Rhynchosia lineata Benth., Fl. Bras.

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 : 37-39

16. Rhynchosia lineata Benth., Fl. Bras. 15(1B): 202. 1862. Type:— BRAZIL, “ Province de Rio-Grande ”, 1883, (fl.), C. Gaudichaud 1502 (Lectotype, designated here: P 02749054 [digital image!]). Iconography: Rodriguésia 70: 9. 2019. ( Fig. 10 A–B )

Subshrub erect, stems few branched or branched, pilose to pubescent, indumentum white to light yellow, with yellow vesicular glands, but lacking bulbous-based trichomes. Stipules 2–3 × 0.5–2 mm, free, persistent to falling late, lanceolate, externally pubescent with yellow vesicular glands, but lacking bulbous-based trichomes. Leaves trifoliolate; petiole 0.5–1.2 cm long; leaf rachis 0.4–0.7 cm long; stipels absent; leaflets 1.7–5.6 × 0.3–1.4 cm, narrowly lanceolate to linear, surface not bullate, attenuate to acuminate at apex, acute at base, margin entire, pubescent to tomentose, with yellow vesicular glands on both surfaces. Inflorescences terminal or axillary, racemose, 3.4–8.7 cm long, many-flowered, equaling or exceeding the length of the subtending leaf; bracts caducous; pedicels 1.5–2 mm long. Flowers 7–9 mm long excluding the pedicel; calyx 7.6–9.4 mm long, pilose to pubescent with yellow vesicular glands, but lacking bulbous-based trichomes, lobes lanceolate, all of them equaling or exceeding the corolla in length; standard petal 6–8 × 3–5 mm, elliptical or oblong, emarginate or rounded at apex, glabrous, lacking vesicular glands and bulbous-based trichomes, claw 1–2 mm long, auricle ca. 0.5 mm long; wing petals 5–7.5 × 1–1.5 mm, oblong, claw 1–2 mm long, auricle ca. 0.5 mm long; keel petals 6–9 × 1.5–2.5 mm, falcate, claw 1.5–2.5 mm long; stamens 6–10 mm long; ovary 2.9–4.1 mm long, densely pubescent, with yellow vesicular glands. Fruits 1.1–1.9 × 0.5–0.6 cm, brown, without constrictions between the seeds, oblong or elliptical, pilose to pubescent, with a few yellow vesicular glands and bulbous-based trichomes. Seeds 2–3 × 2–3 mm, suborbicular, unicolored, brown to black.

Nomenclatural and taxonomic notes: —In the protologue of Rhynchosia lineata , four collections were mentioned: “Habitat in prov. Rio Grande do Sul: Arsene Isabelle”, “Hb. Imp. Br. n. 1502”, “in silvis prope Aldea ejusdem prov.: Tweedie” and “in Banda Oriental: A. de St. Hilaire”. Grear (1978) lectotypified the species with the collection A. de St Hilaire 2509 housed in K (K 000502968). As Bentham (1862) did not mention the collection number “2509” in the protologue to his species, and there is no clear information on the Kew specimen selected by Grear that matches the protologue, we do not follow the lectotypification of Grear (1978). Instead, we select here the collection “Hb. Imp. Br. n. 1502” at P with barcode P 02749054 as a lectotype of R. lineata .

Rhynchosia lineata is characterized by having an erect subshrub habit, by its leaflets that are narrowly lanceolate to linear and by its glabrous corolla ( Fig. 10 A–B ). The arrangement of flowers on the inflorescence is variable, which it can be lax or congested at the apex, in the latter case, resembling R. corylifolia .

Reproductive phenology: — Rhynchosia lineata has been collected with flowers from January to March and October to December and with fruits from January to March and December.

Distribution and habitat: — Rhynchosia lineata is distributed in northeastern Argentina, Brazil and Uruguay ( Fig. 9 ). Miotto (1988) mentioned that the species also occurs in Paraguay, but we have not been able to confirm this. The species grows in pampean enviroments.

Conservation status: —Least Concern ( LC). Based on an EOO of 275,677 km 2 (GeoCAT, accessed in May 2022), R. lineata is assessed as LC. There are many records of this species from Brazil and Argentina.

