Justicia tumbesiana 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

10. Justicia tumbesiana R. Villanueva & J. R. I. Wood sp. nov.

Type.

Peru • Tumbes, Prov. Zarumilla, Dist. Matapalo, entre P. C. “ El Caucho ” y P. C. “ Campoverde ”. Bosque Nacional de Tumbes. Reserva de Biósfera del Noroeste , 3°50'29"S, 080°15'33"W, 720 m, 24 July 1992, Camilo Díaz S., H. Horna & A. Peña Cruz 5081 (holotype MO-04651117 , isotypes MEXU, MOL, US, USM – 3 sheets) .

Diagnosis.

Bears an obvious superficial resemblance to Justicia appendiculata in the large, dark, sometimes reddish inflorescence bracts and the tubular red, pubescent corolla but leaves broadly oblong-elliptic (not narrowly oblong-elliptic), the inflorescence shorter, to 10 cm long (not up to 15 cm), the lateral branches subsessile (not clearly pedunculate), the floral bracts prominent, oblanceolate, up to 10 mm long (not inconspicuous, ovate c. 2–3 mm long).

Description.

Shrub 3.5 m high; stem woody, bark pale brown, peeling, glabrous. Leaves subequal in each pair, petiolate, lamina 8–18 × 3.5–8 cm, broadly oblong-elliptic, apex very shortly acuminate, base cuneate and shortly decurrent, margin crenulate, both surfaces glabrous with abundant small cystoliths, abaxially paler, slightly glaucous, the venation highlighted-white, lateral veins 8 pairs; petioles 0.7–5 cm. Inflorescence of short axillary spikes up to 10 cm long and 3 cm wide (excluding expanded corolla), peduncles c. 1.5–2.5 cm, scurfy; rhachis bifariously scurfy; inflorescence bracts 4–5 × 1–2 cm, narrowly obovate, dark coloured, glabrous; flowers arising in short opposite spikes of indeterminate form borne on a puberulent lateral branch up to 1 cm long, superficially appearing verticillate; floral bracts 1 × 2–4 mm, oblong-oblanceolate, puberulent, often purplish; bracteoles 7 × 1 mm, oblong, puberulent; pedicels c. 1 mm, puberulent; calyx 5 - lobed, lobes 5 × 1 mm, lanceolate, acuminate, puberulent; corolla 3 cm long, orange, pubescent with gland-tipped hairs, subcylindrical, tube gradually widened from 1 mm at base to 5 mm after c. 18 mm, upper lip 12 mm long, entire, lower lip c. 12–13 mm long, 3 - lobed, lobes oblong, 4 × 2 mm, obtuse; filaments c. 22 mm long, pilose below, anther thecae oblong, c. 2.5 × 0.5 mm, glabrous, lower with a basal appendage, parallel, slightly superposed; pollen prolate, 40–55 × 25 μm, 2 - aperturate, colporate, 1 row of 6–7 insulae on either side of aperture with a second row sometimes grading into peninsulae (Fig. 49 D ); style thinly pilose below, glabrous above; ovary narrowly ovoid, c. 2.5 mm high, black, glabrous. Capsule and seeds not seen.

Illustration.

Fig. 13 .

Etymology.

This species is named Justicia tumbesiana after Tumbes region, where it is the only recorded species in the genus. The Bosque Nacional de Tumbes in the Reserva de Biósfera del Noroeste is an isolated area of woodland near the Pacific Ocean in Peru’s otherwise arid coastal region.

Phenology.

Found in flower in July.

Habitat.

Woodland at 720 m.

Distribution.

Endemic to Tumbes in Peru and only known from the type collection. Fig. 56 .

Material examined.

Peru • Tumbes: Only known from the type collection .

Figures

Figure 13. Justicia tumbesiana A habit B detail of abaxial surface of leaf C bract D bracteole E calyx F corolla opened out to show stamens G anther H ovary and style base. Drawn from Diaz et al. 5081 by Margaret Tebbs.

Figure 49. Pollen images A Justicia chamaecaulis (Encarnación 927) B J. appendiculata (Villanueva 916) C J. pelianthia (McDaniel 21499) D J. tumbesiana (Diaz 5081) E J. aphelandroides (Wurdack 2245) F J. sanchezioides (Schunke 12458). Scale bars: 10 μm.

Figure 56. Distribution of Justicia appendiculata (red circles), J. aphelandroides (yellow square) and J. tumbesiana (green triangle) in Peru.