Justicia carajensis F.A. Silva, A. Gil & Kameyama, 2019

Silva, Fabio Araújo Da, Gil, André Dos Santos Bragança & Kameyama, Cíntia, 2019, Justicia carajensis, a new species of Acanthaceae from the Serra dos Carajás, Pará, Brazil, Phytotaxa 388 (4), pp. 266-274 : 267-273

Justicia carajensis F.A. Silva, A. Gil & Kameyama , sp. nov. ( Figs.1–3 )

Type:— BRAZIL. Pará: Canaã dos Carajás, FLONA Carajás (Floresta Nacional de Carajás)—Subida para a FLONA Carajás, Serra do Tarzan , floresta, 6°25’19” S, 50°05’48” W, 1 September 2015, R. M. Harley, P. L. Viana, A. Gil, A. L. Ilkiu-Borges 57319 (holotype: MG!; isotypes: IAN!, SP!) .

Diagnosis: Justicia carajensis is similar to J. lythroides ( Nees 1847: 154) Graham (1988: 603) and J. goudotii Graham (1988: 603) in the secundiflorus inflorescence, corolla color pattern, size and shape of corolla lips; but differs by the erect branches (not decumbent branches), calyx with eglandular and glandular trichomes (not only eglandular trichomes or glabrous); ovary puberulous-glandular (not glabrous), and capsule puberulous with eglandular and glandular trichomes (not glabrescent).

Subshrub, 40–50 cm tall; stems erect, cylindrical, sulcate, geniculate, glabrous, sometimes with two vertical lines of pubescent indumentum. Leaves petiolate, petiole 5–13 mm long, blades 6.5–8 × 1.5–3.5 cm, slightly anisophylic, discolored, abaxially light green, lanceolate, elliptic to more rarely oblanceolate, apex acute, base attenuated to decurrent, glabrous on both surfaces, margin entire, not ciliate, cystoliths conspicuous, broquidodromous, 8–10 pairs of secondary veins. Spikes axillary and terminal, simple or composite, up to second order branches, secundiflorous, lax, rachis with two longitudinal lines of pubescent indumentum of eglandular trichomes; peduncle 0.3–0.5 cm long, rachises 3.5–5 cm long; bracts and bracteoles green, not imbricate, cystoliths prominent; sterile bract 3.5–4 × 0.3– 0.5 mm, narrow-triangular, sessile, apex acute, adaxially glabrous, abaxially puberulous, with eglandular trichomes, ciliate, bracteoles 2.5–3 × 0.2–0.3 mm, subulate, apex acute, adaxially glabrous, abaxially puberulous, with eglandular trichomes, ciliate; calyx green, 4-lobed, lobes equal, 4.5–6 × 0.3–0.5 mm, linear, apex acute, glabrous adaxially, puberulous abaxially, with eglandular and glandular trichomes, cystoliths prominent; corolla bilabiate, tube white, lips light purple with a white spot on palate area, 8–9.5 mm long, tube cylindrical and narrow, 5–5.5 mm long, upper lip 2.7–3 mm long, 2-lobed, lobes ca. 0.3 × 0.3 mm, lower lip 3.5–4 mm long, 3-lobed, lobes oblong, central lobe 1–1.2 × 0.8–0.9 mm, lateral lobes 0.8–0.9 × 0.8–0.9 mm; filaments white, inserted in apical third of the corolla, free portion of filaments 2–2.5 mm long, connective elongated, thecae yellow, superposed, upper thecae 0.3–0.5 mm long, appendix absent, lower thecae 0.2–0.3 mm long, appendiculate; pollen grain subprolate, ca. 34.5 × 26.0 μm, heterocolpate, 2-colporate, 4-pseudocolpate, 2 rows of areoles on a microreticulate tectum flanking the colporus, with a bireticulate continuum band in the mesocolpi area; ovary subcylindrical, puberulous-glandular, style 6–8 mm long, sparsely puberulous, stigma sub-capitate. Capsule 6–6.5 × ca. 1.5 mm, clavate, puberulous with eglandular and glandular trichomes. Seeds 4, sub-orbicular, ca. 1 mm diam., the entire surface tuberculate, glabrous.

Distribution and Habitat:—Up to the present, Justicia carajensis was found only in the municipality of Canaã dos Carajás, Pará State, Brazil ( Fig. 4 ), in Serra dos Carajás at Serra Sul and Serra do Tarzan. It grows along trails on partially shaded places in the forest, and it can also be rupicolous.

Preliminary Conservation Status:— Justicia carajensis has been collected only in Serra dos Carajás, with an extent of occurrence of approximately 272.8 km 2, and an area of occupancy of approximately 12 Km 2, in three localities. It grows in low forest on “canga” and in the typical Amazon rainforest. Although it is within a protected area, the “Floresta Nacional de Carajás”, the population that grows on “canga” is threatened by iron ore mining, and probably will have the habitat and area of occupancy reduced. Therefore, J. carajensis might be classified as endangered [EN B1ab(i,ii,iii)+B2ab (i,ii,iii)] according to IUCN Red list ( IUCN 2012).

Phenology:—Flowering and fruiting from August to September.

Etymology:—The specific epithet “ carajensis ” is a reference to the area of occurrence of the new species (Serra dos Carajás).

