Ouratea crassinervia Engl., 1876

John Teixeira, Luíza, Araújo, Michelly de Deus Felipe, Deccache, Lara Serpa Jaegge & Fraga, Claudio Nicoletti de, 2025, When nomenclature and morphology unravel an enigma: the true identity of Ouratea crassinervia (Ochnaceae), Plant Ecology and Evolution 158 (2), pp. 237-247 : 237-247

Ouratea crassinervia Engl. ( Engler 1876: 337)

Figs 1 , 2 , 3 A – F , 4

Ochna crassinervia Kuntze ( Kuntze 1891: 106)

Type.

BRAZIL – Rio de Janeiro • Itapacorá [= Itaboraí]; s. d.; s. col. s. n.; lectotype (designated here): W! [ W 0017373 ] . BRAZIL – Rio de Janeiro • Itapacorá [= Itaboraí]; s. d.; s. col. s. n.; remaining syntypes: W! [ W 0017627 , W 0017628 ], F! [no. 875052] .

Description.

Treelet 0.3–2 m tall; stem erect, unbranched, apical bud aborting after flowering, lateral bud developing afterwards (Chamberlain’s Model), glabrous, dark brown, bark fistulose, when young smooth, when mature striate. Stipules 12–15 × 6.5–8 mm, caducous, triangular, margins revolute. Leaves spirally arranged to subverticillate, clustered in groups of 6–22 at the apex of the stem; petiole 5–12 mm long, canaliculate; blade oblanceolate, 23–45 × 5.7–11.7 cm, chartaceous, base rounded, margins entire at the base and serrate towards the apex, slightly revolute and undulate, apex acute to attenuate, adaxial and abaxial surfaces dark green, glabrous; venation eucamptodromous, midvein sulcate on adaxial surface, prominent on abaxial surface, green, secondary veins 5–12, impressed on adaxial surface, prominent on abaxial surface, green, tertiary veins inconspicuous, glabrous, light-green. Inflorescence terminal, 19–29 cm long, thyrsoid, erect, congested, the axis rugose with punctate white dots, glabrous, set with groups of 2–9 flowers in depauperate uniparous cymes of the bostryx type; basal bracts imbricate, sterile, unequal, triangular, 6.4–8.6 mm long, similar to the stipules, persistent, dark brown; peduncle bracts 3 per node, alternate, sterile, unequal, narrowly triangular, 7.8–10.4 mm long, persistent, brown; rachis bracts solitary, alternate, inserted at the base of the bostryx, falcate, 8.8–11.5 mm long, persistent, brown; bostryx congested, rachis inconspicuous, pedicel articulation 2.4–5.2 mm long, cylindrical, bostryx bract 1 per branch, narrowly triangular to linear, 2.2–2.9 mm long, persistent, reddish-brown. Flowers with 1–2 bracteole per flower, narrowly triangular to linear, 1.7–2.4 mm long, early caducous, reddish-brown; pedicels 7.6–11 mm long above the bostryx, straight to curved, papillate; sepals 5, imbricate, elliptic to obovate, 7.1–9.2 × 1.6–2.2 mm, concave, base rounded, margin hyaline, apex acute, adaxial surface papillate, reddish, abaxial surface glabrous, thicker in the middle, orange-yellowish; petals 5, obovate, 10–12 × 5–6 mm, occasionally thicker at the base and along the central vein, base attenuate to unguiculate, margin entire, apex reflexed and rounded, glabrous, yellow; stamens 10, arranged in a circle around the ovary, anthers erect, sessile, sigmoid, 5.5–6.4 mm long, transversely rugulose, poricidal, yellow; gynophore columnar, 0.8–1 × 0.8–1.1 mm, thickening near the apex, salmon pink; gynoecium superior, 5 - carpellate, fertile units 5, 0.9–1.2 × 1.2–2 mm, oblate, salmon pink; style 1, erect, filiform, gynobasic, 0.7–0.9 mm long, stigma punctiform, salmon pink. Fruit with carpophore 5.6–11.5 × 3.9–10.6 mm, oblate, rugose, when immature greenish, salmon pink at the base, when mature red; mericarp 1, rarely 5, ellipsoid or obpyriform, erect or obliquely disposed on the carpophore, 10.4–12.3 × 5.2–6.4 mm, pericarp thin, rugose, when immature greenish, when mature brownish; seed 1, 8.8–10.5 × 5.0– 5.6 mm, testa membranous, slightly rugose.

