Sipaneopsis duckei Delprete, 2018

Delprete, Piero G., 2018, Two new species of the tribe Sipaneeae (Rubiaceae) from white-sand areas of Brazilian and Colombian Amazon, Phytotaxa 382 (1), pp. 125-135 : 130-132

Sipaneopsis duckei Delprete , sp. nov.

Type:— BRAZIL. Pará: Mun. Oriximiná, Campos do Ariramba, campina inundavel do Rio Jaramacarú , solo arenito, 90 m, 8 June 1980 (fl, imm fr), G. Martinelli 6869 ( RB 202995 ) (holotype, MG [Acc. No. 92530]; isotypes, INPA [Acc. No. 101497], NY [2 sheets, barcodes 02693457 and 01552866], RB n.v., UB). ( Fig. 2 ) .

Sipaneopsis duckei Delprete is similar to S. maguirei Steyermark (1967: 287) in several aspects, e.g., stipules entire (not lobed), inflorescences congested-cymose, style slightly shorter or about the same length of the corolla tube, and seeds 6–8 per locule. The previous differs from the latter in having stout, erect stems (vs. thin, reclining, decumbent or ascending in S. maguirei ); stipules (2.5 −)3–6.5 × 1.5–3.5 mm (vs. 1.5–3.5 × 1–2 mm); inflorescences (12–)19–58- flowered (vs. 2–8-flowered); corolla 17.5–22 mm long and tube 12–16 mm long when fully elongated (vs. corolla 21–30 mm and tube 15–22 mm long when fully elongated); and fruits 4–5 × 4–5 mm (vs. 3.5–4 × 3.5–4 mm).

Subshrub to shrub 0.3–1.6 m tall, erect or ascending (rarely decumbent), few- to many-branched; stems stout, woody; young branches sparsely hispid-strigose or appressed to spreading strigose (hairs 0.3–0.6 mm long). Stipules free at base or narrowly connate to the petioles, entire (not lobed) or rarely bilobed at older nodes, base broadly triangular and distal portion linear, or narrowly triangular to narrowly oblong-triangular, (2.5 −)3–6.5 × 1.5–3.5 mm, lobes (when present) narrowly triangular to linear (sometimes with a terminal colleter), hispid-strigose to spreading-strigose outside, sericeous and with a raw of colleters at base (populations in Serra Aracá) or glabrous and with a basal portion of sericeous hairs and a few colleters (populations of Campos do Ariramba) inside, persistent. Leaves subsessile to petiolate; petioles to 5.5 mm long, hispid-strigose or appressed to spreading-strigose (hairs 0.3–0.5 mm long); blades ovate, narrowly ovate, elliptic-lanceolate, narrowly elliptic to narrowly oblong-elliptic, (2.5 −)3.5–8.5 × (0.6–) 1–3.5 cm, round, obtuse to attenuate at base, acute at apex, subcoriaceous, margins planar or narrowly revolute, dark green above and pale green below when fresh, drying dark brown above and pale brown below, lamina glabrous or and midrib appressed strigose above, lamina glabrous or sparsely strigose and primary and secondary veins sparsely to densely appressed strigose below; secondary veins 6–10 each side of midrib, strongly depressed above, prominent below. Inflorescence congested-cymose (branched portion reduced), dichotomously branched, (12–)19–58-flowered, 2.2–10 cm long (including peduncle and flowers), 1–3 cm broad (expanding after anthesis), sometimes frondose, i.e. subtended by leaf-like bracts (i.e., pherophylls), these (when present) narrowly ovate to lanceolate, 1–3.5 × 0.2–1 cm, acute at apex, lamina sparsely strigose and primary and secondary veins densely appressed-strigose below, margins strigose-ciliate; peduncle 0.7–7.5 cm long, densely strigose; bracts subtending secondary branches lanceolate, narrowly elliptic to narrowly oblong-elliptic, (1–)2–4.5 × (0.3–) 0.5–1.5 mm, attenuate at base, acute at apex; terminal branchlets scorpiod, 0.5–15 mm long (elongating after anthesis), densely strigose. Flowers sessile to short-pedicellate, secundiflorous, with one bracteole opposing each flower and one subtending each flower (the one subtending the flower smaller than the one opposing the same flower), these sessile, lanceolate to narrowly lanceolate, decreasing in size towards branch tip, 1.5–4.5 × 0.5–1.1, acute at apex, sparsely strigose, margins ciliate-strigose; central flower sessile to sub-pedicellate, pedicel (when present) to 1.3 mm long, lateral flowers sessile. Hypanthium globose, broadly-obovoid to obovoidturbinate, 1–1.5 × 0.8–1.5 mm, densely to sparsely strigose. Calyx tube extremely reduced or absent; lobes 5, equal or subequal, ovate, lanceolate to narrowly lanceolate, 1.5–2.5 × 0.7– 0.1 mm, acute at apex, strigose outside, margins strigose-ciliate, glabrous inside, with 1 or 2 colleters at base of each sinus. Corolla salverform, pink, 17.5–22 mm long when fully elongated; tube cylindrical, slightly expanded at mouth, 12–16 mm long when fully elongated, 0.5–0.7 mm wide at base, 1.6–2 mm wide at mouth, sparsely appressed-strigose and distally more densely so outside, glabrous at basal 3–3.5 mm and sparsely puberulous at upper portion inside; lobes left-contorted, broadly obovate (almost round), obovate to elliptic, 4.5–7 × 2–4 mm when fully expanded (perpendicular to the tube), round, obtuse to acute at apex, sparsely appressed strigose outside, glabrous and papillose inside. Stamens included (anthers tips ca. 1–1.3 mm below corolla mouth) or about the same length of the tube, inserted 2–3 mm below corolla mouth; anthers subsessile, oblong-elliptic, 1.5–2.1 mm long, acute at both ends. Style included (slightly shorter then or about the same length of the tube), 12–14 mm long when fully elongated, glabrous; style branches narrowly lanceolate, ca. 1 mm long. Infructescence a compound dichasium, 6.5–8.5 cm long, terminal branches scorpiod, 1.5–3 cm long. Fruit globose, 4–5 × 4–5 mm, appressed strigose, crowned by the permanent calyx lobes (larger then in flowers, 3–4.5 mm long), falling off as dispersal unit. Seeds 6–8 per locule, irregularly ellipsoid to subglobose, 0.9–1.1 × 0.8–1 mm, rugose-foveolate, testa pale brown.

