Synopsis of Sida (Malvoideae, Malvaceae) in the state of Rio Grande do Sul, Brazil Grings, Martin Boldrini, Ilsi Iob Phytotaxa 2022 2022-04-05 542 2 105 135 4X8G4 Linnaeus (1753: 683 - 684) Linnaeus 683 - 684 1753 [179,634,1634,1661] Magnoliopsida Malvaceae Sida Plantae Malvales 21 126 Tracheophyta species spinosa    Holotype:—“ Habitatin India” ( LINN 866.1! [digital image]).   Taxonomic notes:—  Sida spinosabelongs to section  Spinosae( Fryxell 1985)( Table 1). One of its striking features is the presence of a small projection, tubercle, such as a spine, but not sharp, in the base of petioles. This feature can also be found in  Sida riedelii, a very similar species, that is distinguished by the hyaline and crumbly dorsal face of its mericarps ( Schumann 1891, Krapovickas 2005), vs. mericarps with complete and reticulated dorsal face, which does not easily break ( Figures 11E–K, 14S). The species  Sida tuberculatacan also present a tubercle at the base of the petioles, which are generally smaller. However,  Sida tuberculata, has more than five mericarps.   Distribution, habitat and conservation status:—This species is pantropical, and also occurs in adjacent temperate zones ( Fryxell 1985, Fuertes Aguilar 1995, Brandão et al.2017). In Brazil  S. spinosaoccurs in northeast, southeast, midwest and south ( Bovini 2020) and in all regions of Rio Grande do Sul state( Figure 10), in ruderal environments and anthropized grasslands, except in Coastal grassland. The species is here considered Least Concern (LC) because it has large EOO and AOO, since it is a frequent and ruderal species, widely distributed.   Representative specimens:—  BRAZIL. Rio Grande do Sul. Augusto Pestana, Rosário,  19 February 1954,  J . Pivetta 879(ICN, PACA);  Barra do Quaraí, Parque Estadual do Espinilho, 30º11’22.5” S 57º29’46.5” W, 16 December2019,   M. Grings&   R. Paniz908( ICN); Boa Vista do Incra, Projeto de Assentamento28 de abril,  03 April 2009,   M. Grings2060( ICN); Caçapava do Sul, próximo a Pedra do Segredo,  23 November 2018,   M. Grings&   J. Schaefer1971( ICN); Derrubadas, Parque Estadual do Turvo,  December 1982, D.   B. Falkenberg302( FLOR); Gravataí, Cachoeirinha,  07 January 1949,   B. Rambos.n. ( PACA 39567); Uruguaiana, BR-  290, 154 m, WGS 84  S-29.86468º W -056.88529º,  03 December 2020, M. Grings et al. 2198(ICN). 3746876418 LINN India Habitat 10.11 21 126 LINN 866.1 1 holotype 3746876355 [538,1448,2025,2052] 1954-02-19 J Brazil Rosario Augusto Pestana 24 129 1 Rio Grande do Sul 3746876343 [434,1451,2061,2088] -30.189583 Barra do Quarai 1 -57.49625 Parque Estadual do Espinilho 24 129 1 3746876326 [207,323,159,185] M Grings 25 130 1 3746876312 [361,1409,158,185] 2009-04-03 R, ICN Projeto de Assentamento Paniz Boa Vista do Incra 25 130 1 3746876469 2018-11-23 M, ICN Pedra do Segredo Grings Cacapava do Sul 25 130 1 3746876367 [1118,1232,195,221] M Grings 25 130 1 3746876324 1982-12 J, ICN Parque Estadual do Turvo Schaefer Derrubadas 25 130 1 3746876304 1949-01-07 B, FLOR Cachoeirinha Falkenberg Gravatai 25 130 1 3746876368 [336,1114,266,293] B 290154 Rambo Uruguaiana 25 130 PACA 39567 1 3746876389 2020-12-03 S -29.86468 25 130 1