Chamaecrista campestris 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 : 30-33

7. Chamaecrista campestris Irwin & Barneby (1982: 661)

≡ Cassia camporum Bentham (1840: 79) .

Type:— BRAZIL. Mato Grosso: Rio Pardo, e slope of Sera de Maracujá , October 1826, (fl.), L. Riedel 584 (holotype LE00002296 ! (sheet 1/2), LE00002297 ! (sheet 2/2) , isotypes LE00002299 ! LE00002298 !, US00001407 !) . (Figs. 13 and 14)

= Cassia hispidula var. oblongifolia Chodat & Hassler (1904: 825) . Type:— PARAGUAY. “ in altoplanitie pr. flumen Corrientes ”, December,(fl., fr.), E. Hassler 5842 (holotype G00170867 ! (sheet 1/4), G00170868 ! (sheet 2/4), G00170869 ! (sheet 3/4), G00170870 ! (sheet 4/4), isotypesBM000545020!, F0057575F!, GH00053174!, HU00053174! K, MPU023758!, NY01529146!, P00836020!, P00836021!, S-R-8820!, UC940687!).

Subshrubsperennial, 50–80 cm tall, erect, densely branched immediately above the ground. Root nodules absent. Branches brown when mature or yellowish-green when young, both setulose-viscous and puberulent including stipules, petiole and rachis; non-exfoliating bark. Stipules 1.2–2 × 0.4–0.5 mm, lanceolate, persistent. Leaves alternate spiral, regularly distributed, plagiotropic; petiole 0.8–1.5(2) cm long; rachis 5–8(10) mm long; leaflets 2 pairs, 0.7–1.7(2) × 0.5–1 cm, distal pair slightly larger than proximal pair, oblong-elliptical, elliptical, oblong or oblong-oboval, apex obtuse or slightly emarginate, asymmetrical base in the distal pair and cuneate or rounded in the proximal pair papyraceous, concolorous, light green, puberulent on both sides, setulose-viscous along the main vein and close to the margin on the abaxial surface; margin entire, flat, sometimes revolute, ciliate; secondary ribs 4–6 pairs, inconspicuous and imprinted on both sides. Leafy appendix inter-petioluleabsent. Racemes (4)6–10(18) cm long, sessile or with peduncle 0.6–1 cm long, 15–23 flowers, congested, terminal, erect with straight axis, densely setulose-viscous and villous, including pedicel, external surface of bracts, bracteoles and sepals. Bracts 2–4 × 0.5–1 mm, triangular, persistent. Bracteoles 1–2 × 0.5 mm, lanceolate, persistent. Buds 6–10 × 4–6 mm, ovoid or ellipsoidal, apex obtuse or acute. Flowers 1.5–2 × 1.2–1.8 cm; pedicel 4–8 mm long, straight and ascending even when fruited; sepals 7–10 × 2.5–3.5 mm, elliptical, apex acute or obtuse, reddish-green externally; 4 flat oboval or suborbicular petals and 1 falcate-curled inner petal, 1.2–1.7 × 0.7–0.9 cm, yellow; stamens 10, 4–6 mm long, anthers not barbulate; ovary 3–4 × 1 mm, setose-viscous and villous; style 1–1.3 cm long, curved in upper third, glabrous. Legumes 4–5 × 0.8–1.1 cm, linear-oblong, setulose-viscous and puberulent, brown. Seeds 5–6, 5–6 × 3.4–3.5 mm, obovoid, blackened.

Etymology: —epithet probably designated by the type collection of the species having been collected in grassland vegetation.

Geographical distribution and habitat:— South American species occurring in Brazil (Goiás, Mato Grosso, Mato Grosso do Sul, Minas Gerais and São Paulo) and Paraguay (Fig. 38A). It grows in thin or typical savannas on clayey or sandy soils between 400 and 1000 meters of altitude.

Flowering and fruiting:—The species has a record of flowers practically all year round, but it is in January and February that its flowering is more intense.

Conservation status: — Chamaecrista campestris has Least Concern (LC) conservation status due to its long Range of Occurrence (ca. 1,142,132 km 2), forming populations with more than 60 mature individuals, occurring in areas protected by laws such as the Chapada dos Guimarães National Park in the state of Mato Grosso.

Taxonomic history:— Chamaecrista campestris was described as Cassia camporum by Bentham in 1840 based on the L. Riedel 584 collection from the state of Mato Grosso. Chodat & Hassler in 1904 described Cassia hispidula var. oblongifolia based on a specimen from Paraguay collected by the second author under the number E. Hassler 5842. Irwin & Barneby (1978) synonymized Cassia hispidula var. oblongifolia in Cassia camporum , thus expanding its distribution and morphological variation and without commenting on what made him admit such a decision. Four years later ( Irwin & Barneby 1982) the species had its epithet “ camporum ” changed to “ campestris ” when it was transferred to the genus Chamecrista, as the epithet camporum was already occupied under Chamaecrista camporum Greene (= Ch. fasciculata ).

Characterization and morphological relationships: — Chamaecrista campestris is an easily recognizable species and is not confused with any other species of the subsection Absus , especially when fertile, as it has an erect and cespitose subshrub habit, racemes with a spiciform aspect due to the short pedicelled flowers (pedicle 4–8 mm long). Associated with this, the species has setulose-viscous branches, oblong-elliptic leaflets, usually induments with a flat and concolorous margin, ovoid or ellipsoidal yellow-green buds and broad fruits (0.8–1.1 cm wide).

