Clusia nitida Bittrich & F. N. Cabral, 2013

Bittrich, Volker, Cabral, Fernanda Nunes & Hopkins, Michael John Gilbert, 2013, Clusia nitida, a new species of Clusia (Clusiaceae) from the Brazilian Amazon, Phytotaxa 100 (1), pp. 36-40 : 36-40

Clusia nitida Bittrich & F. N. Cabral , sp. nov. (sect. Phloianthera) ( Fig. 1 & Fig. 2 )

Diagnosis: Similar to Clusia microstemon , but dry leaves are darker coloured and generally have a shiny surface, the latex channels are denser on the adaxial surface, the midrib is conspicuous as far as to the apex, the petal colour is different and anthers are absent on the lateral part of the disk-like androecium. The new species is also similar to Clusia myriandra from which it differs by the leaf shape, the visibility of the latex channels on the leaves, the shorter peduncle and basal internodes in the inflorescence, the size of the fruits and the lesser number of seeds.

Type:— BRAZIL. Roraima: Caracaraí, Parque Nacional do Viruá , White-sand vegetation, 1º24’50.7”N, 60º59’16.5”W, 59 m, 15 October 2010, F.N. Cabral & V . S. Santos 298 (holotype INPA!) .

Trees, small trees or shrubs up to 6 m tall; sometimes with prop roots. Plants dioecious, latex white or cream; young branches cylindrical or more frequently subangular, surface not rugulose, but finely sulcate or with tiny longitudinal foldings, linear colleters present in the petiole axils, deciduous with the leaves. Petiole 4.0–16.0(– 17.0) mm long, margin flat to revolute. Leaf blade coriaceous, discolorous, adaxial surface dark brown and shiny in sicco, oblong-elliptic, 40–85(–108) mm long and (18–)21–49(–53) mm wide, apex rounded, base attenuate, margin revolute; midrib prominent on the adaxial surface and conspicuous as far as the apex, secondary veins prominent on both surfaces, with (9–)12–26(–29) pairs, 1.5–4.0 mm distant from each other and at an angle of 35º–40º with the midrib, basal veins inconspicuous; latex canals concolorous on the adaxial surface or slightly darker than the blade, immersed, 0.3–0.7 mm distant from each other, flat to protruding on the abaxial surface, 0.8–1.0 mm distant from each other, forming an angle of about 25º with the midrib. Inflorescence cymose, compact, 3–9-flowered (staminate plants) or 3–7-flowered (pistillate plants), bracts and bracteoles united at the base, hemiorbicular, ca. 2 mm long, pedicels very short, ca. 2 mm long, quadrangular. Epicalyx bracts 2 (+2), united at base, sepals 4 (2+2), rarely 5 or 6 (2+3, 3+3), ± suborbicular, ca. 4–8 mm long and 4–8 mm wide. Petals 5–8, 6–13 x 6–12 mm, dark bordeaux or blood-red. Staminate flower with the androecium forming a thick, circular, flat disk, ca. 3–6 mm wide, composed of about 300 densely compact stamens, the upper surface covered by a mixture of resin and pollen during anthesis, filaments 2.3–3.0 mm long, lateral region of the disk without anthers, anther dehiscence by apical or transverse slits. Pistillate flower with 3 or 4 series of staminodes around the base of the ovary, secreting resin at the apex; staminodes linear, 1.3–2.0 mm long, truncated at the apex, without sterile anthers; stigmas 4 or 5, apical, yellowish, obtusely triangular, flat, 2.5 mm long; ovary yellow, ovules 1 or 2(–3) per locule. Immature fruit oval to hemispherical, 15–22 x 13–19 mm, usually finely longitudinally striate with latex canals; sepals, staminodes and stigmas persistent, valve endocarp not conspicuously hardened. Seeds 1 or 2(–3) per locule, 5.0–9.0 x 3.5–5.0 mm, green, aril orange.

Comparison: —The most similar species is C. microstemon Planchon & Triana (1860: 331) , which sometimes occurs sympatrically, and with which C. nitida has been confused. It has a wide distribution in the Amazon. The main difference between the species is the male androecium, which in C. microstemon has anthers at the lateral side of the androecial disk, whereas C. nitida has anthers only on its top. Other differences include the darker colour and the glossy appearance of the leaf surfaces in sicco in C. nitida ; the androecium size, which is larger in C. microstemon ; the flower colour, in C. microstemon the petals are reddish to pinkish-purple in the centre and white-pink on the edge and the calyx is white-pink, while in C. nitida the petals are dark bordeaux or blood-red and the calyx is green; C. microstemon has 4 or 5 ovules per locule, whereas C. nitida has only 1 or 2(–3) ovules per locule; the fruits of C. microstemon are slightly ovoid and in C. nitida they are generally cylindrical, and finally, C. microstemon has a lower density of latex channels on the leaves than in C. nitida and the midrib becomes invisible in the apical part of the leaves.

Another similar species is C. myriandra ( Bentham 1843: 368) Planchon & Triana (1860: 332) from the Guianas, which has a very similar androecium. However, C. myriandra has elongated and oblanceolate leaves, unlike C. nitida , which has shorter and more rounded broader leaves; the latex channels of the leaves, which are easily visible in C. nitida , are invisible in the strongly coriaceous leaves of C. myriandra ; the peduncle and the basal internodes in the inflorescence are much longer in C. myriandra , positioning the inflorescence above the foliage and C. myriandra has more elongated and larger fruits than C. nitida with 10 or more seeds per locule, while the fruit locules of C. nitida have only 1 or 2(–3).

