Justicia vitoriae I.H.F. Azevedo & A.K. Koch, 2025

Azevedo, Igor Henrique Freitas & Koch, Ana Kelly, 2025, Justicia vitoriae (Acanthaceae), a new species from the southern Amazon Forest, Brazil, Phytotaxa 711 (1), pp. 72-80 : 73-78

Justicia vitoriae I.H.F. Azevedo & A.K. Koch , sp. nov. ( Figs. 1–2 )

Type:— BRAZIL. Mato Grosso: Mun. Alta Floresta, “Reserva Surucuá”, 285 m elev., 9°52’38.93’’S, 56°05’54.09’’W, 29 June 2024, A. K. Koch et al. 1829 (holotype UFMT!, isotypes HERBAM!, RB!, SP!).

Diagnosis:— Justicia vitoriae is similar to J. riedeliana and J. matogrossensis , particularly in its dense capitate inflorescences, long bilabiate corollas, and robust capsules bearing spherical, smooth seeds. However, it can be distinguished from J. matogrossensis by its bracts exceeding 15 mm in length (vs. less than 9 mm), narrowly elliptic to lanceolate bracteoles (vs. linear), and corollas measuring 35 mm or more in length (vs. up to 20 mm). It differs from J. riedeliana in having bracts 6–12 mm wide that largely cover the calyx (vs. up to 6 mm wide, leaving the calyx exposed), bracteoles with rounded to obtuse apices (vs. acute), and a bilobed upper corolla lip (vs. entire).

Description: —Subshrubs to shrubs, 0.6–1.2 m tall, stems erect, rounded to obtuse-quadrangular, glabrous to pubescent or hirsute at young stems. Leaves petiolate; petiole 0.3–0.9 cm long, semicylindrical, glabrous to hirsute; blade 6.5–25 × 2.3–9.5 cm, narrowly elliptic to elliptic or lanceolate, base attenuate to decurrent, apex acuminate to cuspidate, margins slightly and irregularly crenate to repand, commonly ciliate, secondary veins 7–9, adaxially glabrous, abaxially glabrous to hirsute along veins, cystoliths 150–650 µm long, visible on both surfaces. Inflorescence terminal to axillary, capituliform, a compound dichasium, peduncle 2–3 cm long, partial-peduncles 1–3 mm long, subsequent peduncles gradually smaller, pubescent to hirsute; first pair of bracts highly variable, often intermediary between leaves and subsequent bracts, 14–20(54) × 6–12 mm, sessile, elliptic to narrowly elliptic or ovate to lanceolate, acute at apex, attenuate at base, green, margins entire, conspicuously ciliate, trichomes eglandular; subsequent bracts 16– 24(36) × 7–10 mm, sessile, elliptic to ovate or lanceolate, obtuse to acute at apex, acute at base, green, margins slightly repand, conspicuously ciliate, trichomes eglandular throughout and glandular at apex; bracteoles 10.5–15 × 3–4 mm, subsessile, narrowly elliptic to lanceolate, rounded to obtuse at apex, green, margins slightly repand, conspicuously ciliate, trichomes eglandular throughout and glandular at apex. Flowers sessile; calyx 5-lobed, 8–15 mm long, fused to ca. 1 mm at base, lobes equal, 7–14 × 1.5–2 mm, lanceolate, cuneate at apex, margins entire, conspicuously ciliate, trichomes eglandular throughout and glandular at apex; corolla bilabiate, 35–49 mm long, ventrally curved, deep pink to vinaceous on the tube, lighter pink on the lobes, externally pubescent, trichomes glandular and eglandular, internally hirsute at base, trichomes eglandular, basal tube 3–6 × 3–4.5 mm, expanded portion of the tube 24–36 × 5.5–8 mm, upper lip erect to slightly patent, 10–12 × 6–9 mm, bilobed, superior lobes ca. 1 × 1 mm, triangular, rounded at apex, lower lip patent, 9–13 × 13–30 mm, inferior lobe 7–9 × 7–9 mm, orbicular, emarginate at apex, lateral lobes 7–8 × 6–7 mm, elliptic, emarginate at apex; stamens 2, 11–14 mm long, filaments 9–12 mm long, slightly sigmoid, inserted at 23–28 mm in the corolla, glabrous, anthers subexserted, connivent, thecae highly asymmetrical, one ca. 1 mm below the other, proximally glandular-pubescent, the superior ca. 2 mm long, slightly mucronate at base, the inferior 2.5–3 mm long, strongly mucronate at base; gynoecium 3.8–4.0 cm long, white, nectar disc ca. 1 × 1.5 mm, ovary 2.5–3 × 1 mm, panduriform, pubescent, hirsute at apex, ovules 2 per locule, style pubescent at base, stigma bilobed, exserted, ventrally curved, lobes ca. 0.8 × 0.3 mm, elliptic. Capsules 12–17 × 4–6 × 4–6 mm, loculicidal, with hook-like retinacula, clavate to panduriform, puberulous, stipe 4–5 mm long; seeds 2–4 per fruit, spherical, 2.5 × 2–2.5 × 2 mm, glabrous, smooth.

