Justicia oppositiflora R. Villanueva & J. R. I. Wood, 2025

Villanueva-Espinoza, Rosa, Deng, Yunfei, Scotland, Robert & Wood, John R. I., 2025, Preliminary notes on Justicia (Acanthaceae) in Peru, PhytoKeys 258, pp. 1-123 : 1-123

publication ID	https://doi.org/10.3897/phytokeys.258.144435
DOI	https://doi.org/10.5281/zenodo.15676451
persistent identifier	https://treatment.plazi.org/id/94171130-DD48-5842-9793-7E088CB17CB9
treatment provided by	PhytoKeys by Pensoft
scientific name	Justicia oppositiflora R. Villanueva & J. R. I. Wood
status	sp. nov.

Treatment

6. Justicia oppositiflora R. Villanueva & J. R. I. Wood sp. nov.

Type.

Peru • Pasco, Prov. Oxapampa, Dist. Huancabamba, Río Yanachaga drainage, Hac. Yanachaga , 10°32'S, 75°32'W, 2240–2260 m, 26 May 1983, D. N. Smith & G. Pretel 4189 (holotype MO-3507877 , isotypes F-1992314 , US-3123730 , USM) GoogleMaps .

Diagnosis.

This species is closely related to Justicia pozuzoensis but the flowers are arranged in opposite pairs (not solitary), the calyx lobes 6–8 (– 11) mm (not 12–15 mm) long and the corolla 3.2–3.9 cm long (not 4–4.9 cm) long. It also bears a close resemblance to J. novagranatensis Leonard in having somewhat lax elongate spikes of opposite flowers with similar floral dimensions but differs in the very shallowly lobed lower corolla lip (not deeply lobed to 7 mm).

Description.

Subshrub to 1.5 m (– 5 m) in height; stems ± glabrous, occasionally obscurely bifariously hirtellous below nodes, sometimes caniculate. Leaves shortly petiolate; lamina 3.5–12 × 0.8–3 cm, lanceolate to narrowly oblong-elliptic, apex acuminate to a fine point, base cuneate, sometimes slightly oblique, margin entire to obscurely undulate, both surfaces glabrous or obscurely hirtellous on the midvein near the base, adaxially with cystoliths, abaxially paler, gland-dotted, venation not prominent, lateral veins c. 6–7; petioles 2–4 mm, deeply channelled, glabrous. Inflorescence of lax spikes, both terminal and from the upper leaf axils; flowers in distant opposite pairs, up to 2 cm apart below, but closer above; spikes 5–9 cm long; rhachis glabrous to obscurely bifariously hirtellous; floral bracts 4–5 × 1–1.5 mm, ovate-deltoid, acuminate, glabrous to shortly puberulent and with prominent cystoliths; bracteoles lanceolate-deltoid 5–6 × 1 mm, glabrous to shortly puberulent; calyx subequally 4 - lobed, lobes lanceolate, finely acuminate, 6 × 0.75 mm at anthesis but reaching 11 × 1.25 mm in fruit, pubescent; corolla 3.2–3.9 cm long, red, glabrous, 2 - lipped, tube 1.8–2.2 cm long, gradually widened from a narrow base, c. 1.5 mm wide, to 4–5 mm at mouth, strongly 2 - lipped, upper lip bifid, 1.5–2 cm long, lower lip slightly shorter, shallowly 3 - lobed, lobes subequal, ovate, rounded c. 1 × 1 mm; filaments glabrous, white, c. 2.2 cm long, anther thecae superposed, glabrous, 1.25–1.5 × 0.5 mm, both with a basal appendage; pollen prolate, 47–57 × 25 μm, 2 - aperturate, colporate, 1 row of c. 7–10 insulae and 1 row of peninsulae (Fig. 48 D View Figure 48 ); style c. 4 cm long, glabrous; ovary c. 2 mm high, conical, glabrous. Capsule 15.3 mm long, glabrous, clavate, 4 - seeded; seeds 2 mm long.

Illustration.

Fig. 8 View Figure 8 .

Etymology.

The epithet “ oppositiflora ” refers to the arrangement of the flowers in the inflorescence, the opposite flowers being an important distinction from Justicia pozuzoensis .

Phenology.

Found in flower in January and May to August.

Habitat.

Primary and secondary forest. 2100–2250 m.

Distribution.

Apparently endemic to the Yanachaga-Chemillén National Park in Peru. Fig. 55 View Figure 55 .

Material examined.

Peru • Sine loc. McLean s. n. (K). Pasco: Prov. Oxapampa , the type collection ; • ibid., P. N. Yanachaga-Chemillén, Sector Quebrada Yanachaga, 10°24'13"S, 75°29'04"W, 2200 m, 14 Jan. 2005, R. Vásquez et al. 30641 ( MO) GoogleMaps ; • ibid., Sector Palcazú – Alto Navarra, 10 ° 16 ’ ' S, 75°15'W, 2100 m, 24 Aug. 2005, R. Rojas 3846 ( HOXA, MO, US) GoogleMaps ; • ibid., P. N. Yanachaga-Chemillén, Quebrada Yanachaga, 10°24'44"S, 75°28'56"W, 2250 m, 14 June 2003, R. Vásquez et al. 28287 ( US, USM) GoogleMaps .