taxonID	type	description	language	source
A3D2ADA0428A5638B32E03424E51EB90.taxon	description	Figs 1, 2 A – E, 3 A – C	en	Silva, Fabio Araújo da, Kameyama, Cíntia, Vitta, Fabio A., Buzato, Silvana, Zappi, Daniela C. (2025): A forgotten gem: Mendoncia affinis (Acanthaceae), a new species once thriving at the Avenida Paulista, São Paulo, Brazil. PhytoKeys 260: 1-11, DOI: 10.3897/phytokeys.260.153687
A3D2ADA0428A5638B32E03424E51EB90.taxon	diagnosis	Diagnosis. Mendoncia affinis differs from M. velloziana by the combination of subquadrangular to quadrangular, hollow, sulcate, tomentose-velutinous branches (vs. subcylindrical to subquadrangular, solid, sulcate, densely pubescent branches); petioles and pedicels with tomentose to densely pubescent indumentum, with adpressed to semi-erect eglandular hairs (vs. tomentose with adpressed eglandular hairs); bracteoles ovate to deltoid, golden-greenish (in vivo), 2 – 2.7 × 1 – 1.5 cm, glabrous internally (vs. ovate-lanceolate, red (in vivo), 2.4 – 3.3 × 1 – 1.6 cm, sparsely lepidote internally); leaf venation brochidodromous with 3 – 4 pairs of secondary veins (vs. eucamptodromous with 3 – 5 pairs); ovary densely pubescent to tomentose (vs. lepidote with glandular-peltate trichomes); style basally pilose and glabrous distally (vs. entirely glabrous); and oblongoid, pubescent drupes (vs. ellipsoid, glabrous drupes).	en	Silva, Fabio Araújo da, Kameyama, Cíntia, Vitta, Fabio A., Buzato, Silvana, Zappi, Daniela C. (2025): A forgotten gem: Mendoncia affinis (Acanthaceae), a new species once thriving at the Avenida Paulista, São Paulo, Brazil. PhytoKeys 260: 1-11, DOI: 10.3897/phytokeys.260.153687
A3D2ADA0428A5638B32E03424E51EB90.taxon	description	Description. Herbaceous climbers, stems subquadrangular to quadrangular, fistulose, longitudinally sulcate when young, tomentose-velutinous to glabrescent, eglandular trichomes adpressed, golden, internodes 4.5 – 11.5 cm long. Leaves membranaceous; petiole 5 – 12 mm long, slightly canaliculated, tomentose to densely pubescent, eglandular trichomes adpressed to semi-erect; leaf-blade 5 – 10.5 × 2.5 – 5.3 cm, ovate-lanceolate to elliptic, base obtuse to cuneate, margin entire, apex acuminate to cuspidate, with mucro 0.9 – 1 mm long; venation brochidodromous, 3 – 4 pairs of secondary veins, midrib and secondary veins prominent, densely covered in eglandular trichomes; adaxial face smooth, glabrescent to sparsely strigose, eglandular trichomes semi-erect, abaxial side tomentose-velutinous, eglandular trichomes semi-erect to erect. Flowers 1 – 3 (– 4) per axil; pedicels 19 – 50 mm long, densely tomentose-velutinous, trichomes eglandular, adpressed to semi-erect; bracteoles 2 – 2.7 × 1 – 1.5 cm, golden-greenish (in vivo), ovate to deltoid, fused up to the apical third, subcoriaceous, midvein slightly prominent, base cuneate to truncate, apex mucronate, with mucro 1.2 – 1.8 mm long, externally densely pubescent to velutinous, eglandular trichomes semi-erect, brown (ex vivo), 0.8 – 1.2 mm long, internally glabrous; calyx 1.2 – 1.5 × 3 – 3.2 mm, entire, slightly dentate at margin, glabrous; corolla red, 2.5 – 2.7 cm long, tubular, tube slightly curved, externally glabrous, sparsely glandular-papillose within, base of tube 0.7 – 0.9 cm wide, middle of tube 0.6 – 0.7 cm wide, apex of tube 0.9 – 1 cm wide, 5 lobes 0.29 – 0.3 × 0.18 – 0.2 cm, oblong, emarginate, all lobes reflexed; free part of filaments 2 – 2.5 mm long, dorsal anthers with thecae 0.85 – 0.9 cm long, ventral anthers with thecae 1 – 1.2 cm long; ovary 2.4 – 3 × 2 – 2.2 mm, densely pubescent to tomentose, eglandular trichomes erect; style 2 – 2.2 cm long, proximally pilose, distally glabrous, eglandular trichomes erect, stigma bilobed, lobes subequal, 0.5 – 0.6 mm long. Drupe (immature) 1.1 – 1.2 × 0.9 – 1 cm, oblongoid, pubescent, with erect to semi-erect eglandular trichomes.	en	Silva, Fabio Araújo da, Kameyama, Cíntia, Vitta, Fabio A., Buzato, Silvana, Zappi, Daniela C. (2025): A forgotten gem: Mendoncia affinis (Acanthaceae), a new species once thriving at the Avenida Paulista, São Paulo, Brazil. PhytoKeys 260: 1-11, DOI: 10.3897/phytokeys.260.153687
A3D2ADA0428A5638B32E03424E51EB90.taxon	etymology	Etymology. The specific epithet affinis refers to the morphological similarity between the new species and Mendoncia velloziana. This similarity led to a taxonomic confusion, where specimens of M. affinis were often mistakenly identified as M. velloziana, causing M. affinis to remain hidden under that name for a long time.	en	Silva, Fabio Araújo da, Kameyama, Cíntia, Vitta, Fabio A., Buzato, Silvana, Zappi, Daniela C. (2025): A forgotten gem: Mendoncia affinis (Acanthaceae), a new species once thriving at the Avenida Paulista, São Paulo, Brazil. PhytoKeys 260: 1-11, DOI: 10.3897/phytokeys.260.153687
A3D2ADA0428A5638B32E03424E51EB90.taxon	distribution	Distribution and habitat. Mendoncia affinis occurs in Brazil and Paraguay, with a broad distribution across the semideciduous seasonal forests (mata de planalto) (Capobianco 2001) that extend from Southeastern and Southern Brazil into the bordering region of Paraguay. The species has been recorded in the Brazilian states of Minas Gerais, Rio de Janeiro, São Paulo, Paraná, Santa Catarina and Mato Grosso do Sul, and in the Department of Amambay in Paraguay (Fig. 4).	en	Silva, Fabio Araújo da, Kameyama, Cíntia, Vitta, Fabio A., Buzato, Silvana, Zappi, Daniela C. (2025): A forgotten gem: Mendoncia affinis (Acanthaceae), a new species once thriving at the Avenida Paulista, São Paulo, Brazil. PhytoKeys 260: 1-11, DOI: 10.3897/phytokeys.260.153687