Distribution and ecology.

Ouratea crassinervia is known from 25 collections from low Atlantic Forest in northeastern Rio de Janeiro state, southeastern Brazil (Fig. 2 ). It has been collected in areas 40–50 m above sea level, with flowers from November to January and fruits from December to March.

Preliminary IUCN conservation assessment.

Ouratea crassinervia never had its conservation status assessed since the establishment of the IUCN criteria. The species has been recorded so far by 25 collections from 11 locations (sensu IUCN 2012), resulting in an estimated extent of occurrence (EOO) of 2,875 km 2 and a minimal area of occupancy (AOO) of 60 km 2 (AOO based on IUCN default cell width 2 km = 4 km 2). These numbers fall within the limits for Endangered (EN) under the criteria B 1 (EOO <5,000 km 2) and B 2 (AOO <500 km 2). It has registered occurrences within two protected areas in neighbouring municipalities, representing three locations (sensu IUCN): Poço das Antas Biological Reserve, Silva Jardim (5,000 ha) and União Biological Reserve, Casimiro de Abreu (5,080 ha). Although the number of locations where the species occurs is just above the limits for Endangered and Vulnerable, the natural habitat is also severely fragmented. Furthermore, they are threatened by disorderly real estate speculation in urban areas and prone to the effects of human activity like livestock breeding and agriculture, which can lead to a continuous decline in the extent of occurrence and quality of habitat of the species as well as the associated plant diversity in the region. For this reason, Ouratea crassinervia is preliminary assessed as Endangered: EN B 1 ab (i, iii) + 2 ab (i, iii).

Additional material examined.

