Clusia rubrifructa Bittrich & J.E. Nascim., 2016

Do Nascimento-Jr, José E., Bittrich, Volker & Do Amaral, Maria Do Carmo E., 2016, A new Amazon species of Clusia sect. Brachystemon (Clusiaceae), Phytotaxa 288 (1), pp. 85-90 : 86-89

Clusia rubrifructa Bittrich & J.E. Nascim. , sp. nov.

Type:— BRAZIL. Amazonas: Manaus-Caracaraí Road , km 40, 10 December 1973, W.C. Steward & J.F. Ramos P20099 (bud. fl. ♂), (Holotype INPA!, barcode 44022 , Isotypes: NY!, barcodes 01303609 and 01843676 ). ( Figures 1A–H , 2A & 3 )

Similar to Clusia penduliflora but differing in its leaves with rounded, not acuminate apex; staminate flowers with 40–60 stamens with anthers 1.5–1.8 mm long instead 30–35 stamens with anthers of 2–2.2 mm long in C. penduliflora ; pistillate flowers with 5–10 staminodes. Similar to Clusia spathulifolia but differing in the the lower number of staminodes; foliar apex rounded and glands inconspicuous for the naked eye. Similar to Clusia sipapoana but differing in its staminate flower with a tetra- or pentangular androecium with 40–60 with filaments fused at base instead of 10 stamens completely fused into an umbraculiform structure.

Hemiepiphytic shrub, exudate yellowish; younger branches quadrangular, striate, 2–3.5 mm diam., epidermis peeling in rings, often with aerial roots. Leaves opposite; petioles 6–15 × 1–2.8 mm; leaf blade subcoriaceous to coriaceous, obovate, 7–10(–13) × 3–4.5(–7) cm, scrobiculate on adaxial surface, dull on both leaf surfaces (in sicco), with tiny dark or pale brown dots always visible (with magnification) on the abaxial surface (sometimes also on the adaxial surface), apex obtuse to rounded, never acuminate, base acute to most frequently attenuate, not decurrent on petiole, margin not or only slightly revolute; midvein slightly or not prominent on adaxial surface, and prominent only until near the apex on abaxial surface; secondary veins only slightly conspicuous on adaxial surface, and very conspicuous and prominent on abaxial surface, distant from each other 2–2.7 mm, forming an angle of 30–40° with the midvein in the central region of the leaf; inframarginal vein conspicuous in sicco, distant 1.8–2.5 mm from the margin; exudate canals conspicuous or at least slightly evident on adaxial surface (in sicco), and not visible or inconspicuous on abaxial surface, distant from each other 0.3–2 mm. Inflorescences pendent when mature, staminate ones 4 × 4–6 cm with 9–19 flowers, and pistillate ones 2–4 × 2–5 cm with 1–9 flowers, lax; peduncle flattened, 1–1.5 cm long; inferior bracts semi-orbicular to orbicular, ca. 1.3 × 1.3 mm, carinate abaxially, the others bracts ca. 1 × 1 mm; pedicels 3–5 mm long, tetragonal; bracteoles 2, semi-orbicular, ca. 1 × 1 mm; calicular bracts 2, semi-orbicular, 1.2 × 1.2 mm, fused at base. Floral bud spherical, cream to greenish. Flower at anthesis subcupuliform, 5–7 mm diam.; sepals 7–9, green, semi-orbicular to orbicular, with hyaline margins, the two external ca. 3.5 × 3.5 mm, the two median ca. 4.5 × 4.5 mm, and the 3–5 internal ca. 6 × 7 mm; petals 5, cream, oblong to semi-orbicular, ca. 5 × 3 mm, fleshy and firm, with membranous margins, strongly folded in the floral bud, with the apical part usually fitting into the center of the androecium; staminate flower: pistillode absent, androecium tetra or pentagonal, stamens 40–60, erect, 1.5–1.8 mm long, free portion of filaments 0.5–0.8 × 0.2 mm, fused basally into a column 1.3–1.5 long and 3.5 mm diam., anthers ca. 1 × 0.2 mm, oblong, truncate at the apex, connective brown in sicco, not projecting above the thecae; pistillate flower: staminodes 5–10, 1.7–1.8(–2.3) mm long, antherodes well-developed, 0.7–1 × 0.2–0.3 mm, truncate at the apex, filaments flat, 0.8–1 mm long, broadening abruptly at the base, fused 0.2–0.3 mm with each other at the base; ovary 5-carpels, 5–3.7–4 × 2–3 mm, oblong, stigmas 5, ca. 1.5 × 1.2 mm, papillose, triangular, margins dentate or crenulate, subterminal, not connivent. Fruit green-reddish, submature oblong, subglobose to globose, 2–2.5 × 2 cm, smooth, in compact infructescence, stigmas distant 1–1.5 mm from each other and from the apex of the fruit; petals occasionally persistent, sepals and staminodes persistent.

