Chamaecrista jacobinea (Bentham) Irwin & Barneby (1982: 661)

Souza, Alessandro Oliveira De, Cavalcante, Raphael Guarda & Silva, Marcos José Da, 2022, Taxonomic revision of Chamaecrista sect. Absus subsect. Absus (Leguminosae, Caesalpinioideae) with adjustments in the new classification, Phytotaxa 565 (1), pp. 1-82 : 52-55

12. Chamaecrista jacobinea (Bentham) Irwin & Barneby (1982: 661) ≡ Cassia jacobinea Bentham (1870: 132) ≡ Cassia desertorum var. stylosanthifolia Bentham (1870: 134) . Type:— BRAZIL. Bahia: Jacobina, Habitat ad Morltlba in Serra Jacobina; s. dat., (fl., fr.), J.S. Blanchet 3676 (lectotype BM000793267! Designed by Irwin & Barneby (1978: 257), isolectotypes BR5118342!, C 10011986!, F0057583F!, F0057582F!, G00371014!, G00370970!, G00370993!, GH00053257!, LE00002337!, MO-714988!, P00836051!, U0003206!, W0028763!). (Figs. 23 and 24)

subshrubs perennial, 0.3–1.6 m tall, erect, cespitose or not. Root nodules absent. Branches brown when mature and green-yellow when young, both setulose-viscous and villosule including stipules, petiole and rachis; non-exfoliating bark. Stipules 0.5–1 × 0.4–0.5 mm, lanceolate, deciduous on adult leaves.Leaves alternate-spiral, regularly distributed along the stem, plagiotropic; petiole 0.9–2(2.5) cm long; rachis 0.5–1.2(1.5) cm long; leaflets 2 pairs, 0.9–2.5(3.3) × 0.6–1.5 cm, distal pair slightly larger than proximal pair, elliptical, oblong-elliptic or oboval, apex obtuse or rounded and mucronate, asymmetrical base in the distal pair and rounded in the proximal pair, papyraceous, discolored, dark green adaxial surface, glossy and glabrous or puberulent, light green and opaque abaxial surface, setulose-viscous and puberulent; margin entire, flat or revolute near base or apex, ciliate; secondary veins 4–6 pairs, conspicuous and slightly prominent on abaxial surface. Leafy appendix inter-petiolule absent. Racemes 4–16 cm long, peduncle 0.5–1 cm, 7–18 flowers, lax, terminal and axillary, erect with straight or flexuous axis, setulose-viscous and villous, including pedicel, external surface of bracts, bracteoles and sepals. Bracts 2.5–4.5 × 0.4 mm, linear or lanceolate, persistent. Bracts 2–4.5 × 0.4 mm, similar to bracts. Buds 5–8 × 3–4 mm, ovoid, apex acuminate. Flowers 2–2.5 × 0.8–1.5 cm; pedicel 0.7–1.1 cm long, straight and ascending even when fruited; sepals 10–11 × 3–4.0 mm, elliptical, apex acuminate, green with externally reddish macules; 4 flat oboval petals and 1 falcate-curled inner petal, 1–1.3 × 0.5–1 cm, yellow; stamens 10, 4–5 mm long, anthers not barbulate; ovary 2–3 × 1.5 mm, setulose and villous; style 8–9 mm long, curved in upper third, glabrous. Legumes 3–3.5 × 0.6–0.8 cm, oblong, setulose-viscous and sparsely puberulent, brown or green with reddish dotts. Seeds 5–6, 5–5.5 × 5–5.5 mm, oblong or obovoid, blackened.

Etymology:—in reference to Serra da Jacobina (Bahia), where the species was first collected.

Geographical distribution and habitat:— Chamaecrista jacobinea is an endemic species from the northern region of Chapada Diamantina in Bahia (Fig. 38D), where it grows in dense or thin shrubby or arboreal caatingas and in rocky fields, on sandy soils between 600 and 1100 meters in altitude.

Flowering and fruiting:—recorded with flowers from December to September, its flowering being more intense in May.

Conservation status: —Species with an estimated Occurrence Extension of 9,347 km 2, and therefore interpreted as Vulnerable (VU), criteria B (bi, ii, iii). However, its conservation is less worrying given that its area of occurrence covers environments with highly uneven reliefs, including the top of hills, belonging to the legal reserves of the Chapada Diamantina region.

