Chamaecrista juruenensis (Hoehne) Irwin & Barneby (1982: 660)

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 : 55-58

13. Chamaecrista juruenensis (Hoehne) Irwin & Barneby (1982: 660) . ≡ Cassia juruenensis Hoehne (1922: 13) . Type:— BRAZIL. Mato Grosso: Juruena, May 1909, (fl.), F.C. Hoehne 1841 (holotype R000027420!). (Figs. 25 and 26)

= Chamaecrista conferta var. gurgueiana Fernandes& Nunes (2000: 4) . Type:— BRAZIL. Piauí: Bom Jesus , in cerradão 700m, Serra de

Uruçuí, 05 June 1998, (fl.), A. Fernandes s. n. (holotype EAC 26676!, isotype NY 452025!) Syn. nov .

Shrubs or subshrubs perennial, 1.5–3 m tall, erect, with long branches. Root nodules absent. Branches crown or whitish due to trichome density; white, non-viscous villous, including stipules, petiole, rachis and leaflet faces; non-exfoliating bark. Stipules 2–3 × 0.4–0.5 mm, linear, persistent or deciduous.Leaves alternatespiral,regularly distributed along the stem, plagiotropic or ascending; petiole (1) 1.2–2.5 cm long; rachis 0.7–1.5 cm long; leaflets 2 pairs, (1.5–)2–4.7 × 1.3–3 cm, distal pair slightly larger than proximal pair, largely elliptical, oboval or suborbicular, apex emarginate or rounded, base rounded or oblique at distal pair, chartaceous to papyraceous, opaque green or white, sometimes vinaceous along the main vein; margin entire, flat or revolute, ciliated or not; secondary veins 4–8 pairs, inconspicuous and imprinted on both sides. Leafy appendix inter-petioluleabsent.Racemes 10–25 cm long, peduncle 1–2 cm long, 10–23 flowers, lax, terminal, erect with straight axis, setulose-viscous and villous, including pedicel, external surface of bracts, bracteoles and sepals. Bracts 2–4 × 0.4–1 mm, lanceolate, persistent. Bracts 1–2 × 0.5 mm, similar to bracts. Buds 0.8–1.3 × 0.6–1 cm, ellipsoid, apex obtuse or rounded.Flowers 1.8–3.5 × 1.5–3 cm; pedicel 1.7–3 cm long; sepals 1.2–1.4 × 0.4–0.7 mm, elliptical or largely elliptical, apex obtuse, reddish-green externally; 4 flat oboval or oblongoboval petals and 1 falcate-curled inner petal, 2–2.3 × 0.7–1.2 cm, yellow; stamens 10.5– 6 mm long, anthers not barbulate; ovary 2.5–4 × 1.5 mm, setulose-viscous and puberulent; style 1.5–2 cm long, curved in upper third, glabrous. Legumes 3.4–4.5 × 0.6–0.9 cm, linear-oblong, setulose-viscous and sparsely puberulent, dark brown. Seeds 4–6, 7–7.5 × 5–5.5 mm, oblong or obovoid, blackened.

Geographical distribution and habitat:— Chamaecrista juruenensis occurs in the states of Bahia, Mato Grosso, Maranhão, Piauí, Tocantins, it is a new reference for Pará, and excluded from Goiás, since the specimens of this last state come from regions that today comprise the state of Tocantins (Fig. 39 A). It grows in typical savannahs or savannas in preferentially sandy soils between 245 and 850 m altitude .

Flowering and fruiting:—It flowers and fruits from March to December, with the flowers and fruits being more intense between May and July.

Conservation status: —Taxon Least Concern (LC) regarding its conservation given its wide distribution (ca. 700,000 km 2), forming large populations (more than 30 mature individuals) and for occurring in preserved environments and areas protected by laws.

Histórico e ajustes taxonômicos:— Cassia juruenensis was described by Hoehne in 1922, positioned in C. sect. Absus subsect. Absus ser. Absoideae by Irwin & Barneby (1978), and transferred to Chamaecrista by Irwin & Barneby (1982).

Fernandes & Nunes (2000) described Ch. conferta var. gurgueiana based on an own collection (Fernandes s. n. EAC26676) from the state of Piauí. These authors argued that his new variety differed from the others of Ch. conferta ( Bentham 1870: 142) Irwin & Barneby (1982: 658) for having densely villosule branches and leaflets, while the others were glabrous. Analyzing specimens of Ch. conferta var. gurgueiana , collecting and observing populations of the same in their areas of occurrence, we concluded that variety actually comprises a variation of Ch. juruenensis .The type of Ch. conferta var. gurgueiana is completely similar to that of Ch. jurenensis , especially in its diagnostic characters (branches and leaflets with dense villosule and whitish indumentum, leaves with prominent main veins and vinaceous on the abaxial surface). Therefore, we subordinate Ch. conferta var. gurgueiana as a synonym of Ch. jurenensis . This decision is also supported by the phylogenetic results of Souza et al. (2021).