Selected Specimens Examined:— ARGENTINA. Corrientes: Dep. Santo Tomé, Virasoro, al Oeste 12 km, 14 November 1944 (fl.), F. Ibarrola 1240 ( NY) . Entre Rios: Fedaracion, Salto Grande , 14 December 1974 (fl.), A. Burkart et al. 30875 ( US) ; Misiones: Dep. Candelaria, Mártires Brete , 17 February 1945 (fl.), A. Burkart 15448 ( MBM) . BRAZIL. Rio Grande do Sul: Alegrete, Cerro do Tigre , February 1990 (fl.), M. Sobral 6372 ( FLOR, UEC) ; ibid., parada de trem Perau , 29 October 1989 (fl.), L. A. Z. Machado 265 ( SMDB) ; ibid., próximo a parada de Trem Tigre, 05 January 1990 (fl./fr.), A. Alvarez & L. Machado 472 ( SMDB) ; Augusto Pestana, Pestana p. Ijuí , 19 February 1954 (fl.), Pivetta 1041 ( PACA) ; Bossoroca, Bossoroca / Coimbra , 12 January 1991 (fl.), L. A. Z. Machado et al. 835 ( SMDB) ; ibid., 12 January 1991 (fr.), L. A. Z. Machado et al. 839 ( SMDB) ; Caçapava do Sul, Caiera, BR 392, 24 December 1988 (fl.), L. A. Z. Machado 106 ( SMDB) ; ibid., Passo do Salso , 26 December 1988 (fl./fr.), L. A. Z. Machado 111 ( SMDB) ; Campanha , January 1972 (fl.), Pott 122 ( BLA) ; Carazinho, about 10 km SW of Carazinho, on road to Cruz Alta , 17 March 1991 (fl./fr.), T. M. Pedersen 15728 ( MBM, NY) ; Caxias do Sul, Vila Oliva p. Caxias , 29 January 1946 (fl.), E. Rambo s.n. ( PACA) ; ibid., Vila Seca , 12 January 2000 (fl.), L. Scur 360 ( MBM) ; Erechim, Gaurama Km 12, 11 December 1964 (fl.), K. J. F. Valls 4625 ( BLA) ; Esmeralda, 9 km após Esmeralda em direção a L. Vermelha, 5 January 1978 (fl./fr.), S. Miotto 823 ( BLA) ; Ijui p. Tupanciretã , 30 January 1942 (fl.), B. Rambo s.n. ( PACA) ; Ipiranga do Sul, BR 153, 27 December 1995 (fl.), R. Wasum et al. 11404 ( MBM, NY) ; Jari, Jari p. Tupanciretã , 27 January 1942 (fl.), B. Rambo 9430 ( PACA) ; Manoel Viana, Manoel Viana / Santiago , 16 January 1991 (fl.), Machado et al. 1139 ( SMDB) ; Nonoai, Nonoai p. fl. Uruguay , March 1945 (fl.), B. Rambo s.n. ( PACA) ; Passo Fundo, In campestribus dumetosis, 1941 (fl.), I. Edesio s.n. ( PACA) ; Santa Cruz do Sul, Sítio , 14 December 1950 (fl.), A. Sehnem 5082 ( PACA) ; Santa Maria , 15 October 1938 (fl.), E. Rambo s.n. ( PACA) ; ibid., Estação Experimental de Silvicultura , 2 January 1956 (fr.), O. R. Camargo 2069 ( BLA) ; ibid., 25 January 1956 (fl.), O. Camargo 101 ( PACA) ; ibid., 10 March 1956 (fl.), O. Camargo 46 ( PACA) ; ibid., Santa Flora , 28 March 1991 (fl.), Machado et al. 1320 ( SMDB) ; Santiago, a 2 km da cidade, saída para São Francisco de Assis , 07 March 1990 (fl.), I. Barreto & L. Machado 578 ( SMDB) ; ibid., Capão do Cipó, Assentamento Santa Rita , 05 January 1989 (fl.), L. A. Z. Machado 135 ( SMDB) ; São Borja, BR 287, 14 January 1991 (fl.), Machado et al. 1013 ( SMDB) ; São Francisco de Assis, rumo à Santiago , 16 January 1991 (fl.), Machado et al. 1240 ( SMDB) ; Sobradinho, Sobradinho / Manoel Viana , 15 January 1991 (fl./fr.), Machado et al. 1055 ( SMDB) ; Soledade, Boqueirão do Butiá, RS 332, Km 106, 09 January 1999 (fl.), S. T. S. Miotto s.n. ( SMDB) ; Tupanciretã , January 1935 (fl.), A. A. Araujo 1 ( BLA) ; ibid., 27 January 1942 (fl.), B. Rambo 3860 ( SP) ; ibid., Estação Experimental , 7 February 1969 (fl./fr.), Pott 78 ( BLA) ; ibid., Passo da Lage , 11 January 1991 (fl./fr.), Machado et al. 776 ( SMDB) ; Vacaria, Est. Exp. De Vacaria , 24 January 1990 (fl.), Machado & Polking 545 ( SMDB) . Santa Catarina: Campos Novos , 31 January 1963 (fl.), R. Reitz 6417 ( FLOR) . URUGUAY. Cerro Largo: Cerro de las Cuentas , unica ruata en esquedal, 29 December 1938 (fl.), Roseugartd B-2783 ( NY) . Dep. Durazno, Estancia Las Palmas , March 1922 (fl./fr), C. Osten 16858 ( BHCB) ; Dep. Rivera, Cuñapirú , 26 January 1977 (fl./fr.), T. M. Pedersen 11644 ( MBM, NY) ; ibid., 19 January 1995 (fl./fr.), T. M. Pedersen 16207 ( MBM) .

Figures

FIGURE 9. Geographical distribution of Rhynchosia hauthalii, R. lateritia, R. leucophylla and R. lineata in South America.

FIGURE 10. Rhynchosia species. A, B. R. lineata. C–F. R. mantaroensis var. cuprinervia. G–J. R. melanocarpa. K–N. R. minima. (A, B by A. Mailhos); (C–F by R. Ripley) and (G–N by T. C. Monteiro).