Crotalaria balansae Micheli (1883:9)

Flores, Andréia Silva & Tozzi, Ana Maria Goulart De Azevedo, 2018, A synopsis of the genus Crotalaria (Leguminosae) in Brazil, Phytotaxa 346 (1), pp. 31-58 : 34-35

2. Crotalaria balansae Micheli (1883:9)

Type: — PARAGUAY. Caaguazu in campis, undated, B. Balansa 1850 (holotype: G digital image!).

Herbs or subshrubs to 50 cm high; branches pilose, erect to ascending; internodal stem wings (0.8–)1–5 × 0.5–2 cm, triangular, acuminate, upwardly directed. Leaves simple, blades oblong, oblong- elliptic or elliptic, 3–5.5 × 0.5–2 cm, pilose above and beneath; stipules absent. Inflorescence a raceme, 3–10 cm long, opposite to a leaf; peduncles 2–4.5 cm long. Flowers 1–5, pedicels 3–10 mm long; bracts 5–10 × 1–2 mm, elliptic- lanceolate, persistent; bracteoles 3–9 × 1–2 mm, elliptic- lanceolate, persistent; calyx 7–16 mm long, deeply divided into 2 lips, pilose; corolla yellow; the standard petal 0.8–1.3 × 0.5–0.9 cm; wing petals 0.6–1.2 cm long; keel petals 0.8–1.1 cm long, twisted; ovary 5mm long, sessile; style geniculate. Legumes 2.5–3.5 × 0.7–1.5 cm, oblong- clavate, glabrous, black at maturity, ca. 30- seeded; seeds 3 × 2 mm, seed coat brown.

Distribution and ecology: — Crotalaria balansae is known from Paraguay, Brazil and Argentina ( Gómez-Sosa 2000). In Brazil it occurs in the states of Tocantins, São Paulo, Rio de Janeiro, Mato Grosso do Sul, Paraná, Santa Catarina and Rio Grande do Sul. This species grows in sandy or clay soils in cerrado vegetation and disturbed grassland areas.

Note: —The internodal wings of C. balansae are variable in size from 0.8 to 5cm long. Because of that, this species is commonly confused with C. stipularia Desvaux (1814: 76) and C. velutina Bentham (1839:429) , all of which have internodal wings of similar length as well as similar habits and flower morphology. Crotalaria stipularia is distinguished by its falcate internodal wings, the apressed and sericeous vestiture of the stems and leaves, and flowers up to 1 cm long. Crotalaria velutina differs by its narrower or reduced internodal wings, and flowers 10–17 mm long.

Selected specimens examined: — BRAZIL. Mato Grosso do Sul: Ponta Porã, 14 February 1964, Gomes Jr. 1529 (UB, SP). Paraná: Arapoti, PR 092, 13 December 1998, Flores 282 (ICN). Rio de Janeiro: Petrópolis, December 1943, Góes & Constantino 882 (RB). Rio Grande do Sul: Arroio do Sal, 17 October 1998, Flores & Rodrigues 208 (ICN). Santa Catarina: Sombrio, 6 February 1946, Reitz 1422c (HBR). São Paulo: Itararé, 18 August 1995, Souza et al. 8747 (UEC). Tocantins: Palmas, Serra do Lageado, 13 April 1994, Ramos 655 (UB, HEPH).