BRAZIL – Rio de Janeiro • Andayassu [Mun. Casimiro de Abreu]. Restinga de Mauá et Andayassu ; s. d.; fl.; A. F. M. Glaziou 18980; P • Andayassu [ Mun. Casimiro de Abreu ]; 28 Dec. 1891; fl.; A. F. M. Glaziou 12534; P ! • Mun. Casimiro de Abreu, Reserva Biológica União, Br- 101, ca 3 km após a sede do Parque em direção a Campos do Goytacases, estrada a direita em frente ao cemitério de Rocha Leão. Estrada da Macuca, rumo a Rio das Ostras, trilha a ca 2 km da estrada da Macuca, acesso a direita. Floresta Ombrófila Densa ; 22°26’10.9”S, 42°01’34.2”W; fl.; 9 Jan. 2012; A. Lobão et al. 1798; RB!, SPF ! • Mun. Cachoeiras de Macacú ; 22°30’46”S, 42°52’10”W; 21 Sep. 2023; fl.; T. Fernandes 1506; NIT!, RB ! • Mun. Barra de São João. Área litorânea ; 1969; fl.; J. P. Santos s. n.; RB ! • Mun. Guapimirim. Fazendas Consorciadas SA., área de estudo da Embrapa Agrobiologia, acesso pela estrada da Parada Modelo ; 22°33’S, 42°51’W; 14 Feb. 2009; fr.; R. Borges et al. 924; RB ! • Mun. Macaé, Cabiunas, Terminal Cabiúnas-Petrobras. Parcela Monitoramento e Fenologia ; 22°17’09”S, 41°43’59”W; 41 m; 9 Mar. 2013; fr.; A. P. Fontana et al. 7490; MBML ! • Mun. Magé, Restinga de Mauá ; 15 Nov. 1874; A. F. M. Glaziou 7567; R ! • Mun. Magé, ca 3 km ESE de Santo Aleixo ; 22°35’S, 43°02’W; 50 m; 2 Nov. 1983; fl.; R. Guedes & L. P. Gonzaga 549; RB ! • Mun. Magé, ca 3 km ESE de Santo Aleixo ; 22°35’S, 43°02’W; 25 Nov. 1983; fl.; R. Guedes & L. P. Gonzaga 566; RB ! • Mun. Magé, ca 3 km ESE de Santo Aleixo ; 22°35’S, 43°02’W; 17 Dec. 1983; fl., fr.; R. Guedes & L. P. Gonzaga 597; RB ! • Mun. Magé, ca 3 km ESE de Santo Aleixo ; 22°35’S, 43°02’W; 14 Jan. 1984; fr.; R. Guedes & L. P. Gonzaga 618; RB ! • Mun. Magé, ca 3 km ESE de Santo Aleixo ; 22°35’S, 43°02’W; 16 Feb. 1984; fr.; R. Guedes & L. P. Gonzaga 672; RB ! • Mun. Silva Jardim, Reserva Biológica de Poço das Antas, mata secundária ; 24 Oct. 1979; fl.; D. Araujo 3368; RB ! • Mun. Silva Jardim, Reserva Biológica de Poço das Antas, trilha para Fazenda Portuense, prox. estrada do cajueiro ; 22°30’S, 42°19’W; 20 m; 28 Nov. 1992; fl.; H. C. Lima et al. 4543; RB!, MBM, CEPEC, SPF, MBML ! • Mun. Silva Jardim, Reserva Biológica de Poço das Antas, Trilha Portuense , direita; 22 ° 30 ’ / 22°33’S, 42 ° 15 ’ / 42°19’W; 9 Dec. 1993; fl.; C. Luchiari et al. 183; RB ! • Mun. Silva Jardim, Reserva Biológica de Poço das Antas, estrada para Juturnaiba, trilha a 1 km do portão da REBIO à direita ; 25 Feb. 1994; fr.; A. Piratininga et al. 49; RB ! • Mun. Silva Jardim, Reserva Biológica de Poço das Antas, trilha Rodolfo Norte ; 22°31’36”S, 42°18’07”W; 18 m; 22 Dec. 2014; N. G. Bordon & C. Bordon 14; UEC • Mun. Silva Jardim, Reserva Biológica de Poço das Antas, trilha principal ; 22°31’50”S, 42°17’59”W; 59 m; 11 Dec. 2021; C. N. Fraga et al. 4110; RB ! • Mun. Silva Jardim, Reserva Biológica de Poço das Antas, trilha para o Rio Pau Preto, ca 1 km após a porteira da REBIO Poço das Antas ; 22°30’54”S, 42°16’24”W; 30 m; 2 May 2023; D. Nunes & P. Feliz et al. 1445; RB ! • Mun. Silva Jardim, Reserva Biológica de Poço das Antas, estrada para Juturnaíba, ca 2 km após porteira da estrada que leva para Barragem de Juturnaíba ; 22°32’52”S, 42°17’55”W; 3 May 2023; fr.; P. Feliz & D. Nunes 444; RB ! • Mun. Silva Jardim, Reserva Biológica de Poço das Antas ; 22°32’36.4”S, 42°18’02.7’’W; 40 m; 7 Dec. 2023; fl.; L. John et al. 212; RB !.

Notes.

Three specimens were found in W, and one in F whose labels match the protologue information, such as collection locality. The material from F has a determination label for Ouratea crassinervia , the locality of Itapacora, and a question mark after Pohl’s name. Also, there is a note by Dwyer indicating that it is part of the type material of Ouratea curvata (which the author places as a synonym of O. crassinervia ). On the W specimens, the identification label says Ouratea curvata (A. St. - Hil.) Engl. ex Dwyer , apparently written by Engler in his handwriting ( Burdet 1974). In addition, two of these W samples (barcodes W 0017627 and W 0017628) have labels indicating pages 1 / 2 and 2 / 2, suggesting that they are from the same collection. The other W sample (barcode W 0017373) has no information to differentiate it from the others, but even so, it is not possible to guarantee that they represent the same collection. Moreover, we do not know for sure which of the samples represents Sellow’s gatherings (Sellow 220 and 298), as this information has been lost over time. We have chosen the sample with barcode W 0017373 as the lectotype, and the other samples may be regarded as remaining syntypes.

