Justicia bambusiformis 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

40. Justicia bambusiformis J. R. I. Wood & R, Villanueva sp. nov.

Type.

Peru • Cusco, Prov. La Convención, Dist. Echarate, Llactahuaman, N del Río Apurímac, NE of Pueblo Libre , 12°51'55.5"S, 73°30'40"W 1650 m, 14 July 1998, S. Baldeón et al. 3215 (holotype US-3379708 , isotype USM) .

Diagnosis.

Distinctive species because of its tall, stout, subcylindrical stems, the flowers in short elongate cymose structures, mostly 2–4 cm in length, arranged in verticels in the axis of the leaves, the bracts reduced to scales.

Description.

Subshrub 1.5–4 m high; stems erect or ascending, bamboo-like in form, slender, pubescent with crisped, multicellular hairs. Leaves petiolate, lamina 10–17 × 2–4.5 cm, narrowly oblong-elliptic, apex acuminate, base attenuate, dark green, adaxially glabrous to very thinly pubescent with scattered hairs, abaxially glabrous apart from puberulent midveins; petioles 5–8 mm, puberulent. Inflorescence a long leafy raceme, at least 25 cm in length, possibly much more; flowers in slender elongate cymose structures, mostly 2–4 cm in length, several arising in the axils at each node; rhachis shortly but densely pubescent; bracts scale-like, c. 0.5 mm long; bracteoles linear, 2.5 × 0.5 mm; calyx subequally 5 - lobed to base, lobes 3 × 0.5 mm, ciliolate, puberulent; corolla 15–23 mm long, creamy-white / yellow, puberulent on exterior, cylindrical, 2 - lipped, upper lip 8 mm long, notched, lower lip shallowly 3 - lobed, the lobes c. 1 mm long, oblong, rounded; filaments glabrous, anther thecae weakly superposed, 1.25 mm long, upper apiculate at base, lower with a basal appendage; pollen prolate-perprolate, 38–40 × 19–20 μm, 3 - aperturate, colporate, 1 row of c. 5–8 insulae, (some coalescing) on either side of aperture (Fig. 52 A ); ovary oblong, acute to rostrate, 2.5–3 mm, glabrous, style puberulent, 20 mm long. Capsule 15 × 3 mm, clavate, glabrous, 4 - seeded; seeds 2 × 2 mm, glabrous, lenticular.

Illustration.

Fig. 40 .

Etymology.

The epithet “ bambusiformis ” refers to the distinctive habit of the species with its stout, subcylindrical stems and pseudoverticels of flowers in the leaf axils, recalling the habit of cloud forest bamboos of the genus Chusquea Kunth.

Phenology.

Found in flower in June and July.

Habitat.

Ceja de monte. Edge of bamboo thickets in cloud forest, 1650–1700 m.

Distribution.

Endemic to Cusco, La Convención. Fig. 69 .

Material examined.

Peru • Cusco: La Convención, 12°38'S, 73°36'W, 1700 m, 25 June 1968, T. R. Dudley 10440 ( NA, US) ; • ibid., Dist. Echarate, the type ; • ibid., Echarate, Katarompanaki, 12°11'12"S, 72°28'13"W, 1800 m, N. Salinas et al. 6840 ( USM) .

Figures

Figure 40. Justicia bambusiformis A habit B detail of abaxial surface of leaf C portion of inflorescence showing bracteole D calyx E corolla F anther G exterior of capsule valve H interior of capsule valve showing seed J seed. A, F drawn from Dudley 10440 G, J from Baldeon 3215 by Margaret Tebbs.

Figure 52. Pollen images A Justicia bambusiformis (Dudley 10440) B J. valenzuelae (Valenzuela 8722) C J. huallagensis (Knapp 7879) D J. oxapampensis (Villanueva 963) E J. falcifolia (Ortiz 660) F J. hyalina (Scolnik 909). Scale bars: 10 μm.

Figure 69. Distribution of Justicia bambusiformis (pink polygons), J. valenzuelae (red triangles), J. falcifolia (yellow squares) and J. hyalina (green circles) in Peru.