Rhynchosia rojasii Hassl., Repert.

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 : 58-59

25. Rhynchosia rojasii Hassl., Repert. Spec. Nov. Regni Veg 7: 77. 1909. Type: — PARAGUAY, “Sierra de Amambay ad margines silvarum, in via sylvatica “ Picada ” dicta pr. Punta Porá, flor. et cum fruct. mat. mens.”, April 1907 -08 (fl.), Rojas 10424 (Lectotype, first-step designated by Grear [1978]; second-step designated here: G 00400154 [digital image!]; isolectotypes: BAB 000498 [fragment] [digital image!]; BM 000538498 [digital image!]; C 10012341 [digital image!]; F 1539661 [digital image!]; G 00400118, 00400119, 00400120 [digital image!]; K 000502975 [digital image!]; LIL 000653 [digital image!]; MICH 1104298 [digital image!]; MO 277413 [digital image!]; NO 0109890 [digital image!]; NY 00026954[!]; P 00709025 [digital image!]; RB 00540411 [digital image!]; S S-R-9731 [digital image!]; SI 002527 [digital image!]; UC 934985 [digital image!]; US 00004824 [digital image!];). Iconography: Rodriguésia 70: 17. 2019

Rhynchosia ituana Hoehne, Bol. Inst. Brasil. Sci. 2: 253. 1926. Type: BRAZIL, São Paulo, Itú , July 1917 (fl.), A. M. Diniz s.n. (Holotype:

SP 001039 [!]).

Vines herbaceous or suffrutescent, twining, stems simple or branched, pilose to pubescent, indumentum light yellow to yellow, with yellow vesicular glands and a few bulbous-based trichomes. Stipules 7.1–10 × 1–2.5 mm, free, persistent, lanceolate, externally pubescent with yellow vesicular glands, but lacking bulbous-based trichomes. Leaves trifoliolate; petiole 3.5–10.2 cm long; leaf rachis 2–3 cm long; stipels persistent; leaflets 4.1–11.7 × 2.8–8.9 cm, ovate, deltoid or rhombic, surface not bullate, attenuate or acute at apex, obtuse, truncate, or rounded at base, margin repand to entire, pilose, with yellow vesicular glands on abaxial surface. Inflorescences axillary, racemose or paniculate, 13–28 cm long, many-flowered, exceeding the length of the subtending leaf; bracts caducous; pedicels 2–4 mm long. Flowers 7–13 mm long excluding the pedicel; calyx 4–6 mm long, pubescent with yellow vesicular glands and sparse bulbous-based trichomes, lobes lanceolate, not exceeding the corolla in length; standard petal 9–12 × 8–9 mm, oblong or obovate, retuse to rounded at apex, pilose to pubescent, with yellow vesicular glands, but lacking bulbous-based trichomes, claw 1–1.5 mm long, auricle ca. 0.5 mm long; wing petals 9.5–10.5 × 1–2 mm, oblong, claw 1–2.5 mm long, auricle ca. 0.5 mm long; keel petals 10–12 × 2–4 mm, falcate, claw 2–3 mm long; stamens 10–13 mm long; ovary 2.9–3.5 mm long, pubescent, with yellow vesicular glands. Fruits 3–4 × 0.5–0.8 cm, greenish to brownish, without constrictions between the seeds, narrowly obovate, pilose to pubescent, with yellow vesicular glands, but lacking bulbous-based trichomes. Seeds 4–6 × 3–4 mm, ovate or reniform, unicolored, brown to dark brown.

Nomenclatural and taxonomic notes:— Rhynchosia rojasii was described by Hassler (1909) based on the collection Rojas 10424. There are several duplicates of that collection deposited in different herbaria, and the author did not cite a specific specimen as type. Grear (1978) cited a Rojas 10424 specimen at G as holotype, but there are four duplicates of the collection in G (G 00400154, G 00400118, G 00400119 and G 00400120) and he did not specify a particular one as type. Therefore, the citation of Grear (1978) constitutes the first-step lectotypification and our designation of the specimen with barcode number G 00400154 constitutes the required second-step (see Turland et al., 2018: Art. 9.17).