The synonymy adopted in Flora e Funga do Brasil (2024), with Ouratea crassinervia being a synonym of O. curvata , is an error that started with Engler (1876) when he mentions O. curvata in the identification key with the number “ 41. (56.) ” and in the referred position of the species he describes O. crassinervia as a new species, based on a type of its own, without mentioning O. curvata or its presumed basionym, Gomphia curvata A. St. - Hil. , as evidenced by Dwyer (1944). Thus, the species Gomphia curvata A. St. - Hil. , described from “ Carahype ” (probably Jacaraípe, Serra municipality) near the coast of Espírito Santo state ( Saint-Hilaire 1825), does not have a valid new combination in Ouratea in Flora Brasiliensis ( Engler 1876). This combination was only realized by Dwyer (1944), who then also erroneously synonymized O. crassinervia and O. costaricensis Standl. under O. curvata .

Based on the synonymy adopted by Dwyer (1944), the name Ouratea curvata has been used in Central America ( Dwyer 1967; Castillo-Campos and Medina Abreo 2014). However, Morales (2007), based on the Flora of Panama ( Dwyer 1967), considers that Dwyer’s (1944) concept is misconceived and does not reflect the identity of Gomphia curvata , and thus adopts O. crassinervia for the Flora of Costa Rica.

Morphologically, O. crassinervia and related species have a dracenoid habit, which can be defined as that of plants with leaves grouped at the apex and with congested spiral phyllotaxis. In addition to it, there are six other species in the genus with this specific habit, four in Brazil, with three in the Atlantic Forest ( Ouratea cauliflora Fraga & Saavedra , Ouratea dorata L. Marinho & Amorim , and Ouratea verticillata (Vell.) Engl. ) and one in the Amazon ( Ouratea ramiflora Sastre ), and the other two in Central America ( Ouratea costaricensis , and Ouratea theophrasta (Planch.) Baill. ).

For this group of dracenoid plants, O. crassinervia can be easily distinguished by its terminal inflorescence on the sympodium. Still, the plants are not monocarpic due to vegetative growth occurring from a meristem in the axil of one of the distal leaves. Its inflorescence is composed of a main axis (first order) from where a group of articulated pedicels departs. In contrast, for the other dracenoid Ouratea species, the inflorescences are always axillary, cauliflorous, or with small lateral paraclades.

Figures

Figure 1. Species and architectural models of dracenoid Ouratea. A – F. Chamberlain’s Model of O. crassinervia. A. Live plant in the field (with Claudio Nicoletti de Fraga). B. Habit. C. Inflorescence. D. Apex of inflorescence with buds. E. Middle of inflorescence with bostrix in detail. F. Flowers. G, J, L. Leeuwenberg’s Model of O. cauliflora. H, I, K. Leeuwenberg’s Model of O. dorata. G, H. Live plant in the field. I. Lateral branches. J. Lateral branches with inflorescences. K. Flower. L. Lateral branches with paracladia and fruits. M – O. Conner’s Model of O. verticillata. M. Live plant in the field (with Luíza John Teixeira). N. Axillary inflorescence. O. Inflorescence with uniparous cymes. P – Q. Conner’s Model of O. costaricensis. P. Live plant in the field. Q. Fruits. Photos by João Victor Monzoli (A), Claudio Fraga (B – L), Thiago Fernandes (M), Eliana Gressler (N, O), and Lena Struwe (P, Q).

Figure 2. Map showing the geographical distribution of Ouratea crassinervia (black dots) on a layer of land uses and cover with extent of occurrence (EOO) and an indication of the area of occupancy (AOO) in the state of Rio de Janeiro, Brazil.

Figure 3. Architectural models and inflorescence of dracenoid species of Ouratea. A. Chamberlain’s Model. B. Leeuwenberg’s Model. C. Conner’s Model.

Figure 4. Inflorescences in dracenoid species of Ouratea. A. Structure of inflorescence of dracenoid Ouratea (in grey when several inflorescences emerge from the same point). B. Detail of the bostrix of O. crassinervia: a, basal bracts of the bostryx; b, bostryx bract; c, bracteole; d, rachis of the bostryx (inconspicuous); e, pedicel articulation; f, floral pedicel; g, buds or flowers.