Distribution and ecology:—A species occurring in two populations in Campos do Ariramba, state of Pará, and in Serra do Aracá (tepui formation), state of Amazonas, in the northernmost region of Amazonian Brazil; endemic to white-sand savannas with sparse trees and shrubs, locally called campinarana, often seasonally inundated; most collections were made at 80–100 m altitude, and a few collections were made at 1200–1220 m altitude on the plateau of Serra Aracá.

Phenology:—Specimens with flowers in anthesis were collected in January, February, May, July, October and December. Three gatherings with flowers and fruits were collected in January, June and July.

Suggested conservation status:— Sipaneopsis duckei is known from numerous collections from two distant areas of white-sand savannas, Campos do Ariramba, state of Pará, and Serra do Aracá (tepui formation), state of Amazonas, in the northernmost region of Amazonian Brazil. The extent of occurrence (EOO) is therefore not calculable. The species occurs in remote areas, without imminent threat. It is therefore considered Not Threatened [NT] according to IUCN criteria ( IUCN 2012, 2016).

Etymology:—The specific epithet of this taxon is dedicated to Adolpho Ducke (1876–1959), famous botanist and entomologist that collected for nearly 50 years in the Amazon basin of Brazil, often in remote places still botanically little-known as of today. This epithet is dedicated to him because he was the first botanist to make plant collections in Campos do Ariramba, northern portion of the state of Pará, Brazil, where he also made the first collection of this species. He described his difficult expedition to reach this locality, which took place during 7–27 December 1906, going upstream the Rio Trombetas, and then its affluent Rio Jaramacarú, followed by several days cutting a trail through difficult terrain, in an article published the following year ( Ducke 1907). He collected Sipaneopsis duckei Delprete two days before reaching the open fields of Campos do Ariramba, in an area of campinarana, on 20 December 1906 (A. Ducke s.n. (MG 8020), MG, unicate). The gathering Martinelli 6869 (RB 202995), collected in the same locality 74 years later, is designated as the type of this taxon because it has duplicates of flowering specimens deposited in several herbaria (INPA, MG, NY [2 sheets], RB, UB).