Etymology: —Latin nitidus = shiny, because the dried leaves generally have a conspicuously shiny surface, different from those of C. microstemon , the leaf surface of which is typically dull.

Distribution and habitat: —In Brazil, Clusia nitida is known from the North Region, in the states of Amazonas and Roraima. Apparently, it has not yet been collected outside of Brazil. It mainly occurs in whitesand vegetation and at river margins in Amazonian lowlands.

Additional specimens examined (paratypes): — BRAZIL. Amazonas: 2 km from Rio Cuieiras at km 2 below mouth of Rio Branquinho , 02°45' S, 60°47' W, 14 September 1973, G. T. Prance et al. 17912 (GH!, INPA!, K!, MO!, NY!, S!, U!, US) ; Rio Cuieiras just below mouth of Rio Branquinho , 2°45' S, 60°27' W, 25 September 1971, G. T. Prance et al. 14848 (MO, R!) ; Rio Cuieiras , 2 July 1975, A.B. Anderson 140 ( INPA!, MG!, UEC!) ; s.loc., 27 April 1975, A.B. Anderson 177 ( INPA!, NY!, UEC!) ; Rio Cuieiras , 9 October 1988, S. Mori & C. Gracie 19270 ( INPA!) ; Manaus–Caracaraí km 130, 26 September 1974, G. T. Prance & F. Ehrendorfer 22749 ( INPA!) , 26 September 1974, G. T. Prance & F. Ehrendorfer 22750 ( INPA!) ; Manaus– Caracaraí km 131, 1°59' S, 60°16' W, 1 December 1974, A. Gentry 12961 (GH!, INPA!, MG!, MO!, NY!) ; km 140, 27 September 1973, C.C. Berg et al. P18180 ( INPA!) ; km 125, 22 September 1977, W.A. Rodrigues & M.F. Silva 9765 ( INPA!) ; km 115, 28 August 1977, W.A. Rodrigues 9717 ( INPA!) ; Barcelos, margin of Rio Aracá next to mouth of Rio Jauari , 00°30' N, 63°30' W, 2 July 1985, I. Cordeiro 118 ( INPA!, NY, UEC!) ; 3 km S Central Massif of Serra Aracá , 00°49' N, 63°17' W, 18 July 1985, G. T. Prance et al. 29676 ( INPA!, NY, UEC!) ; margin of Rio Aracá near Serrinha , 00°25' N, 63°23' W, 25 July 1985, G. T. Prance et al. 29767 ( INPA!, NY, UEC!) ; foothills of Central Massif of Serra Aracá , 00°49' N, 63°20' W, 12 July 1985, G. T. Prance et al. 29502 ( INPA!, NY, UEC!) ; 5 km S Central Massif of Serra Aracá , 00°49' N, 63º17' W, 20 July 1985, G. T. Prance et al. 29699 (NY, UEC!) . Roraima: 7 km south of Equator , BR 174 , 00°05' S, 60°40' W, 14 June 1985, I. Cordeiro et al. 30 ( INPA!, NY!) ; Manaus–Caracaraí km 522–524, 01°18' S, 60°35' W, 25 August 1987, C.A.C. Ferreira 9147 ( INPA!, NY, UEC!) ; Parque Nacional do Viruá , 1º16' N, 60º58´W, 25 November 2009, F.N. Cabral et al. 5 ( INPA!, UEC!) ; Parque Nacional do Viruá , 1º29' N, 61º02´W, 26 November 2009, F.N. Cabral et al. 23 ( INPA!, UEC!) ; Parque Nacional do Viruá , 1º29' N, 61º02´W, 26 November 2009, F.N. Cabral et al. 26 ( INPA!, UEC!) ; Parque Nacional do Viruá , 1º28' N, 60º57´W, 29 November 2009, F.N. Cabral et al. 49 ( INPA!, UEC!) ; Parque Nacional do Viruá , 1º26' N, 61º01´W, 2 December 2009, F.N. Cabral et al. 82 ( INPA!, UEC!) ; Parque Nacional do Viruá , 1º23' N, 60º59´W, 5 December 2009, F.N. Cabral et al. 123 ( INPA!, UEC!) ; Parque Nacional do Viruá , 1º16' N, 60º58´W, 29 January 2010, F.N. Cabral et al. 197 ( INPA!, UEC!) ; Parque Nacional do Viruá , 1º14' N, 60º58´W, 5 March 2010, N. Dávila et al. 6129 ( INPA!) .

Probably also R.L. Fróes 25319, Rio Urubú, Peixe Boi, 02°05' S, 60°05' W, 20 September 1949 (IAN!) belongs to Clusia nitida , but the androecium of this specimen is hemispherically bulged similar as in Clusia hilariana Schlechtendal (1833: 181) .

Figures

FIGURE 1. A. Disposition of leaves and inflorescences, F.N. Cabral 49 (Photo F.N. Cabral). B. Pistillate flower, F.N. Cabral 123 (Photo F.N. Cabral). C. Staminate flower, F.N.Cabral5 (Photo F.N. Cabral). D. Immature fruit, F.N. Cabral 197 (Photo F.N. Cabral). E. Mature fruit, N. Dávila 6129 (Photo N. Dávila).

FIGURE 2. A. Disposition of leaves and inflorescences. B. Leaf venation and latex channels. C. Pistillate flower. D. Detail of pistil and staminodes. E. Longitudinal section of ovary. F. Staminate flower. G. Detail of androecium. H. Disposition of leaves and fruit. I. Immature fruit. J. Seed. A, F–G from F.N. Cabral 82; B–E & H–J from F.N. Cabral 23. Drawing by Klei Souza.