Rourea chrysomalla Glaz. ex G. Schellenb., in Engler, Pflanzenreich IV. 127(Heft 103): 196. 1938.

Toledo, Cassio A. P., Souza, Vinicius Castro & Lucas, Eve J., 2020, Nomenclatural and taxonomic updates in Rourea subgen. Rourea sect. Multifoliolatae (Connaraceae), PhytoKeys 169, pp. 137-175 : 137

Rourea chrysomalla Glaz. ex G. Schellenb., in Engler, Pflanzenreich IV. 127(Heft 103): 196. 1938. Fig. 4

Type.

Brazil. Goiás: Chemin du Rio Paranauá á Chico Lobo, dans les campos, 08 Nov 1894 (fr.), A. F. M. Glaziou 20871 (Lectotype: P barcode P02274085!, designated here; isolectotypes: F!-frag., G, K!, MPU!, P!, R!, RB!, S!).

Description.

Subshrubs erect, 0.35-0.65(-0.8) m tall; branchlets densely velutinous, lenticels absent. Leaves 9-17-foliolate, loosely disposed; petiole 0.5-2 cm long, velutinous, with glandular trichomes; rachis 4.5-10 cm long, velutinous, with glandular trichomes; leaflets opposite to subopposite, sessile; blade of the basal pair of leaflets (0.9-)1.2-1.8 × (0.4-)0.8-1.6 cm, orbicular or ovate, others 1.6-3.7 × 0.9-1.6 cm, ovate, narrowly elliptic or narrowly ovate, the apical ones usually elliptic, coriaceous, discolorous, abaxially hirsute to densely hirsute, brownish or greenish, adaxially sparsely hirsute to hirsute, dull, base symmetric or slightly asymmetric, cordate, subcordate or rounded, apex obtuse or rounded, margin flat or slightly revolute, ciliate; midvein abaxially prominent, adaxially flat, secondary veins 4-6 pairs, abaxially prominent or slightly prominent, adaxially flat or slightly prominent, tertiary veins abaxially slightly prominent, adaxially flat or slightly prominent. Inflorescences in axillary or terminal determinate thyrses or panicles; bracts ca. 3 mm long; peduncle 0.7-3 cm long, densely hirsute, with glandular trichomes; rachis 4-9.5 cm long, densely hirsute, with glandular trichomes; lateral branches 0.7-2(-3) cm long, densely hirsute, with glandular trichomes. Flowers loosely disposed; buds 4-7 × 3-4 mm, elliptic or broadly elliptic; pedicel 1-4 mm long, with glandular trichomes, 2 bracteoles located up to the lower half, deciduous or persistent; sepals (5-)6-8 × 1.5-2.5 mm, coriaceous, ovate or narrowly elliptic, outer surface densely velutinous or densely hirsute, with glandular trichomes, inner surface subglabrous, margin ciliate; petals 7-9 × 2-3 mm, narrowly elliptic or narrowly obovate, with sparse glandular trichomes on both surfaces; stamens connate at base by ca. 0.8 mm, shorter series 3-5 mm long, longer series 4-6 mm long, with sparse glandular trichomes; ovary 1-1.3 mm long, densely hirsute, style 2-4 mm long, hirsute, stigma peltate, bilobate. Fruits 1-1.4 × 0.4-0.6 cm, reddish or orangish, outer surface completely velutinous, inner surface subglabrous, apex acuminate, style partially persistent, calyx covering one third or rarely half of the fruit; seeds 0.7-1 × 0.4 cm, arillode yellowish.

Distribution, habitat and phenology.

Rourea chrysomalla is apparently restricted to Distrito Federal (DF), in the midwest region of Brazil (Fig. 5 ). The type specimen label indicates that the material was collected in Goiás state, but it is more likely to have been collected in DF (within the current boundaries of Goiás), which is supported by evidence from several sources. Firstly, the herbarium sheet label of Glaziou’s specimen is from "Chemin du Rio Paranauá, a Chico Lobo"; although the name of this river has been taken as “Parananá”, the penultimate letter more closely resembles a “U”, than an “N”. Secondly, Paranauá stands for Paranoá, a river course from DF, subject of study by Glaziou between 1894 and 1895. This can be confirmed by reports and letters from Glaziou to Missão Cruls ( Cruls’ mission), a large scientific expedition in the Brazilian Central Plateau, promoted to investigate the viability of transferring the capital of Brazil to the Midwest (available at: http://doc.brazilia.jor.br/HistDocs/Relatorios/1896-missao-Cruls-Glaziou-lago-Paranoa.shtml). Glaziou sent detailed reports on aspects of vegetation, soil quality and climate around the Paranoá River and clearly demonstrated his advice to dam its riverbed to set up an artificial lake, which was undertaken only in 1959. This lake is called Lago Paranoá and it was probably built following Glaziou’s reports, suggesting that the botanist indeed collected in areas that are today part of DF. It is also of note that Glaziou’s reports are contemporaneous with his collection of R. chrysomalla . Lastly, according to the description of his itinerary ( Glaziou 1906), the author collected in Goiás from 1894 to 1895 and visited sites around and within what is now DF, indicating that his collections from Goiás also included specimens from DF. This evidence, in addition to the fact that R. chrysomalla is only found in DF, suggests that the type was collected in the present DF. Unfortunately, no information on "Chico Lobo" location was found.

In DF, individuals of R. chrysomalla can be found in the districts of Brasília, Gama, Riacho Fundo, Sobradinho and Taguatinga. This species is a subshrub up to 65(-80) cm tall, occurring in the central Brazilian Cerrado, more specifically in areas of cerrado s. s. or "campo sujo". Rourea chrysomalla is apparently the only species of the genus in which the roots develop a xylopodium. Specimens have been collected with flowers from August to October and in April and with fruits from September to October.

