3. Sida confusa Hassler (1910b: 119) (Figures 1M–Q, 2, 14B).

Lectotype (designated by Rodrigo 1944: t. 15):— PARAGUAY. “In altoplanitie Yeruti”, Hassler 5768 (NY barcode 00222025! [digital image]; isolectotypes P barcode 02285390! [digital image], S-R-11248! [digital image], UC barcode 941239! [digital image], MO barcode 1574099! [digital image]).

= Sida krapovickasii H.A. Keller (2021: 2) . Syn. nov. Holotype:— ARGENTINA. Corrientes. Dep. Santo Tomé, San Alonso, Establecimiento Timbauva, 27°59’36,78”S, 55°55’19,47”W, 101 m, 08 January 2021, H. A. Keller & J. L. Rojas 14386 (CTES).

Taxonomic notes: —The species was never included in any section in the studies in which it was treated, before Keller (2021) (Hassler 1910b, Rodrigo 1944, Monteiro-Filho 1936, 1942). Fuertes Aguilar (1995) comments that the species Sida abutilifolia Miller (1768: Sida no. 12, as “abutifolia”), section Spinosae, has two related species in Argentina and Brazil, Sida argentina K.Schum (1891: 315) and S. confusa . According to Fuertes Aguilar (1995), in the present work, the species S. confusa was included in the section Spinosae . Fryxell (1985) pointed out the characters that define section Spinosae (Table 1), which we observed in S. confusa: cordate leaf blades, dentate to the base, apex acute to rounded; five mericarps, flowers in leaf axils, and calyx lobes not bi-colored, uniformly colored. Although Keller (2021) includes S. krapovickasii in the section Nelavagae, we maintain the view mentioned above, keeping S. confusa in the section Spinosae (Table 1). The species of section Nelavagae have acuminate leaves, feature not present in the species. Sida confusa is distinguished from the other species from Rio Grande do Sul by its prostrate habit; leaf blades ovate to suborbicular, crenate-serrate; stems, petioles and peduncles with long simple trichomes (ca. 2 mm long) and with short stellate and glandular trichomes (ca. 0.1–0.2 mm long); petals white or light yellow with dark yellow basal spot; mericarps muticous (Figures 1M–Q, 14B). Keller (2021) published the species Sida krapovickasii, synonymized here for the first time. All the characters presented by the author for S. krapovickasii, muticous mericarps, prostrate herbs, indument, leaf and flower morphology, confer with S. confusa, a previously published species. For these reasons the species is here synonymized. Although Rodrigo (1944) considers that the mericarps of S. confusa are indehiscent, we observe that they are dehiscent at the apex, as also observed by Keller (2021).

Distribution, habitat, and conservation satus: — Sida confusa occurs in Paraguay (Caaguazú and Concepción), northeast Argentina (Corrientes and Misiones) and Brazil (Santa Catarina and Rio Grande do Sul). In Rio Grande do Sul the species occurs in Highland grassland and in Aristida grassland (Figure 2), usually in rocky grasslands, with the presence of shrubs. The species presents an EOO of 159,265.052 Km² and an AOO of 36 Km². Therefore, due to its AOO and its habitat is being increasingly fragmented due to the growth of crops (Andrade et al. 2015), the species is here considered EN (Endangered), under IUCN (2017) criterion B2abiii.

Representative specimens: — BRAZIL. Rio Grande do Sul. Augusto Pestana, Boca da Picada, 16 February 1956, J . Pivetta s.n. (HRCB 44476); Giruá, Granja Sodal, 14 February 1966, K . Hagelund 4090 (CTES, HAS); Muitos Capões, Ituim, Granja Bela Vista, 641 m, 28º24’01”S 51º20’39”W, 08 February 2012, M . Verdi & B. O . Boeni 6146 (FURB); WGS 84 S 28.53293 º W 051.37276º, 11 March 2021, M . Grings 2247 (ICN) . Santa Catarina, Capinzal, Morro em frente ao Hotel São Cristóvão, 715 m, 27º22’20”S 51º35’23”W, 28 November 2018 A . Kassner-Filho 4107 (FURB) .