A synopsis of Christiana DC. (Malvaceae, Brownlowioideae), with a new species from the Brazilian Atlantic Forest Author Coutinho, Thales Silva 0000-0002-2173-4340 Instituto de Biociências, Laboratório de Estudos Integrados de Plantas (LEIP), Universidade Federal de Mato Grosso, Cuiabá, Mato Grosso, 78060 - 900, Brazil Author Barbosa-Silva, Rafael G. 0000-0002-0668-4840 Coordenacão Botânica, Museu Paraense Emílio Goeldi, Belém, Pará, 66077 - 830, Brazil & Institute of Systematic Botany, New York Botanical Garden, 2900 Southern Boulevard, Bronx, NY, 10458 - 5126, USA Author Dorr, Laurence J. 0000-0001-7157-363X Department of Botany, MRC- 166, National Museum of Natural History, Smithsonian Institution, P. O. Box 37012, Washington, D. C. 20013 - 7012, USA text PhytoKeys 2025 2025-02-28 253 33 56 journal article 308449 10.3897/phytokeys.253.145350 e7ab53c3-48ad-4923-b412-cb8adc950e3e 3. Christiana macrodon Toledo , Arq. Bot. Estad. São Paulo, n. s., f. m., 3: 29, pl. 8. 1952 [“ 1945 ”]. Fig. 2 Type. Brazil . São Paulo : Jardinópolis , mata à beira do Rio Pardo , 19 Nov 1947 (fl bud, fr), M. Kuhlmann 2009 ( lectotype , here designated: SP [ SP 001662 ; digital image!]; isolectotypes : HBG [ HBG-512735 ; digital image!], HBG [ HBG-512736 ; digital image!], MAC [ MAC 0055147 ]!, NY [ 01795748 ; digital image!], RB [ RB 553263 ; digital image!], SP [ SP 001663 ; digital image!]) . Description. Shrubs to trees, 1.5–3 m tall. Leaves: petioles 5–7 cm long, leaf blades 10–15 × 8–12 cm , widely ovate to circular, concolorous, bases cordate, margins coarsely dentate, apices acuminate, stellate trichomes above and below. Inflorescences short peduncled; flowers attached to peduncle. Capsules syncarpous, 1–1.2 cm long, transversely ellipsoid, wings absent. Distribution and habitat (Fig. 2 ). Endemic to Brazil , where it is found only in São Paulo state . This species occurs in Savanna and semi-deciduous seasonal forest (Atlantic Rainforest) at 530–600 m elevation. Phenology. Flowering specimens collected in November, and fruiting in April and September. Conservation status. Endangered ( EN ) ( Fernandes and Amorim 2018 ). Vernacular name. Algodoeiro. Etymology. From the Greek ‘ macr , macro ’ meaning ‘ long, large, great’, and ‘ odus , odon , odontos ’ meaning ‘ teeth’, the specific ephitet probably referring to the conspicuously dentate leaf blade margins. Additional specimens examined. Brazil . São Paulo : Adamantina, Estação Experimental do IAC, 05 Sep 1995 (fr), L. C. Bernacci et al. 1968 ( SPF [digital image]); Porto-Ferreira Reserv. Estad. Porto Ferreira, 17 Dec 1980 (fl bud), J. E. A. Bertoni 16889 ( RB [ RB 312587; digital image]); Gália, 15 Jun 2005 (st), M. R. Gorenstein 22202 ( ESA [digital image]); Ribeirão Preto, margem do Córrego Labareda, 11 Nov 2001 (fl bud), O. Kotchetkoff-Henriques & A. Furlan 623 ( ESA [digital image], IAC [digital image], SPFR [digital image]); Jardinópolis, margem do Rio Pardo, s. d. (st), M. Kuhlmann 2965 [= Herb. No. 50524] ( HAS [digital image], IAN [n. v.], SP [n. v.], US [00627713]); Matão, Fazenda Cambuhy, 14 Apr 1994 (fr), V. C. Souza et al. 5650 ( SP [n. v.], SPF [digital image], UNIP [digital image]). Discussion. Both Christiana macrodon and C. vescoana have dentate leaf blades, but the former species is distinguished by its coarsely dentate margins and fruits not winged (vs. finely dentate margins and fruits winged in the latter). The protologue states that the “ Typus ” is a collection (N. ° 43.987) in the herbarium at São Paulo ( SP ) but inasmuch as there now are two sheets with this number in that herbarium, one is designated here as the lectotype ( SP barcode SP 001662), as it has fruit.