Specimens examined.

Brazil. Distrito Federal: Sobradinho, 10 Apr 1974 (fl.), E. P. Heringer 13232 (UB); Taguatinga, Brasília, 15 Aug 1964 (fl.), E. P. Heringer 9750 (UB, US); Brasília, ca. 15 km E. of Brasília, 30 Oct 1964 (fl.), H. S. Irwin & T. D. Soderstrom 5724 (NY); Disturbed areas in cerrado, ca. 32 km S.W. of Brasília on road to Anápolis, 04 Sep 1964 (fl.), H. S. Irwin & T. D. Soderstrom 6001 (NY, P, UB, US); Riacho Fundo, 15 Oct 1999 (fl.), L. C. Milhomens et al. 03 (UB); Riacho Fundo, (fl.), L. C. Milhomens et al. 04 (UB); A ca. de 25 km sudoeste de Brasília, caminho para Anápolis, 15 Oct 1999 (fl.), L. C. Milhomens & W. R. Anderson 05 (HUEG, UB); Coletada em campo sujo de Cerrado, c/ intensa ação antrópica, 15 Oct 1999 (fl.), L. C. Milhomens 06 (EAC, HUEG, HUFU, HUTO, UB); Riacho Fundo, (st.), L. C. Milhomens et al. 07 (UB); Coletada em campo sujo de Cerrado, c/ intensa ação antrópica, 15 Oct 1999 (fl.), L. C. Milhomens 08 (HUTO, UB); CINDACTA, 05 Oct 1999 (fr.), L. C. Milhomens et al. 09 (UB); CINDACTA, 05 Oct 1999 (fr.), L. C. Milhomens et al. 10 (UB); CINDACTA, -16.01666705, -48.066667, 05 Oct 1999 (fr.), L. C. Milhomens et al. 11 (UB); CINDACTA, 05 Oct 1999 (fr.), L. C. Milhomens et al. 12 (UB); CINDACTA, 05 Oct 1999 (fr.), L. C. Milhomens et al. 13 (UB); CINDACTA, 05 Oct 1999 (fr.), L. C. Milhomens et al. 14 (UB); CINDACTA, 05 Oct 1999 (fr.), L. C. Milhomens et al. 15 (UB); Gama, área pertencente ao CINDACTA, pouco depois do balão de entrada do Gama, 16°01'S, 48°04'W, 05 Oct 1999 (fr.), L. C. Milhomens et al. 16 (EAC, UB); Fazenda Sucupira, áreas nativas a Oeste da sede do Laboratório-BBGA, 15°52'S, 48°00'W, 08 Nov 1996 (fr.), R. V. Nunes et al. 59 (CEN); Riacho Fundo, 25 Sep 1998 (st.), C. E. B. Proença 2063 (UB); Riacho Fundo, (st.), C. E. B. Proença 2064 (UB); Riacho Fundo, (st.), C. E. B. Proença 2065 (UB); Riacho Fundo, (fr.), C. E. B. Proença 2066 (UB); Riacho Fundo, (fr.), C. E. B. Proença 2067 (UB); Samambaia, Parque Boca da Mata do lado esquerdo da polícia, 15°52'S, 48°03'W, 07 Aug 1995 (fl.), J. M. de Rezende 49 (CEN); Cerrado senso stricto, estrada de terra na saída da cidade, 15°59'31"S, 48°02'24"W, 10 Oct 2017 (fl.), C. A. P. Toledo & J. R. L. da Paz 347 (ESA).

Recognition and notes.

Rourea chrysomalla is easily distinguished by the combination of the following characters: branchlets velutinous, leaflets sessile, coriaceous, abaxially densely hirsute, sepals coriaceous, petals with glandular trichomes and fruits with outer surface completely velutinous. This species can be confused with R. prostrata due to their sub-shrubby habit; however, R. chrysomalla is an erect subshrub (vs. prostrate subshrub), has coriaceous leaflets (vs. chartaceous), inflorescences usually terminal (vs. axillary) and fruits measuring 1-1.4 × 0.4-0.6 cm, completely velutinous externally (vs. fruits 0.8-1 × 0.3-0.4 cm, sparsely hirsute especially at apex). Rourea chrysomalla is also similar to R. glazioui , but differs by the subshrubby habit, coriaceous leaflets and petals and stamens with glandular trichomes vs. lianescent habit, chartaceous leaflets and petals and stamens eglandular.

Rourea chrysomalla was described by Glaziou (1906, written as " chrysomala "), but his work is listed in the Suppressed works (Appendix I) of the Code ( Turland et al. 2018), so the name is considered not validly published. Schellenberg (1938) validly published Rourea chrysomalla and gave credits to Glaziou, so the authorship of the name has been attributed to Glaziou ex Schellenberg. The type (Glaziou 20871) indicated by Schellenberg (1938) is from P and, in this herbarium, there are two sheets belonging to this collection. Although each sheet bears the same label from P, only one (barcode P02274085) has an original label with Glaziou’s handwriting indicating location and date, so the two specimens are considered duplicates ( Turland et al. 2018, Art. 8.3); then a lectotype is here proposed.

Figures

Figure 4. Rourea chrysomalla: A flowering branchlet B fruiting branchlet (photo by Jair Faria) C leaves (photo by Jair Faria) D habit.

Figure 5. Geographic distribution of Rourea chrysomalla.