Notes:— Sipaneopsis duckei is also similar to S. rupicola (Spruce ex K. Schumann 1889: 222) Steyermark (1967: 285 , fig. 29g –m) by being a subshrub to shrub with stout, strigose to strigulose branches, subcoriaceous leaves, and inflorescences 19–58-flowered. The former differs from the later by having stipules entire or rarely bilobed at older nodes (lobes narrowly triangular to linear, sometimes with a terminal colleter), base broadly triangular and distal portion linear, or narrowly triangular to narrowly oblong-triangular, (2.5 −) 3–6.5 mm long, hispid-strigose to spreading-strigose outside; whereas, in S. rupicola the stipules are triangular, 4–5 mm long, entire and caudate, or triangular at base and with 2 or 3 acute lobes, or the base reduced to a line with 6 or 7 linear lobes, densely strigulose outside. In Sipaneopsis duckei the corollas are 17.5–22 mm long when fully expanded, tubes are 12–16 mm long when fully expanded, sparsely appressed-strigose and distally more densely so outside, glabrous at basal 3–3.5 mm and sparsely puberulous at upper portion inside; lobes are broadly obovate (almost round), obovate to elliptic, 4.5–7 × 2–4 mm when fully expanded (perpendicular to the tube), round, obtuse to acute at apex, appressed strigose outside, papillose inside. In S. rupicola the corollas are 16–16.2 mm long when fully expanded; tubes are 11.5 mm long when fully expanded, sericeous-strigose (densely so near the mouth) outside, glabrous at basal 3.5–4 mm and puberulent above and papillose near the mouth inside; the lobes are left-contorted or irregularly imbricate (1 or 2 external), subequal, oblong-obovate, 4.5–4.7 × 2.2–2.5 mm when fully expanded, obtuse to round at apex, sparsely strigulose outside, glabrous inside.