Characterization and morphological relationships: — Chamaecrista juruenensis may vaguely resemble Ch. roncadorensis by the leaves with leaflets firmly chartaceous with prominent and vinaceous main vein on the abaxial face and by the general appearance of the inflorescences and flowers, but it differs from Ch. roncadorensis for having a subshrub or upright shrub habit; branches and leaflets commonly densely villosule with a whitish appearance and less frequently glabrous, leaves ascending or not and inflorescence erect (vs. creeping or decumbent subshrub habit; branches and leaflets commonly glabrous and less frequently villous; leaves facing the same side and oriented in the same direction opposite to the ground and suberect inflorescence in Ch. roncadorensis ).

In populations from Jalapão we noticed that individuals of Ch. juruenensis have dimensions of branches, leaflets and flowers and density of indumentum greater than those admitted in the typical concept of the species, which probably reflect the environment where they are located. The populations of Bahia, Piauí and Maranhão, on less sandy soils than those of Jalapão, are more conservative in their characters, as they present individuals, in general, with ascending leaves with smaller leaflets and thin or dense villus-white indumentum always present.

Specimens examined:— BRAZIL. Bahia, Baianópolis, rodovia 242, entroncamento Baianópolis km 6, 12º11’S, 44º31’W, 670m, 01 September 1994, (fl., fr.), G. P . Silva 2506 ( CEN, HUEFS); Barreiras, Rod. BR-020, 30 km O de Barreiras , 12 July 1979, (fl., fr.), G . Hatschbach 42304 ( EAC, MT, XAL); ib., a 20 km de Barreiras , 17 May 1982, (fl., fr.), A . Fernandes & Matos s. n. ( EAC 11367); ib., estrada para o aeroporto de Barreiras , 11 June 1992, (fl.), A. M . Carvalho et al. 4051 ( F, NY); Cocos, ca. 18 km de Cocos, Riacho do Meio , 14°15’25”S, 44°40’29”W, 520m, 16 May 2001, (fl.), F . França et al. 3601 ( IBGE); Correntina, Fazenda Jatobá, 27 June 1992, (fl., fr.), M . Aparecida et al. 1422 ( UB); ib., Espigão Mestre, Rod. BR-349, 64 km L do trevo com a Rod BR-020, 16 May 2000, (fl., fr.), G . Hatschbach et al. 71227 ( ESA); ib., Fazenda Jatobá-Reserva Biológica Fazenda Jatobá, 14°01’00.7’’S, 45°58’11.7’’W, 850m, 29 July 2004, (fl., fr.), M. L . Fonseca et al. 5608 ( CEN, EAC); ib., BR-349, ca. 50 km a E do trevo da Br-020 com a Br- 349 em direção a Correntina , lado esquerdo da rodovia, 13°39’39.9”S, 45°45’14.4”W, 799m, 08 May 2017, (fl., fr.), A. O . Souza et al. 2045 ( UB, UFG); São Desidério, Estrada para a Fazenda Grande Oeste e Faz. Riacho Doce, ca. 15 km da entrada da BR-463, 12°28’43.4”S, 45°08’54.2”W, 731m, 14May 2017, (fl., fr.), A. O . Souza et al. 2096, 2097 ( UB, UFG) . Maranhão: Barra do Corda, Fazenda Chapada , 10 November 2002, (fr.), M . Andrade & B. S . Cavada s. n. ( EAC0032206 ); Carolina, a 25km de Carolina , estrada Transamazônica , 13 November 1979, (fl.), P . Martins & E . Nunes s. n. ( EAC0007391 ); Grajaú , 21 December 1977, (fr.), A . Fernandes & Matos s. n. ( EAC0003633 ); Lajeado, entre Lajeado e Grajaú ( Transamazônica ), 05 August 1978, (fl., fr.), A . Fernandes & Matos s. n.( EAC0004061 ); Timon, estrada para Bemposta , 27 July 1979, (fl., fr.), A . Fernandes et al. s. n.