Specimens examined:— BRAZIL. Goiás: Jataí, 102 km S. E . of Caiapônia on road to Jataí, 04 February 1959, (fl., fr.), H. S . Irwin 2579 ( F, NY) . Mato Grosso: Chapada dos Guimarães, Chapada dos Guimarães, 10 January 1989, (fl., fr.), M . Brandão 14747 ( PAMG); ib., 13 February 1976, (fl.), W. R . Anderson 11353 ( F, NY, SP); General Carneiro, BR-070 km 101, entre General Carneiro e Colônia Mururé , 15°33’49”S, 52°57’09”W, 548m, 18 April 2005, (fl.), L. P . Queiroz et al. 10440 ( HUEFS); ib., Parque Nacional Chapada dos Guimarães, Mirante da cidade de Pedra, 15°17’58.1”S, 55°50’25.7”W, 682m, 29 January 2015, (fl., fr.), A. O . Souza et al. 1630 ( UB, UFG); Diamantino, Chapada dos Parecis , ca. 50 km W de Parecis na estrada para campo Novo dos Parecis (MT-160), 14°09’43”S, 57°08’11”W, 573m, 21 April 2005, fl. L. P . Queiroz et al. 10536 ( ESAL); General Carneiro, BR-070, km 101, entre General Carneiro e Colônia Mururé, 15°33’49”S, 52°57’09”W, 548m, 18 April 2005, L. P . Queiroz et al. 10440 ( ESAL, HUEFS); Nova Xavantina , 14 December 1967, (fl.), D. Philcox et al. 3519 ( UB); ib., 12º54’00”S, 51º52’00”W, 22 February 1969, fl. (fr.), E . Onishi et al. 979 ( UB); São José do Rio Claro, Fazenda Cachoeira de Pau , 13°52’00”S, 56°31’00”W, 14 June 1997, (fl.), V. C . Souza et al. 18081-a ( BHCB, ESA, MT, UEC); Sinope , next to BR 163 , Cuiabá-Santarém road, km 831, 16 February 1977, (fl., fr.), J. H . Kirkride 2329 ( INPA); ib., BR 163 , km 807-5, 09 November 1977, (fl.), G. T . Prance et al. 25082 ( L / U, NY) . MATO GROSSO DO SUL, Aquidauana, cerrado de Piraputanga, 19 September 1993, (fl.), W . Resende 1059 ( CGMS); Bandeirantes , Jatobá, 26 August 1973, (fl.), G. G . Hatschbach 32349 ( NY); Bataguassu, estrada entre Bataguassu e Brasilândia , Fazenda Santa Encarnação, 22 November 1992, (fl.), I . Cordeiro et al. 1098 ( HUEFS, NY, SP); Campo Grande, área de Proteção Ambiental dos Mananciais do córrego Guariroba ( APA do Guariroba ), Fazenda Estância D’Casa , margem do córrego Açude , 20°35’06.2”S, 54°23’47.16”W, 552m, 30 January 2008, (fl.), H. C . Vinci- Carlos et al. 151 ( CGMS); Piraputanga, próximo ao Rancho da Oropa , 20°27’51”S, 55°29’08”W, 05 August 2006, (fl.), D. C . Ibrahim 2 ( CGMS, FUEL); Ribas do Rio Pardo , 4km E de Ribas do Rio Pardo, 25 January 1979, (fl.), A . Krapovickas 34374 ( NY); Rio Verde de Mato Grosso, Estância Paraíso, margem de rio, 18°57’10”S, 54°56’10”W, 412m, 04 November 2012, (fl.), D. T . Azevedo et al. 83 ( CGMS, UEC); Sonora, margem da estrada velha para Alto Araguari , logo após ponto sobre o rio, 16°18’35”S, 53°42’29”W, 14 December 2000, (fl.), G. F . Árbocz 7221 ( CGMS, LUSC); Tacuru, rod. MS-295, Fazenda Santa Paula , 18km O de Tacuru, 08 February 1993, (fl.), G. G . Hatschbach et al 58658 ( NY); Terenos , 17 February 1970, (fl., fr.), G. G . Hatschbach 23710 ( NY) . MINAS GERAIS, Araxá, Araxá-Belo Horizonte km 353, 02 February 1979, (fl., fr.), M. B . Ferreira 7759 ( PAMG); João Pinheiro , November 1962, (fl.), G. M . Magalhães 18879 ( NY); ib., rodovia além de João Pinheiro, 16 February 1972, (fl.), E. P . Heringer 12053 ( UB); Lagoa Grande, 82 km S . of Paracatú on road to Patos de Minas , 09 February 1959, (fl.), H. S . Irwin 2610 ( NY); Presidente Olegário , Faz. Vereda Grande, 01 May 1989, (fl.), T. S. M . Grandi 15655 ( BHCB) . São Paulo: Botucatu, 18km north of Botucatu (14km east of São Manuel ), along the S . Manuel-Piracicaba higway, 22°45’00”S, 48°25’00”W, 550m, 13 May, (fl.), I. S . Gottsberger 88 ( NY); ib., distrito do Rubião Junior a 1km a sudoeste do Campus da Universidade , 12 December 1979, (fl.), E . Nagaro 09 ( ESA, F); Itirapina, em cerrado da Estação Experimental do Instituto Florestal e arredores, 12 February 1984, (fr.), H. F . Leitão et al. 15973 ( IBGE) . PARAGUAY. Amambay: Sierra de Amambay, January 1908, (fl.), T . Rojas 10822 ( F, NY); ib., Parque Nacional Cerro Corá, en el cerraod del cerro Trébol , a ± 8 km de la administración, 19 December 1986, (fl.), R. H . Fortunato 941 ( NY) .