Distribution:— Justicia vitoriae is endemic to the southern Amazon Forest, occurring in Mato Grosso and Pará, Brazil, reaching the Amazon-Cerrado transition zone ( Fig. 3 ).

Etymology:— The specific epithet honors Mrs. Vitoria Da Riva Carvalho, a pioneer in conservation and ecotourism initiatives in the Amazon region of Mato Grosso. She is the founder and president of the Cristalino Ecological Foundation, an institution dedicated to environmental education, protected area management, and the development of public policies. The Foundation has been a major supporter of research in the Cristalino region, funding over 60 projects that have led to the discovery of several new species, provided significant biodiversity data, and contributed to the creation of new public and private conservation areas in the state. The Foundation also owns the Surucuá Reserve and the Cristalino Private Natural Heritage Reserves, located in the municipalities of Alta Floresta and Novo Mundo, with a combined area of more than 7,000 ha.

Phenology:— The species has been collected in flower and fruit from May to August, during the regional dry season.

Ecology:— Justicia vitoriae occurs at elevations between 135 and 265 m in the understory of ombrophilous, seasonally semideciduous, and gallery forests, as well as in anthropized vegetation on moderately clayey soils. Although no floral visitors have been observed directly, the species’ floral morphology (including a large corolla with a long tube, vibrant coloration, and the spatial arrangement of anthers and stigma) strongly suggests pollination by hummingbirds. One collection near an urban area (A. K. Koch et al. 1829) included two species of Camponotus ( Mayr 1861: 10) ants and a species of fly (Brachycera) on the inflorescences, although their behavior was not recorded.

Conservation:— The extent of occurrence (EOO) is estimated at 112,551.901 km ² (corresponding to a Least Concern category), while the area of occupancy (AOO) is calculated at 64.000 km ² (corresponding to Endangered). Justicia vitoriae is currently known from 19 herbarium collections and seven iNaturalist observations, representing more than 10 distinct populations. Of the three collections from Pará, two are now lost due to flooding caused by the construction of the São Manoel hydroelectric plant on the São Manoel (Teles Pires) River. At least three populations occur within protected areas: Cristalino State Park, Cristalino Private Natural Heritage Reserves, and Xingu State Park. Additionally, the type locality, the Surucuá Reserve, is a private area in the process of being officially designated as a Private Natural Heritage Reserve. Other populations are primarily found along roadsides and in semi-urbanized areas. Therefore, based on IUCN criterion B and subcriteria B2b(i,ii,iii,iv), we suggest a conservation status of Near Threatened (NT) for J. vitoriae , as it does not currently meet the thresholds for a threatened category. However, it occurs within the so-called “Arc of Deforestation” in the southern Amazon, a region heavily impacted by illegal burning and deforestation.

Taxonomic comments:— Justicia vitoriae is best placed within Justicia sect. Simonisia ( Nees von Esenbeck 1847: 144) Graham (1988: 604) , characterized by its dense capitate inflorescences, long-tubed corollas, robust puberulous capsules, and spherical, smooth seeds. This section includes morphologically similar species such as J. carthagenensis , J. miguelii Graham (1988: 605) , J. riedeliana , J. simonisia , J. sprucei , and J. squarrosa Grisebach (1874: 226) . Kiel et al. (2018) recovered 12 species of this section in a strongly supported “core Simonisia ” clade, corroborating the taxonomic utility of the aforementioned morphological features. Although phylogenetic analyses may eventually refine its generic placement, the morphological evidence presented here supports the inclusion of J. vitoriae within the core Simonisia clade. Additionally, species such as J. matogrossensis and J. mcdadeana Silva et al. (2019: 703) , although not yet formally assigned to infrageneric groups, also share similar morphological traits and may belong to this clade.

Some species in this group differ by their elongated spike-like inflorescences and personate corollas, such as J. asclepiadea ( Nees von Esenbeck 1847: 144) Wasshausen & Ezcurra (1997: 172) , J. oncodes ( Lindau 1898: 48) Wasshausen & Ezcurra (1997: 175) , and J. rusbyi ( Lindau 1895: 491) Graham (1988: 605–606) , the latter showing an intermediate morphology with capitate inflorescences and a personate corolla. Nonetheless, all members of the core Simonisia clade share the distinctive feature of robust, puberulous capsules bearing spherical and smooth seeds, a rare trait within the genus.

Justicia vitoriae shows greatest morphological affinity with J. matogrossensis and J. riedeliana , and appears to represent an intermediate form both in morphology and geographic distribution. J. matogrossensis occurs in the eastern portion of the Amazon–Cerrado transition zone and differs in having linear bracteoles (vs. narrowly elliptic to lanceolate) and smaller corollas (up to 20 mm vs. ≥ 35 mm). In contrast, J. riedeliana , distributed further north in the Amazon Forest, has bracts up to 6 mm wide that leave the calyx exposed (vs. 6–12 mm wide, mostly covering the calyx), bracteoles with acute apices (vs. rounded to obtuse), and an entire upper corolla lip (vs. bilobed). J. vitoriae is further distinguished from other species by the calyx being largely covered by the bracts in both length and width. Additionally, it differs from J. carthagenensis in having narrowly elliptic to lanceolate bracteoles (vs. oblanceolate) and a longer corolla (≥ 35 mm vs. ≤ 30 mm) (see Table 1).