Additional specimens examined (paratypes): BRAZIL. Amazonas : Mun. Barcelos, Parque Estadual da Serra do Aracá, vegetação arbustiva com afloramentos e alagados, com pequena mata na margem de igarapé, 0°55’24”N, 63°25’58”W, 1220 m, 1 September 2011 (fl), R. C. Forzza, G. Martinelli, M. A. Moraes, D. P. Costa & R. Azoury 6632 ( INPA) ; Rio Aracá , afluente do Rio Negro, campinarana, solo arenoso, 24 October 1952 (fl), R. L. Fróes & G. Addison 29039 ( IAN) ; Mun. Barcelos , campina, palmar Barcella odora y sabana sobre arena blanca, ubicadas en la ribera izquierda del Rio Aracá medio, ca. 16 km al SE (el línea recta) de la boca del Rio Januarí, ca. 00°25’N, 63°23’W, 100 m, July 1985 (fl), O. Huber, G. T. Prance, J. M. Pires, I. Cordeiro, J. Guedes, C. D. Mota, E. L. S. da Silva & J. A. C. da Silva 10782 ( INPA, NY) ; base of Serra do Aracá , 0 − 3 km S of Central Massif, 3 km E of Rio Jauari, white-sand savanna, 0°49’N, 63°19’W, 6 February 1984 (fl), G. T. Prance, M. G. da Silva, L. A. Cisneros & C.D. A. da Mota 28853 ( INPA, MG, NY, UB, US) ; plateau of northern massif of Serra Aracá , 0°51 − 57’ N, 63°21 − 22’ W, 1200 m, 11 February 1984 (fl), G. T. Prance, I. L. Amaral, J. J. Pipoly, A. S. Tavares, M. G. da Silva, C.D. A. da Mota & A. Cress 28939 ( INPA, MG, NY, UB, US) ; 3 km S of central massif of Serra Aracá , 0°49’N, 63°17’W [specimen label reports “ 65°17’W ” which is a typographical error], 100 m, savanna on sand, dominated by Lagenocarpus , 18 July 1985 (fl), G. T. Prance, E. L. S. da Silva, I. Cordeiro, C. D. Mota & O. Huber 29680 ( INPA, MG, NY, US) ; margin of Rio Aracá , near Serrinha, open savanna on sand, sedge dominated, 0°25’N, 63°23’W, 80 m, 25 July 1985 (fl, fr), G. T. Prance, C. D. Mota & E. L. S. da Silva, 29798 ( INPA, MG, NY, US) ; N margin of Rio Aracá , just above Igarapé Sauadaua, savanna on white sand, 0°13’N, 63°08’W, 80 m, 26 July 1985 (fl), G. T. Prance, O. Huber & J. A. C. da Silva 29798 ( NY) ; 3 km S da parte central da Serra Aracá , no caminho entre a pista de baixo e a encostas, e a 8 km E do Rio Jauari, solo silicoso ao redor do campamento, campina lenhoso-graminóide [campina-rana], 0°49’N, 63°19’W, 13 March 1984 (fl, imm fr), W. A. Rodrigues, I. L. Amaral, M. G. Silva, Carlitos & M. Miranda 10653 [Aracá Inventory IL 2-6] ( INPA, NY) ; 3 km S da parte central da Serra Aracá , 8 km E do Rio Jauari, solo silicoso ao redor do campamento, campina lenhoso-graminóide [campina-rana], 0°49’N, 63°19’W, 13 March 1984 (fl, imm fr), W. A. Rodrigues, I. L. Amaral, M. G. Silva, Carlitos & M. Miranda 10662 [Aracá Inventory IL 7-18] ( INPA, NY) ; parte baixa ou pé da Serra Aracá, terreno arenoso ou catinga, 21 February 1977 (fl), N. A. Rosa & M. R. Cordeiro 1562 ( MG, NY [2 sheets]) ; arredores do rio da Serra Aracá, 28 January 1978 (fl, fr), N. A. Rosa & S. B. Lira 2268 ( MG, NY, UB). Pará: Campo do Jamaracarú , perto do barracão, Região do Ariramba, 26 May 1957 (fl), G. A. Black, W. Egler, P. Cavalcante & A. Silva 57-19606 ( IAN) ; Alto Ariramba , campinarana, 20 December 1906 (fl), A. Ducke s.n. ( MG 8020 ) ( MG; the first collection of this species) ; Mun. Óbidos , Jaramacarú, 27 May 1957 (fl), W. A. Egler 273 ( MG) ; Mun. Óbidos , Campos do Ariramba , campos near Igarapé Mutum and Rio Ariramba, white-sand soil, 4 December 1987 (fl), C. Farney & E. F. Batista 2057 ( NY, US) ; Mun. Óbidos , 91 km de Oriximiná , Campos de Ariramba , entre Rio Jaramacaru e Igarapé Mutum, campina aberta, solo areno-pedregoso, ca. 1°10’S, 55°35’W, 4 December 1987 (fl), C. A. C. Ferreira 9769 ( INPA) ; Mun. Oriximiná , Campos do Ariramba , campinas da margem do Rio Jaramacarú , afloramento arenítico, 80 m, 8 June 1980 (fl, imm fr), G. Martinelli, C. Davidson & C.D. A. Mota 6929 ( INPA) .

Figures

FIGURE 2. Sipaneopsis duckei. A. Branch with two frondose inflorescences and one infructescence (note last fruit on the infructescence). B. Stipule. C. Detail of an inflorescence. D. Flower at early stage of anthesis. E. Flower at intermediate stage of anthesis. F. Flower at final stage of anthesis, with corolla lobes reflexed, and receptive stigmas. G. Indehiscent fruit, fallen off as dispersal unit. A–B: drawn from Egler 273 (MG); C, G: drawn from Rosa & Lira 2268 (MG); D–F: drawn from Prance et al. 28853 (US). Illustration by Piero Delprete.