Rhynchosia mantaroensis J.F. Macbr., Publ. Field Mus. Nat. Hist., Bot. Ser.

Bezerra, Luísa Maria De Paula Alves, Cândido, Elisa Silva, Vargas, Wanderleia De, Torke, Benjamin Marland, Lewis, Gwilym Peter & Perez, Ana Paula Fortuna, 2024, Taxonomic revision of Rhynchosia Lour. (Leguminosae, Papilionoideae, Phaseoleae) in South America, Phytotaxa 643 (1), pp. 1-67 : 39-40

17. Rhynchosia mantaroensis J.F. Macbr., Publ. Field Mus. Nat. Hist., Bot. Ser. 8(2): 105. 1930.

Vine suffrutescent, twining, stems simple or branched, sericeous, puberulous, or pilose to pubescent, indumentum white to light yellow, with sparse yellow vesicular glands, but lacking bulbous-based trichomes. Stipules 2.5–6.5 × 1.6–3 mm, free, persistent, lanceolate to triangular, externally pubescent to tomentose with yellow vesicular glands, but lacking bulbous-based trichomes. Leaves trifoliolate; petiole 1.3–3.5 cm long; leaf rachis 0.5–1.1 cm long; stipels persistent; leaflets 1.8–8.2 × 1.3–4.8 cm, ovate, elliptical, or deltoid, surface not bullate, acute to acuminate at apex, obtuse to rounded at base, margin entire, pubescent, villous or densely tomentose, with yellow vesicular glands on the abaxial surface. Inflorescences axillary, racemose or paniculate, 6–29.5 cm long, many-flowered, equaling or exceeding the length of the subtending leaf; bracts caducous; pedicels 0.5–4 mm long. Flowers 9–13 mm long excluding the pedicel; calyx 5–9 mm long, pubescent with yellow and black vesicular glands and sparse bulbous-based trichomes, lobes triangular, not exceeding the corolla in length; standard petal 10–12 × 7–9 mm, obovate, rounded at apex, pilose to pubescent, with yellow vesicular glands and rare bulbous-based trichomes, claw ca. 2 mm long, auricle ca. 0.5 mm long; wing petals 9–10 × 1.3–1.6 mm, oblong, claw ca. 2 mm long, auricle ca. 0.5 mm long; keel petals 9–11 × 2.6–3 mm, falcate, claw 3–4 mm long; stamens 10–12 mm long; ovary 3.5–4 mm long, pubescent, lacking vesicular glands. Fruits 1.8–3 × 0.7–1.3 cm, greenish to brownish, without constrictions between the seeds, oblong, pubescent to hirsute, with yellow vesicular glands and bulbous-based trichomes. Seeds 3–4.5 × 2.5–3 mm, suborbicular, unicolored, brown to black.

Key to varieties of Rhynchosia mantaroensis

Leaflets pubescent to villous beneath; inflorescences 6–10.5 cm long; pedicels 2–4 mm long....................................................................... ....................................................................................................................................... Rhynchosia mantaroensis var. mantaroensis

Leaflets densely tomentose beneath; inflorescences 12.2–29.5 cm long; pedicels 0.5–1.5 mm long ............................................................. ......................................................................................................................................... Rhynchosia mantaroensis var. cuprinervia