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.