Justicia discolor subsp. filisepala 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 b. Justicia discolor subsp. filisepala J. R. I. Wood & R. Villanueva subsp. nov.

Type.

Peru • Loreto, Prov. Maynas, Dist. Mazán, 6 km from Fundo Buenas Aires, Río Tamishiyacu , 20 June 1977, F. Encarnación 1107 (holotype K-000544764 , isotype US-2956915 ) .

Diagnosis.

Closely related to Justicia discolor subsp. discolor but a slender herb, the leaves concolorous, elliptic, obtuse, thin in texture, 2–5 (– 6) × 1–4 cm, c. twice as long as broad, glabrous or thinly pilose, (not discolorous, purple abaxially, lanceolate or ovate, acuminate, relatively firm in texture, 1.5–9.5 × 0.6–4 cm, mostly more than 3 times as long as broad); inflorescence lax, the flower pairs up to 22 mm apart (not imbricate, not more than 10 mm apart); calyx lobes filiform (not linear).

Description.

Slender near isophyllous creeping herb, rooting at nodes; stems to 25 cm, bifariously crisped-pubescent, glabrescent when old, cystoliths prominent and abundant. Leaves petiolate, lamina 2–5 (– 6) × 1–4 cm, broadly ovate, oblong-ovate, to elliptic, apex obtuse to rounded, base broadly cuneate, margin undulate to weakly crenate, glabrous or thinly pilose adaxially with multicellular hairs, cystoliths abundant on both surfaces, slightly paler beneath; petioles 3–4 mm. Inflorescence of short, pedunculate terminal spikes, 1–3 cm long, elongating to 8 (– 14) cm in fruit, usually solitary but occasionally with a small secondary spike from the uppermost leaf axils; flowers relatively distant, up to 22 mm apart at base of spike; peduncles 1–1.8 cm at anthesis but up to 6 cm in fruit, shortly pilose with gland-tipped whitish hairs; rhachis shortly pilose with gland-tipped whitish hairs, the flowers in opposite pairs, ± imbricate with internodes up to 3 mm long at anthesis but up to 22 mm in fruit, bracts 4–5 × 0.5 mm, linear, mucronulate, shortly pilose with gland tipped hairs, cystoliths prominent; bracteoles similar but only c. 2.5 mm long; calyx subequally 4 - lobed to base, lobes linear-filiform, 7.5–8 × 0.25–0.5 mm, accrescent in fruit to 10 mm long, shortly pilose with gland-tipped hairs; corolla pale lilac, glabrous externally, 11–12 mm long, upper lip c. 4 mm long, subentire, lower lip 3 - lobed, c. 6 mm long, lobes ovate, rounded; stamens glabrous, anther thecae 0.5 × 0.25 mm, oblong, superposed, glabrous, the lower with an almost imperceptible basal appendage; pollen prolate, 33–36 × 21 μm, 2 - aperturate, colporate, a distinct band of sexine on either side of aperture (Fig. 48 F ); style glabrous, c. 10 mm. Capsule 7–8 × 2 mm, clavate, apiculate, thinly pubescent, valves with prominent venation, strongly recurved after seeds are ejected, 4 - seeded; seeds 1.25 × 1.5 mm, tuberculate.

Illustration.

Fig. 11 A – J .

Etymology.

The name “ filisepala ” refers to the calyx lobes which are characteristically thread-like in this subspecies.

Phenology.

Found in flower in February, March and June.

Habitat.

Humid lowland rainforest, perhaps liable to flooding, 95– 190 m.

Distribution.

Endemic to Amazonian Peru in Loreto. Fig. 54 .

Material examined.

Peru • Loreto: Prov. Maynas, Gamitanacocha, Río Mazán , 100–125 m, 8 Feb. 1935, J. M. Schunke 192 (F, US, USM) ; • ibid., 6 km from Fundo Buenas Aires, Río Tamishiyacu, 20 June 1977, F. Encarnación 1107 (K, US). Prov. Mariscal Ramón Castilla, Río Yavari , 20 km río abajo de Angamos, Quebrada Curacinha, 5°03'05"S, 72°43'52"W, 95–190 m, 28 March 2003, H. Beltrán et al. 5429 (F, USM). 4

The following are more robust with concolorous leaves and might be seen as intermediate with subsp. discolor .

Additional material examined.

Peru • Ayacucho: Prov. La Mar, Río Catute, between Santa Rosa and Sanabamba , 700 m, 16 Sept. 1976, D. C. Wasshausen & F. Encarnación 1155 ( US) . Loreto, Región Amazonas, Caballococha , 3°55'S, 70°30'W, 106 m, 15 Aug. 1989, R. Vásquez & N. Jaramillo 12755 ( MO, US) .

Figures

Figure 11. Justicia discolor subsp. filisepala A habit B bract C bracteole D detail of indumentum E calyx F corolla G anther H capsule valve J seed. Justicia chamaecaulis K habit L bract M bracteole N calyx P corolla Q anther R capsule valve S seed. A – J drawn from Encarnación 1107 K – S from Encarnación 927 by Margaret Tebbs.

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.

Figure 54. Distribution of Justicia cuspidulata (yellow polygon), J. discolor subsp. discolor (orange circles), J. discolor subsp. filisepala (red squares) and J. rojasiae (green triangles) in Peru.