Justicia werffii J. R. I. Wood & R. Villanueva, 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

34. Justicia werffii J. R. I. Wood & R. Villanueva sp. nov.

Type.

Peru • San Martin, Prov. Rioja, Carretera Rioja [6°03'S, 77°10'W] – Pedro Ruiz [5°57'S, 77°58'W], 1450 m, 2 March 1998, H. Van der Werff 15565 (holotype MO-5763942 , isotypes US-3387908 , USM) .

Diagnosis.

A small-flowered species that resembles J. morona-santiagoensis Wassh. in the spathulate bracts but differs in the liana habit (not erect or ascending subshrub), short peduncles, 0.5–2 cm long (not 4–6 cm) and the ciliate bracts and bracteoles (not glabrous).

Description.

Liana of unknown height; stems sulcate, glabrous. Leaves petiolate, lamina 2.5–6 × 1–2.3 cm, apex acuminate, base cuneate, slightly oblique, margin entire to crenulate, subglabrous or with few hairs in the veins, numerous small cystoliths present, veins 5–6 pairs; petioles 3–7 mm, subglabrous or hirtellous. Inflorescence of solitary or paired axillary racemes 1–4 cm long, becoming aggregated apically to form a terminal thyrse, the leaves progressively reduced in size; peduncles 0.5–2 cm, glabrous; rhachis 0.5–2 cm long, scurfy; flowers on pedicels 0–2 mm long; bracts and bracteoles similar, spathulate, 4 × 1.5 mm, ciliolate; calyx 5 - lobed to c. 1 mm above base, lobes 4 × 0.5 mm, lanceolate, acuminate, puberulent; corolla c. 12 mm long, white, minutely tomentellous, the tube c. 3.5 mm, the base somewhat bulbous, upper lip c. 8 mm long, minutely notched, erect, lower lip c. 6 mm, 3 - lobed, lobes c. 2–2.5 × 1.5–2 mm, narrowly ovate, obtuse; anthers shortly exserted, thecae ellipsoid, c. 1.5 × 1 mm, slightly superposed, glabrous, basally acute; pollen prolate, 29–35 × 16–21 μm, 3 - aperturate, colporate, 1 row of ± 7–8 distinct insulae on either side of aperture (Fig. 51 B ); style 12 mm, glabrous except for a few hairs at base; ovary glabrous. Capsule and seeds not seen.

Illustration.

Fig. 33 .

Etymology.

This species is named for Henk van der Werff, who collected the type as well as many other important specimens from northern Peru.

Phenology.

Found in flower in March.

Habitat.

Montane forest on clay soil in San Martin, 1450 m.

Distribution.

Endemic to Peru and only known from the type, which was collected in San Martin. Fig. 64 .

Material examined.

Peru • San Martin: type collection .

Figures

Figure 33. Justicia werffii A habit B detail of abaxial surface of leaf C bract D bracteole E calyx F corolla G anther H ovary and style. Drawn from Van der Werff 15565 by Margaret Tebbs.

Figure 51. Pollen images A Justicia warmingii (Villanueva 920) B J. werffii (Van der Werff 15565) C J. schunkei (Schunke 7599) D J. spathuliformis (Villanueva 1028) E J. saccata (Villanueva 997) F J. lactiflora (Woytkowski 34339). Scale bars: 10 μm.

Figure 64. Distribution of Justicia chlamydocardioides (red polygons), J. schunkei (blue circles), J. werffii (yellow square) and J. spathuliformis (green triangles) in Peru.