( EAC0006824 ) . Mato Grosso: Barra do Garças, 26 km along new road NNE of village of Xavantina, 6, 5 km due NNW of Royal Society-Royal Geographic Society Base Camp., 12°51’00”S, 51°45’00”W, 06 Setember 1968, (fl., fr.), G . Eiten & L. T . Eiten 8590 ( UB, SP); Ribeirão Cascalheira, ca. 270 km N . of Xavantina, close to the Xavantina – São Félix road, 11 June1968, (fl.), J. A . Ratter et al. 1708 ( IAN, NY, UB); São Félix do Araguaia, 1 km ao sul de São Félix do Araguaia , 11°37’00”S, 50°39’00”W, 230m, 14 July 1994, (fl.), G. P . Silva & R. S . Kraft 2404 ( CEN, INPA). Pará: Cachimbo, Gleba Curuaé, 08°45’00”S, 54°45’00”W, July 2005, (fl.), M . Sobral et al. 9780 ( BHCB) . Piauí: Baixa Grande do Ribeiro, Estação Ecológica de Uruçuí-Una, Alto da Vereda do Meio , 08°54’36”S, 44°59’54.3”W, 384m, 23 May 2000, (fl.), R . Barros et al. 706 ( TEPB); Barreiras do Piauí, 18 July 1981, (fl.), A . Fernandes & V . Rodrigues s. n. ( EAC 10601); ib., 19 July 1981, (fl.), A . Fernandes & V . Rodrigues s. n. ( EAC 10613); ib., APA-Estadual Fazenda Fortaleza ( Chapada das Mangabeiras ), 24 August 1996, (fl., fr.), A . Fernandes et al. s. n. ( EAC 24262); Curimatá , APA de Curimatá , 10 June 1999, (fl.), A . Fernandes & E . Nunes s. n. ( EAC 28309); Currais, Rodovia PI-392, de Bom Jesus em direção a ESEC Uruçui-Una , 08°49’0.7”S, 44°40’51.6”W, 620m, 21 July 2017, (fl., fr.), A. O . Souza & L. L. C . Antunes 2171, 2172, 2173 ( UB, UFG); Prata, Estação Ecológica de Uruçuí-Una , 17 May 1984, (fl.), A . Fernandes s. n. ( EAC 12587); Ribeirão Gonçalves, Estação Ecológica , Uruçuí-Una , 04 September 1981, (fr.), A . Fernandes & V . Rodrigues s. n. ( EAC 10733); ib., 23 July 1983, (fl., fr.), A . Fernandes s. n. ( EAC 12126) . Tocantins: Almas , RPPN da Fazenda Minnehaha, ca. 70km a SW da cidade de Almas , 11°08’18.4”S, 47°07’20.3”W, 12 August 2004, (fl.), R. C . Mendonça et al. 5706 ( ESA); Angico, Bacia do Araguaia sub-bacia do rio Piranhas , 06°19’34”S, 47°56’04”W, 226m, 20 May 2010, (fl.), F. C. A . Oliveira et al. 2370 ( EAC, IBGE); Araguaína, ca. 2 km N . of Araguaína , 300m, 13 March 1968, (fl.), H. S . Irwin et al 21145 ( NY); ib., rodovia Anápolis-Belém, BR-010, km 1097- GO , 12, 12 October 1980, (fl.), L . Coradin et al. 3716 ( CEN); ib., Bacia do Tocantins, sub-bacia Rio Lontra , 07°05’06”S, 48°12’39”W, 219m, 03 August 2010, (fl.), R. F . Haidar et al. 1332 ( EAC, HUTO); Filadélfia, west of Filadélfia in Serra de Mamoneira , 02 August 1964, (fl., fr.), G. T . Prance & N. T . Silva 58507 ( F, L / U, NY, UB); ib., 07°26’00”S, 47°40’00”W, 270m, 07 July 2005, (fl.), M. F . Simon 655 ( CEN); Mateiros, Jalapão, estrada Mateiros-São Félix do Tocantins, aproximadamente 9 km de Mateiros, 10°28’23.9’’S, 46°27’17’’W, 563m, 20 September 2012, (fr.), L. M . Borges et al. 860 ( CEN); Mateiros, estrada para Mateiros antes Galhão , 10°36’28.1”S, 46°09’54.4”W, 672m, 18 July 2017, (fl., fr.), A. O . Souza & L. L. C . Antunes 2151, 2152 ( UB, UFG); ib., Jalapão, estrada de Mateiros para os Fervedouros, 10°28’6.9”S, 46°27’26.7”W, 506m, 19 July 2017, (fl., fr.), A. O . Souza & L. L. C . Antunes 2159, 2160, 2161 ( UB, UFG) Miracema, estrada Lajedo Miracema, margem direita área sob solo arenoso, 09 o 36’42.6’’S, 48 o 24’58.8’’W, 245m, 20 June 2009, (fl., fr.), E. R . Santos & A. C . Pereira 1752 ( UFG, HUTO); Ponte Alta do Bom Jesus , divisa Bahia – Tocantins, km 11, 11°58’00”S, 46°20’00”W, 660m, 09July 1993, (fl.), G . Pereira-Silva et al. 1393 ( CEN) .