Additional specimens examined (Paratypes):— BRAZIL. Mato Grosso: Alta Floresta, Parque Zoobotânico, Terra Firme , 265 m elev., 9°51’52’’S, 56°04’24’’W, 6 June 2009, F. F. Cabral et al. 88 ( HERBAM) ; idem, 222 m elev., 9°51’51’’S, 56°04’31’’W, 27 June 2009, F. F. Cabral et al. 89 ( HERBAM) ; RPPN Cristalino, trilha Mirante da Serra 1, 260 m elev., 9°35’4.85’’S, 55°55’15.99’’W, 14 June 2023, A. K. Koch et al. 1257 ( HERBAM, RB, UFMT) ; idem, 28 June 2024, A. K. Koch et al. 1815 ( UFMT) ; Castanheira, Estrada Juara-Juruena, 71 km de Juara , 250 m elev., 10°51’59’’S, 57°46’35’’W, 22 June 1997, T. B. Cavalcanti 2371 ( CEN [photo]) ; Juruena, Estrada entre a cidade de Juruena e o Rio Juruena , ca. 2 km do Rio Juruena , 10°18’S, 58°23’W, 10 July 1997, V. C. Souza et al. 18719 ( ESA, SPF, UEC [photo], UFMT) ; idem, V. C. Souza et al. 18700 ( ESA) ; Nova Bandeirantes, Estrada de acesso a Nova Bandeirantes , 9°58’S, 57°28’W, 6 June 1997, N. M. Ivanauskas et al. 2050 ( ESA, UFMT) ; Novo Mundo, Parque Estadual Cristalino , s. d., G. S. Henicka 199 ( HERBAM) ; Santa Cruz do Xingu, Parque Estadual do Xingu, mata após o Rio Igarapé-Fontourinha , 9°48’04’’S, 52°28’24’’W, 10 June 2022, T. S. Coutinho et al. 476 ( UFMT) ; Parque Estadual do Xingu. Trilha de Monitoramento III - Projeto Monitora ICMBio, 9°53’11.23’’S, 52°30’32.82’’W, 7 June 2022, M. O. Córdova & M. Zappani 2443 ( CNMT) ; idem, 9°52’28.55’’S, 52°30’30.52’’W, 7 June 2022, M. O. Córdova & M. Zappani 2449 ( CNMT) ; Vila Rica, Fazenda Ipê, estrada para o Rio Beleza , 9°55’55’’W, 51°14’01’’W, 5 June 1997, F. R. Dário et al. 1221 ( ESA, SPF, UFMT) ; Municipality unknown, km-330 da Rod. BR-174, acapamento de Betomarco, Rio Tucunãzinho, 8 June 1979, M. G. Silva & C. Rosário 4819 ( INPA [photo], NY [photo]). Pará: Jacareacanga , UHE São Manoel – ME, 9°13’57’’S, 57°00’15’’W, 13 June 2016, J. Bruno 14 ( HERBAM) ; UHE São Manoel , 8 July 2016, J. A. M. Melo 111 ( HERBAM) ; Municipality unknown, Serra do Cachimbo, Sul do Estado do Pará, June 1955, M. Alvarenga s. n. ( RB) .

Figures

FIGURE 1. Illustration of Justicia vitoriae. A. Fertile branch. B. Inflorescence. C. First (basal) bract. D. Subsequent (distal) bract. E. Bracteole. F. Calyx. G. Glandular and eglandular trichomes on the apical portion of bracts, bracteoles, and calyx. H. Eglandular trichomes on the margins of bracts, bracteoles, and calyx. I. Open corolla showing androecium and gynoecium. J. Anther. K. Ovary. L. Ovary in longitudinal section. M. Stigma. N. Capsule. O. Seed. Illustrated by Igor Azevedo.

FIGURE 2. Photographic plate of Justicia vitoriae. A. Fertile branch. B. Stem node with leaves and axillary inflorescences. C. Leaf, adaxial surface. D. Leaf blade base. E. Leaf margin. F. Leaf, abaxial surface. G.Abaxial primary and secondary veins. H. Inflorescences. I. Dichasium with flowers and corresponding bracteoles. J. Anther, lateral view. K.Anthers, frontal view, connivent, with stigma positioned between them. L. Corolla, frontal view. M. Corolla, lateral view.N. Bilobed upper lip of the corolla.O. Eglandular and glandular trichomes on bracts, bracteoles, and calyx. P. Open capsule. Q. Seed. Photos by Ana Kelly Koch.

FIGURE 3. Geographic distribution of Justicia vitoriae in the southern Amazon Forest, encompassing the states of Mato Grosso and Pará, Brazil.