Justicia triloba E. C. O. Chagas & Costa-Lima 2022, comb. nov.

Justicia triloba (Lindau 1914: 196) E.C.O.Chagas & Costa-Lima, comb. nov.

≡ Anisacanthus trilobus Lindau (1914: 196). Type:— BRAZIL. Piauí: Serra Branca, January 1907, E. Ule 7480 (holotype B† = F negative No. 8762!; lectotype K (K000529393)!, designated by Côrtes et al. (2010); isotypes G (G00236111)!, HBG (HBG522692)!, L (L2831415)!). (Figure 1A)

= Harpochilus trimerocalyx Rizzini (1948: 359). Type:— BRAZIL. Piauí: Serra do Brejo, July 1912, P. von Luetzelburg 1301 (holotype RB (RB00533887)!). (Figure 1B)

Distribution and habitat: — Justicia triloba is endemic to Brazil, occurring in the mountain ranges and plateaus from northeastern Brazil and its adjacencies, recorded along the Espinhaço Mountain Range (States of Bahia and Minas Gerais), Espigão Mestre (western State of Bahia and eastern State of Tocantins), Araripe (between the of States of Piauí, Ceará, and Pernambuco), and Ibiapaba (between the States of Piauí and Ceará) Plateaus (Chagas & Costa-Lima 2020a). Justicia triloba is a much-branched shrub, mainly inhabiting the dry scrubby vegetation, locally known as carrasco, but with some records in caatinga s.str., campo rupestre (within the Caatinga domain), and cerrado s.l. vegetation (Cerrado domain).

Selected additional specimens: — BRAZIL. Bahia: [Mun. Igaporã], 2 km E of Igaporã, on the BR 430 and about 44 km from Caetité, 13º46’S, 42º41’W, 14 April 1980 (fl), R. M. Harley et al. 21361 (CEPEC, IPA, K, MO, NY, RB, UEC, U, US). Ceará: Mun. Aiuaba, Gameleira de Baixo, 12 April 1991 (fl), M. A. Figueiredo et al. 116 (EAC). Minas Gerais: Mun. Buenópolis, Distrito de Curimataí, 17º55’7”S, 44º0’47”W, 22 January 2018 (fl), D. R. Gonzaga & W. A. Campanharo 1127 (RB). Pernambuco: Mun. Araripina, entre Feira Nova e Araripina, 6 May 1971 (fl), E.P. Heringer et al. 585 (IPA, RB, SPF, UB, US). Piauí: Mun. Padre Marcos, Serra Velha, km 2 da vicinal para Alagoinha do Piauí, 420 m, 21 May 1995 (fl, fr), M. E. Alencar 264 (HUEFS, K, US). Tocantins: Mun. Rio da Conceição, Folha SC-23-Y- C, T-5, área 7, ponto 18a, 649 m, 11º25’14”S, 46º44’20”W, 3 July 2009 (fl), F. C. A. Oliveira et al. 1500 (IBGE).

Notes: —The pollen morphology of Justicia triloba was discussed in detail by Côrtes et al. (2010), and the basic pattern of its pollen grains (i.e., 3-colporate + 6-syncolpate) is one of the variations of the pollen type found in the New World “justicioid” lineage. The same type of pollen morphology is illustrated by Rizzini (1948) for Harpochilus trimerocalyx, included by Côrtes et al. (2010) as a synonym of its basionym Anisacanthus trilobus. However, due to a floral morphology similar to the species of Thyrsacanthus from northeastern Brazil [e.g., Thyrsacanthus microphyllus Côrtes & Rapini in Côrtes et al. (2010: 967) and T. ramosissimus Moricand (1847: 165)] and pollen morphology congruent with the New Word “justicioid” lineage species, Côrtes et al. (2010) considered A. trilobus of uncertain generic position. Subsequently, based on molecular data, Côrtes et al. (2015) confirmed that A. trilobus is phylogenetically more related to the New World “justicioid” lineage, within Justicia Linnaeus (1753: 15) and closely related to Harpochilus Nees von Esenbeck (1847a: 146) species.

In addition, Justicia triloba shares with Justicia and related genera similar morphology of the capsules and seeds and some diagnostic characters, such as the presence of rugula in the corolla and anthers with asymmetric thecae. It is morphologically related to Justicia lepida (Moricand 1847: 157) Wasshausen (1973: 3), a species endemic to the Chapada Diamantina (and adjacent areas), in the State of Bahia, Brazil, occurring in campo rupestre vegetation (Côrtes & Rapini 2013, Chagas & Costa-Lima 2020b). Both species present branches with pubescent and glaucous indumentum, cymose dichasial inflorescences usually reduced to a single flower, a red corolla, calyx generally 3-partite, the lobes partially to fully fused, capsules with the fertile portion subglobose and irregularly striated longitudinally and seeds large, flat, and glabrous. Consequently, we propose its combination under Justicia.