 11.2.1893, F. Kurtz 7664 ( MO) . CHILE: III Región, Atacama: Prov. Huasco, Vallenar , 4000 m, Jan. 1924, E. Werdermann 266 (BM, E, MO) . IV Región, Coquimbo: Prov. Elqui, margin of Cerro Tapado , 3300 m, 30˚12´S, 70˚02´W, 07.01.1981, M. Kalin Arroyo 81901 ( CONC) . Prov. Elqui, Cerro Hipólito, Embalse La Laguna , 3300 m, 30˚16´S, 70˚03´W, 06.12.1979, C. Villagrán et al. 1827 ( CONC) ; Embalse La Laguna , 3350 m, 05.02.1963, Ricardi et al. 720 ( CONC) . Prov. Elqui, camino Internacional to San Juan, S side of Embalse La Laguna , entrance to Quebrada Calabozos , 3100 m, 06.01.1967, Ricardi et al. 1758 ( CONC) . Prov. Limarí, Depto. Ovalle, 190 m, 30 37 S, C. Jiles 7119 (M). Prov. Limarí , Cordillera de Ovalle , El Chape , 2650 m, 30˚43´S, 70˚38´W, 16.01.1949, C. Jiles 1206 (M). V Región, Valparaíso: Prov. San Felipe de Aconcagua , Catemu, 20.04.1989, O. Zöllner 11869 ( MO) . Región Metropolitana, Santiago: Prov. Cordillera , between Disputada and Pérez Caldera, 3000 m, 28.11.1954, B. Sparre 11045 ( CONC) . Prov. Cordillera, Pérez Caldera , 3000 m, 27.01.1954, B. Sparre 10599 ( CONC) . Prov. Chacabuco, Cuesta de La Dormida , 1160 m, Nov. 1956, H. Gunckel 29.962 ( CONC) . Prov. Santiago, Los Cerillos , 550 m, 20.12.1941, H. Gunckel 18.737 ( CONC) . sin loc.: Chili , Cuming s.n. ( BM) .

Figures

FIGURE 1. Flower, fruit and indument of Urtica: A, mature achene of U. dioica subsp. dioica (Henning & Schneider 313, B). B, mature achene of U. magellanica (Weigend 6078-C). C, nearly mature achene of U. mollis (Ricardi et al. 720). D, same, as enclosed in densely pubescent perianth (Ricardi et al. 720). E, sparsely pubescent adaxial leaf lamina of U. magellanica (Gunckel 46.420). F, sparsely pubescent adaxial leaf surface of U. magellanica (Riquelme 18). G, sparsely long-pubescent abaxial leaf surface of U. magellanica (Riquelme 18). H, densely pubescent adaxial leaf surface of U. mollis (Villagrán 1827). I, densely pubescent abaxial leaf surface of U. mollis (Villagrán 1827).

FIGURE 4. Urtica mollis Steud. and “U. buchtienii Ross”. A, high-alpine, juvenile plant (just beginning to flower) corresponding to the type of “U. buchtienii” (Sparre 17160). B, typical, unbranched form of of U. mollis corresponding to the type specimens (Arroyo 81901).