Justicia discolor 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

7. Justicia discolor J. R. I. Wood & R. Villanueva sp. nov.

Type.

Peru • Junín, Prov. Satipo, Dist. Río Negro , 800 m, 12 Aug. 1960, F. Woytkowski 5790 (holotype US-2960983 , isotypes MO-2923588 , US-2426094 ) .

Diagnosis.

Slender perennial herb with 4 - lobed calyx and terminal inflorescence resembling Justicia boliviana Rusby and allies but distinguished by the discolorous, nearly glabrous leaves, the glandular-pilose inflorescence, linear calyx lobes 7.5–9 × 0.25–0.5 mm, small glabrous corolla 10–12 mm long and thinly pubescent capsule.

Description.

Perennial herb; stems creeping, rooting at the nodes, eventually ascending to c. 50 cm, striate, glabrous to thinly hirtellous. Leaves equal to slightly unequal in each pair, shortly petiolate; lamina 1.5–9.5 × 0.6–4 cm, very variable in shape even on the same plant, commonly lanceolate to ovate, usually acuminate to an obtuse apex, base broadly to narrowly cuneate, sometimes slightly decurrent onto the petiole, margin undulate to conspicuously crenate, veins prominent, c. 5–6 pairs, discolorous, adaxially green with abundant cystoliths, abaxially usually conspicuously dark violet, both surfaces glabrous; petioles 3–7 mm, subglabrous to hirtellous. Inflorescence a terminal pedunculate spike, often solitary but sometimes with 1–2 secondary spikes from the uppermost leaf axils, spikes 1.5–6 (– 14) cm long; peduncles 1–3.5 (– 6) cm, thinly to densely glandular-pilose, rhachis glandular pilose, flowers in opposite pairs, c. 8 mm apart below, imbricate above; bracts 4–5 × 0.5 mm, linear-lanceolate, glandular-pilose; bracteoles similar but 2–3 × 0.25 mm; calyx 4 - lobed to base, lobes 7.5–9 × 0.25–0.5 mm linear to filiform, acuminate, accrescent in fruit, glandular-pilose; corolla lilac, purple or violet with white “ herring bone ” patterning, glabrous, 10–12 mm long, 2 - lipped, tube c. 6 × 1.5 mm, white or purplish, upper lip 2–4 mm long, entire, lower lip c. 6 mm long, shallowly 3 - lobed, lobes c. 1 mm long, ovate, rounded; filaments glabrous, anther thecae shortly oblong, 0.5 × 0.25 mm, superposed, glabrous, lacking basal appendages; pollen prolate, 35 × 21–22 μm, 2 - aperturate, colporate, 1 distinct band of sexine on either side of aperture (Fig. 48 E ); style 9–10 mm long, glabrous. Capsule 6–8 × 1.5–2 mm, narrowly clavate, apiculate, thinly glandular-pubescent, 4 - seeded; seeds 1 × 1.25 mm, cordate-ovoid, flattened, rugose, glabrous, reddish-brown.

Divisable into two geographical subspecies:

Figures

Figure 48. Pollen images A Justicia alpina subsp. machupicchuensis (Stafford 1222) B J. rojasiae (Vásquez et al. 28272) C J. pozuzoensis (Villanueva 925) D J. oppositiflora (Smith & Pretel 4189) E J. discolor subsp. discolor (Woytkowski 5824) F J. discolor subsp. filisepala (Beltrán 5429). Scale bars: 10 μm.