Chamaecrista pachyclada ( Harms 1924: 126 ) Irwin & Barneby (1982: 655)

Mendes, Thainara Policarpo, Souza, Alessandro Oliveira De & Silva, Marcos José Da, 2021, Taxonomic review of Chamaecrista sect. Absus subsect. Absus ser. Paniculatae (Benth.) H. S. Irwin & Barneby (Leguminosae, Caesalpinioideae), Phytotaxa 495 (1), pp. 1-64 : 42-46

8. Chamaecrista pachyclada ( Harms 1924: 126) Irwin & Barneby (1982: 655) . ≡ Cassia pachyclada Harms (1924: 126) . Type: — BRAZIL. Goiás: Chapadão Grande, zwischen Guariroba und Rio Torto, 1984/5, fl., A Glaziou 20979 (lectotype designated by Irwin & Barneby [1978: 155] P!; isolectotypes: C 10012000!, F0057630F!, G00371007!, K000555585! LE00002359!, S10-8966!). Figs. 25 and 26

Shrubs 50– 1.4 m tall, erects, cespitose, not branched. Stem and branches resin-dotted, cylindrical, stem and adult branches dark-brown, stem and young branches yellowish, including external surface of stipules, petiole, rachis, margin of leaflets, face abaxial and adaxial of leaflets, inflorescence axis, external surface of bracts, bracteoles, buds, sepals, ovary and fruits. Stipules 1.5 × 0.4 mm, triangular subulate, persistent. Leaves 3–5.9 cm long, regularly distributed throughout the branches, but more concentrated on the branch terminations, ascending; pulvinus 2–3 mm long, discreetly dilated, striated; petiole 2−3.4 cm long; cylindrical and sulcate above; rachis 0.9–1.6 cm long, cylindrical and sulcate above; interfoliolar segments 1–3.5 cm long; pulvinule 1.9–2.8 mm long; visibly dilated; leaflets 4–6 pairs, coriaceous; blades 1.9–4.8 × 1.3–3.1 cm, elliptic, oval-elliptical, orbicular-oblong, oblong-elliptic, margin glandular-crenulate, plane, surface abaxial and adaxial glabrous, base asymmetrically rounded, apex rounded, discreetly emarginated, with mucron, light green, opaque; venation with, secondary veins 5–6 pairs, greenish yellow. Panicles 17–26.1 cm long, with 8–13 secondary axis, not geminate, terminal, with flowers laxly distributed, erects. Bracts 0.8–1.5 × 0.9–1 mm, deltoid or triangular, apex obtuse, margin entire, greenish yellow, persistent. Bracteoles 0.8–1.3 × 0.6–0.8 mm, ovate, apex acute, light green, margin entire, light green, persistent. Buds 0.6–1.2 mm long, ovoid, green with purplish pigmentation, apex obtuse. Flowers 1.2–3.5 cm long; pedicel 1.7–2 cm long, robust, cylindrical; sepals 1–1.6 × 0.3–0.6 cm, oval-lanceolate, apex obtuse, yellow with purplish pigmentation; petals 1.1– 2.3 × 0.6–2.8 cm, obovate, with the adaxial petal like a standard, one of the inner petals coiled in the androecium; stamens 4–9.2 mm long, filaments 1–1.2 mm long; anthers 3–8 mm long, not mucronulate at apex. Ovary 3–5 × 1–1.2 mm; styles 0.7–1.2 cm long, glabrous. Legume 2.6–3.9× 0.5–0.6 cm, light green to brown, narrow-oblong. Seeds unknown.