Taxonomic relationships:— Justicia carajensis shares with other species of Justicia sect. Chaetothylax ( Nees 1847: 153) Graham (1988: 602) or Chaetothylax clade ( Kiel et al. 2018) the bracts and bracteoles smaller than the calyx lobes, 4-lobed calyx, corolla with a narrow and relatively long tube, thecae inserted rather distantly on the filament and, frequently, the lower one smaller to completely reduced, and pollen type, i.e., 2-colporate, reticulate, with two rows of areoles flanking each side of the colporus ( Kiel et al. 2018). Justicia carajensis also presents another common feature of Chaetothylax clade, the secundiflorus spike. It is similar to J. lythroides ( Fig. 5A, B ) and J. goudotii ( Fig. 5 C, D ) (see Tab. 1), but differs from J. lythroides by filaments inserted at the upper third of the corolla (not filaments inserted at the central region of corolla); calyx lobes adaxially glabrous and abaxially puberulous with eglandular and glandular trichomes and conspicuous cystoliths (not puberulous), with homogenous texture (not hyaline margin); cylindrical corolla tube (not lower part of the tube cylindrical and upper part expanded; upper lip 2-lobed (not entire); both thecae fertile, the upper one without appendages, the lower one smaller and apendiculate ( Fig. 6A ) [not the lower thecae vestigial or completely absent ( Fig. 6B )]; and ovary puberulous with glandular trichomes (not ovary glabrescent); capsule puberulous with glandular trichomes (not capsule glabrescent); and from J. goudotii by filaments inserted at the upper third of the corolla (not filaments inserted at the central region of corolla); calyx lobes 4.5–6 mm long (not 7–10 mm long), adaxially glabrous and abaxially puberulous with eglandular and glandular trichomes and conspicuous cystoliths (not pubescent with only eglandular trichomes), corolla upper lip 2-lobed (not entire); both thecae fertile, the upper one without appendages, the lower one smaller and apendiculate ( Fig. 6A ) [not both thecae appendiculate, the lower one reduced and either sterile (in our observations) ( Fig. 6C ), although merely semi-sterile according to Ezcurra (2002), or fertile according to Graham (1988)]; and ovary puberulous with glandular trichomes (not ovary glabrescent); capsule puberulous with glandular trichomes (not capsule glabrescent).

Justicia carajensis is not sympatric with both J. lythroides and J. goudotii . Justicia lythroides occurs in semi-deciduous forests in southern and southeastern Brazil, in the states of Santa Catarina, Paraná, São Paulo, Rio de Janeiro, and Minas Gerais ( Flora do Brasil 2020 2018). Justicia goudotii is distributed along deciduous and semi-deciduous forests in Colombia, Bolivia, Central Brazil, Paraguay, and northern Argentina ( Ezcurra 2002).

Additional specimens examined (paratypes):— BRAZIL: Pará: Canaã dos Carajás, Flona de Carajás, estrada da S11 para a Serra Norte , 6 o 12’33”S, 50 o 18’58”W, 545 m elev., 12 August 2016, R. M. Harley et al. 57928 ( MG, IAN) ; Canaã dos Carajás, Floresta Nacional de Carajás : corpo C, 6°21’35”S, 50°22’35”W, 636 m elev., 1 September 2010, fl. e fr., T. E. Almeida et al. 2527 ( BHCB) ; Canaã dos Carajás, Serra dos Carajás, planta cultivada no MPEG, 11 August 2017, F. A. Silva & A. S. B. Gil 225 ( MG) .

Figures

FIGURE 1. Justicia carajensis. A. Habit. B. Flower with bract and bracteoles. C. Close-up of calyx showing eglandular and glandular trichomes. D. Spike rachis showing the sterile bracts. E. Fertile bract and bracteoles. F. Calyx. G. Corolla dissected. H. Stamen. I. Gynoecium. J. Ovary close-up showing glandular trichomes. K. Mature capsule. L. Close-up of capsule showing eglandular and glandular trichomes. M. Seed. Drawn by João Silveira based on R.M. Harley et al. 57319 (MG).

FIGURE 2. Justicia carajensis. A. Habit and inflorescences. B. Lateral view of the spike. C. Spike showing upper thecae of one flower. D. Lateral view of corolla lips showing the 2-lobed upper lip. (Photos by C. Hall).

FIGURE 3. Justicia carajensis pollen grains.A–E. Equatorial view.A. Optical section (LM). B. Endoaperture and ornamentation showing areoles (LM). C. Optical section showing 2 endoapertures (LM). D. Ornamentation (LM). E. Colporus in frontal view (SEM). F. Detail of the bireticulate ornamentation (SEM). R.M. Harley et al. 57319 (MG).

FIGURE 4. Distribution of Justicia carajensis.

FIGURE 5. Justicia species that resemble J. carajensis. A, B. J. lythroides. A. Upper part of the plant. B. Side view of inflorescence. C, D. J. goudotii. C. Inflorescence front view. D. Corolla front view. Photos by (A, B) M. Engels; (C, D) F.A. Silva.

FIGURE 6. Anther morphology of Justicia carajensis and similar species. A. J.carajensis. B. J. lythroides. C. J. goudotii.