Taxonomic history:— Cassia jacobinea was described by Bentham (1870) in Flora Brasiliensis based on the “Blanchet 3676” collection from Serra da Jacobina in Bahia. Bentham (l.c.), without realizing it, described C. deserterum var. stylosanthifolia based on a duplicate of the same type collection of C. jacobinea . Such a mistake was noticed by Irwin & Barneby (1978), who proposed the synonymization of C. deserterum var. stylosanthifolia under C. jacobinea claiming that both were described based on the same collection. That same year ( Irwin & Barneby 1978) reported that they did not find the holotype of C. jacobinea in Herbariums M and K, where it could be deposited, but found duplicates in the herbaria BM, C, F, G, GH, LE and P. From this situation, the authors considered the M specimen as lost, designating the BM duplicate as the C. jacobinea lectotype, and the other duplicates as isolectotypes.

Characterization and morphological relationships: — Ch. jacobinae , Ch. anamariae and Ch. chapadae are endemic species of Chapada Diamantina. The first and third are more similar to each other in terms of growth and leaflet shape and color. However, Ch. jacobinea can be readily recognized by its subshrub and cespitose habit, discolored and with indumentumin leaflets on both sides; racemes with buds with acuminate apex and short pedicels (0.7–1.1 cm long). The similarity of this species to Ch. chapadae , was discussed in the comments of the latter.

Specimens examined:— BRAZIL. Bahia: Campo Formoso, estrada Alagoinhas-Minas do Mimoso , 10º22’S, 41º19’W, 1050m, 26 June 1983, (fl.), L . Coradin et al. 6070 ( CEN, NY); Jacobina, Serra da jacobina, Morro do Cruzeiro , 23 December 1984, (fl.), G. P . Lewis et al. 36545 ( NY, SPF); ib., Serra de Jacobina (serra das Figuras), 11°09’00’’S, 40°27’00’’W, 1000m, 14 April 1999, (fl.), L. P . Queiroz et al. 5516 ( HUEFS, UB); ib., Trilha da Serra da Jacobina para Cachoeira da Viúva , 11°09’30.6”S, 40°29’52.6”W, 688m, 04 August 2017, (fl., fr.), A. O . Souza 2216, 2217, 2218 ( UB, UFG); Morro do Chapéu , ca. 6 km S . of town of Moro do Chapéu , 1100m, 18 February 1971, (fl.), H. S . Irwin et al. 32481 ( F, L / U, NY); ib., 34 E of Morro do Chapéu, along Higway BA-052, Chapada Diamantina , 03 April 1976, (fl.), G . Davidse & W. C . D’Arcy 11877 ( SP); ib., 31 May 1977, (fl., fr.), A . Fernandes & Matos s. n. ( EAC3299 ); ib., 11°33’00’’S, 41°08’00’’W, 12 May 1978, (fl.), J. S . Silva 533 ( SP); ib., estrada Bonito – Morro do Chapéu a 10 km de Morro do Chapéu , 18 May 1982, (fl., fr.), A . Fernandes & Matos s. n. ( EAC 11403); ib., rodovia Lage do Batata-Morro do Chapéu , km 66, 11º27’S, 41º07’W, 1000m, 28 June 1983, (fl.), L . Coradin et al. 6231 ( CEN); ib., BR 242 km 146, 11º35’00’’S, 41º13’00’’W, 1000m, 07 September 1994, (fl., fr.), G. P . Silva et al. 2715 ( CEN, INPA); ib., estrada para Utinga, ca. 5 km de Morro do Chapéu , 11°35’51’’S, 41°09’48’’W, 1000m, 18 July 2001, (fl.), V. C . Souza et al. 26391 ( ESA); ib., 11°35’52’’S, 41°09’48’’W, 1080 m, 28 January 2005, (fl.), J . Paula-Souza et al. 4851 ( ESA); ib., ca. 10 km a leste de Morro do Chapéu, saída para Salvador , 11°35’3.2”S, 41°05’42.5”W, 936m, 03 August 2017, (fl.), A. O . Souza 2208 ( UB); Senhor do Bonfim, Serra da Jacobina , W . of Estiva, ca. 12 km N . of Senhor do Bofim on the BA 130 to Juazeiro, 10°18’00”S, 40°15’00”W, 1100m, (fl.), R. M . Harley 16556 ( L / U); ib., Serra de Santana , 26 December 1984, (fl.), G. P . Lewis et al. 36646 ( F, SPF); Umburanas, 3 km, NW of Lagoinha (5.5 km SW od Delfino) on the side road to Minas do Mimoso , 10°22’00”S, 41°20’00”W, 950m, 04 March 1974, (fl., fr.), R. M . Harley 16652, 16702 ( L / U) .