Representative specimens examined: — BRAZIL. Federal District: Brasília, ca 1.5 km W de antenas de Radiobras, 15°36’00”S, 48°07’48.0”W, 14 April 1982, (fl.), J . H . Kirkbride Jr. 4718 ( NY, UB); ib., Córrego Barrocão , 15°37’S, 48°09’W, 02 May 1983, (fl.), J . H . Kirkbride Jr. 5280 ( SP, INPA e NY); Cerrado próximo ao CPAC , sentido Sobradinho-Planaltina — DF, 13 July 2000, (fl.), Lídio Coradin & Afrânio 4229 ( CEN); estrada Sobradinho / Brazlândia , 15°40’00”S, 48°06’00”W, 1200 m, 01 April 1992, (fr.), R . D. Vieira et al. 1243 ( CEN); ib., Borda do Parque Nacional de Brasília estrada de terra paralela a DF 430, sentido Brazilândia-Taguatinga , 15°44’11.0”S, 48°03’48.0”W, 882 m, 10 March 2006, (fl.), J . R . Santos, A . C . Amaral, G . A . Moreira et al. 293 ( UB e CEN); ib., estrada para Brazlândia, na beira do Parque Nacional de Brasília , 15°36’19”S, 48°02’13”W, 1254 m, 06 August 2013, (fr.), A . B . Giroldo & R . R . da S. Cruvinel 54 ( CEN) . Goiás: Alto Paraíso de Goiás, Região da Chapada dos Veadeiros, 5 km a oeste de Veadeiros, 14°30’S, 47°30’W, 887 m, 29 April 1956, (fl.), E . Y . Dawson 14721 ( NY). ib., Parque Nacional da Chapada dos Veadeiros, Campo ca. 12 km Sul de Alto Paraíso, 1000 m, 22 March 1969, H . S . Irwin et al 24902 ( NY); ib., Parque Nacional da Chapada dos Veadeiros , 14°09’39.1”S, 47°47’30.2”W, 10 May 2013, (fl., fr.), M . J . Silva 4872 ( UFG), 4867 ( UFG), 4868 ( UFG), 4881 ( UFG), 4880 ( UFG), 4897 ( UFG), 4896 ( UFG), 4863 ( UFG); ib., 19 March 2016, (fl.), T . P . Mendes, J . A . Oliveira 12 ( UFG), 13 ( UFG), 14 ( UFG); Padre Bernardo, Fazenda Engenho Queimado, Área loteada, a maios ou menos 10 km ao Sul de Brazlândia , 15°43S, 48°12’W, 1000 m, 13 November 1990, (fl.), R . F . Vieira, S . R . Ramos & A . L . Salas 589 ( CEN) .

Distribution and ecology: —Endemic species of Brazil (Goiás and Distrito Federal), (Fig. 27D). It lives in the cerrados típicos and cerrados rupestres (Figs. 1C, D and G), campos sujos and campos limpos on flat stretches or hillsides or hills, and also on roadsides at altitudes ranging from 882 to 1200 meters.

Flowering and fruiting: —It blooms and bears fruit from March to August.

Etymology: —The specific epithet “ pachyclada ” results from the Greek words “pachy” which means thickened or enlarged and “clados” which means branches, and therefore alludes to the thickened branches of the species.

Conservation status: — Chamaecrista pachyclada covers an area of extension of 9,441 km 2 occurring at random and forming populations with few individuals (up to 25). Therefore, it is here considered as Vulnerable (VU, criterion B1, subcriteria b i, ii, v) in terms of its conservation. We emphasize that some individuals of this species occur in protected areas such as the Chapada dos Veadeiros National Park, while others grow up in environments disturbed by anthropic intervention and with a certain level of habitat decline, such as, roadsides.

Morphological relationships and characterization: —Species characterized by the predominantly shrubby and cespitose habit from a developed underground system, presence of blackish resinous spots in the petiole, rachis, leaflet margin, axis of inflorescence, sepals and ovary; leaves with 4–6 pairs of leaflets, predominantly orbicular or oblongelliptical with a crenulated margin and reddish and conspicuously viscous fruits. Due to the dots and the crenulated margin leaflets, it is similar to Ch. crenulata . The relationships between both species were discussed in comments of Ch. crenulata .