Rhynchosia rojasii morphologically resembles R. melanocarpa by its vegetative and flower characters; both species have persistent stipels, inflorescences exceeding the length of the subtending leaves and by the length of the pedicels. However, they are easily differentiated by their fruits, which in R. rojasii are greenish to brownish (vs. reddish-brown to black in R. melanocarpa ), without constriction between the seeds (vs. constricted between the seeds) and narrowly obovate (vs. oblong to ovate).

Reproductive phenology: —The species flowers from April to July; and fruits from May to July and September.

Distribution and habitat: — Rhynchosia rojasii occurs in Argentina, Brazil and Paraguay ( Fig. 15 ). However, Tropicos (www.tropicos.org) mentions that the species also occurs in Bolivia, but we have not confirmed this. It can be found along forest edges, in humid forest and on limestone hills.

Conservation status: —Least Concern ( LC). Based on an EOO of 810,908. km 2 (GeoCAT, accessed in May 2022), R. rojasii is assessed as LC according to the IUCN Red List criteria ( IUCN 2022). There are some records of this species in Argentina and Paraguay, and several in Brazil, especially in São Paulo state.

Selected Specimens Examined:— ARGENTINA. Misiones: Guaraní, Predio Guaraní, 26º54’59” S 54º12’18” W, Camino al ayo, 17 September 1998 (fr.), S. G. Tressens et al. 6076 ( MBM, NY) ; San Ignacio, Camiño a La Plantadora, July 1927 (fr.), A. Scala s.n. ( NY) . BRAZIL. Distrito Federal: Brasília, Côrrego Landim , 9 July 1966 (fl./ fr.), H. S. Irwin et al. 18101 ( NY, UB) . Minas Gerais: Pitangui , 20 June 1945 (fl.), L. O. Williams & V. Assis 7311 ( SP) .

Paraná: Arapuã, orla da mata pluvial das marges do Rio Ivai , 3 June 1963 (fl./fr.), G. Hatschbach 10103 ( MBM) ; Foz do Iguaçu, Parque Nacional do Iguaçu, estrada do Tamanduá , 17 May 1949 (fr.), A. P Duarte & E. Pereira 1790 ( NY) ; Jundiaí do Sul, Bairro Rio Vermelho , 3 May 2001 (fl.), J. Carneiro 1121 ( MBM) ; Laranjeiras do Sul, Salto Osório, Rio Iguaçu , 18 May 1970 (fl./fr.), G. Hatschbach 24162 ( MBM) . Rio Grande do Sul: Tenente Portela, Parque Estadual do Turvo , 8 July 1980 (fr.), J. R. Stehmann s.n. ( ICN) . São Paulo: Campinas, Fazenda Santa Genebra , s.d. (fl.), A. L. M. Franco 31767 ( UEC) ; ibid., Reserva Municipal de Santa Genebra 22º49’45’’S 47º06’33’’W, 25 May 1996 (fl./fr.), M. T. Grombrone-Guaratini, J. C. Galvão & R. Belinelo 36 ( UEC) ; Piracicaba, Mata da Pedreira , ESALQ/SP, 04 May 1984 (fl.), E. L. M. Catharino 60 ( SP) ; Porto Feliz, Rodovia Marechal Rondon , km 142,5, 13 May 2018 (fl.), G. M. Antar & V. B. Caetano 2138 ( CEN) . São Paulo, Butantan, cultivada no horto Oswaldo Cruz , 28 April 1920 (fl.), F. C. Hoehne 15949 ( NY) ; ibid., cultivada no Jardim Botânico de São Paulo, 10 May 1940 (fl.), O. Handro s.n. ( SP) ; São Roque , mata secundária, 26 April 1994 (fl.), R. B. Torres et al. 134 ( SP) . PARAGUAY. Alto Parana: Reserva Biológico Limoy de Itaipu Binacional , 18 April 1986 (fl.), D. R. Brunner & S. Cabellero 1872 ( RB) . San Pedro: Yaguarete Forest, trail to Rio Araguay , 31 July 1996 (fl.), E. M. Zardini & M. Vera 45368 (P); “Sierra de Amabay”, April 1907 -08 (fl.) T. Rojas 10424 ( US) .

Figures

FIGURE 15. Geographical distribution of Rhynchosia reticulata, R. rojasii, R. schomburgkii and R. senna in South America.