Crotalaria laeta Martius ex Bentham (1859:30)

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 : 41-42

16. Crotalaria laeta Martius ex Bentham (1859:30) . ( Fig. 3c , 6f ).

Lectotype (designated by Flores et al. 2016):— BRAZIL. “Prov. Piauhy. Brasilia tropica”, 1839, G. Gardner 2103 (K 000187675 digital image!)

Shrub or subshrub 0.4–0.6 m high; branches finely pubescent; internodal stem wings absent. Leaves 3-foliolate, digitate, petioles 1.5–3.3 cm long; leaflets ovate or elliptic, 3–4.2 × 1.3–1.5 cm, above and beneath puberulous; stipules 3–4 mm long, linear. Inflorescence a raceme, 8–30 cm long, opposite to a leaf; peduncles 2.7–4 cm long. Flowers 10–40, pedicels 2–4 mm long; bracts 2–3 mm long, linear- lanceolate, persistent; bracteoles linear, inconspicous, caducous; calyx 7–9 mm long, lobes twice as long as the tube, puberulous; corolla yellow or lilac; the standard petal 0.7–1.2 × 0.5–0.9 cm; wing petals 0.7–0.8 cm long; keel petals 0.9–1.1 cm long, glabrate or ciliate on the upper margin, untwisted; ovary 2–3 mm long, stipitate; style curved. Legumes 1.2–1.8 × 0.4–0.7 cm, oblong- ellipsoid, puberulous, brown at maturity, ca. 10-seeded; seeds 3 × 3 mm, seed coat orange.

Distribution and Ecology: — Crotalaria laeta occurs in areas of caatinga and cerrado vegetation in Northeastern, Southeastern and Central Brazil.

Note: — Windler & Skinner (1982) considered Crotalaria laeta Benth. as a variety of C. vitellina Ker-Gawler (1820: 447) based on the size of the inflorescences. However, a detailed analysis of the inflorescence size and flower morphology in all specimens available for this study showed that the size of inflorescences was not a reliable character to distinguish these varieties. In addition, we observed that the petal wing in C. laeta is smaller than the keel, the fruits are smaller (2–3.2 cm long in C. vitellina ), and the seeds are yellow (brown in C. vitellina ). Based on these characteristics we suggest that C. laeta should be recognized as a separate species.

Selected material examined: — BRAZIL. Bahia: Abaíra, 13º16’N 41º49”W, 24 February 1992, Stannard et al. H51567 (SPF). Ceará: Crateús, 18 June 1979, Coradin et al. 2028 (CEN). Mato Grosso: Poconé, 11 February 1978, Allem & Vieira 1673 (CEN). Mato Grosso do Sul: Camapuã, 08 February 1974, Hatschbach 33939 (UEC). Minas Gerais: Diamantina, Biribiri , 18 November 1984, Harley et al. s.n. (SP 350132). São Paulo: Assis, 18–25 February 1988, Leitão Filho et al. 20117 (UEC). Tocantins: Tocantinópolis, 06º49’S 47º49”W, 27 February 1980, Plowman et al. 9261 (INPA).

Figures

FIGURE 3. Habit of (a) Crotalaria holosericea Nees & Mart. (Flores et al. 757, UEC), (b) Crotalaria irwinii Windler & S.G. Skinner (Irwin et al. 21657, UB), (c) Crotalaria laeta Mart. ex Benth. (Flores et al. 793, UEC), (d) Crotalaria longirostrata Hooker & Arn. (Carvalho 34, VIC). Scale bar: 5 cm.

FIGURE 6. Habit of (a) Crotalaria breviflora DC., (b) Crotalaria flavicoma Benth., (c) Crotalaria grandiflora Benth., (d) Crotalaria harleyi Windler & S.G. Skinner, (e) Crotalaria holosericea Nees & Mart. (f) Crotalaria laeta Mart. ex Benth. Photos by A.S. Flores.