Etymology: —The specific epithet “rubrifructa ” refers to the external reddish colour of the submature fruits. From Latim: rubru = red, fructus = fruit.

Notes and taxonomic affinities: — Clusia rubrifructa was frequently confused in herbaria with C. sipapoana ( Maguire 1961: 27) Pipoly (1998: 279) , a species belonging to sect. Quapoya , but can be distinguished mainly by its flowers with 7–9 sepals (only 5[6] in C. sipapoana ), the staminate flower with a tetra- or pentangular androecium of 40–60 stamens ( C. sipapoana has 10 stamens fused in a umbrella-like structure typical for the former genus Quapoya ), and pistillate flowers with 5–10 well-developed staminodes, 0.7–1 × 0.2–0.3 mm, truncate at the apex (vs. 5 staminodes of 0.2 × 0.2 mm, with acute to obtuse apex in C. sipapoana ). Moreover, the species is similar to C. penduliflora Engl. , but can be easily distinguished by its leaves with a rounded, not acuminate apex, staminate flowers with 40–60 stamens with anthers 1.5–1.8 mm long, and pistillate flowers with (7)10–15 staminodes of 1.7–1.8(–2.3) mm long (vs. leaves with an acute to obtuse, often acuminate apex, staminate flowers with 30–35 stamens with anthers of 2–2.2 mm long, and pistillate flowers with staminodes of 2–3 mm long in C. penduliflora ). In addition, Clusia rubrifructa can be distinguished from C. spathulifolia , also of sect. Brachystemon , by the rounded leaf apex and glands inconspicuous for the naked eye on abaxial surface of leaves ( Figure 2 ). Table 1 shows other differences between species of sect. Brachystemon .

Distribution: —Primary or disturbed Amazon low land forests of Brazil, Colombia and Peru ( Figure 3 ).

Ecology and conservation: —Despite its wide geographic distribution, Clusia rubrifructa is a rarely collected species. Therefore, we categorize the new species as data deficient (DD) using the criteria of IUCN (2001). Up to now, there is no information about its ecology, besides the basic data about its habitat in the Amazonian lowland forest.

Additional specimens examined (Paratypes): — BRAZIL. Amazonas: Manaus-Porto Velho Highway , km 253, 19 March 1974, G.T. Prance et al. 20732 (fr.) (INPA!, NY!) ; Fonte boa, Paraná do Mamupina, varadouro Ponta da Ariramba , 2°42’S, 65°59’W, 03 November 1986, C.A. Cid et al. 8382 (bud. fl.) (NY!) . COLOMBIA. Amazonas: Araracuara, Villazul , Río caquetá, left margin in front to Sumaeta Island , 0°34’S, 72°08’W, 31 October 1989, C. Londoño et al. 974 (bud. fl.) (NY!) ; 0°39’S, 72°8’W, 24 June 1990, C. Londoño et al. 877 (bud. fl.) (COAH!); Cuenca del medio Caquetá, region de Araracuara, Comunidad de Peña Roja , 0°41’S, 72°07’W, 09 June 1998, A.P. Rosselli & A. Rodríguez 142 (fr.) (COAH!) ; 0°39’31”S, 72°04’38”W, 14 October 1997, A.C. Londoño & P. Tucano 2409-A (fl. ♂) (COAH!). PERU. Dep. Loreto: Prov. Loreto, Carretera Nauta-Iquitos , km 6, 04°29’S, 73°35’W, 150 m elev., 6 June 1983, R. Vásquez 4173 (fl. ♂) (USM!) ; Prov. Maynas, Mishana, Río Nanay , half-way between Iquitos and Santa Maria de Nanay, trail to Campamento 1, transect 4, ca. 180 m elev., 30 May 1978, A. Gentry, C. Díaz & J. Ruíz C. 22416 (fl. ♀, fr.) (NY!, USM!) ; Varillal, carreterra a Nauta , 3°45’S, 73°21’W, 130 m elev., 8 January 1981, R. Vásquez & N. Jaramillo 1212 (sterile) (NY!) ; Sargento Lores, Esperanza ( Rio Tahuayo ), 04°10’S, 73°15’W, 120 m elev., 12 December 1989, R. Vásquez & N. Jaramillo 13198 (fl. ♂) (USM!) ; 13 December 1989, R. Vásquez & N. Jaramillo 13198 (fl. ♀) (USM!); Prov. Requena, Pari, Jenaro Herrera , 4°50’S, 73°45’W, 170 m elev., 10 December 1980, R. Vásquez & N. Jaramillo 1043 (bud. fl. ♂) (NY!, USM!) .

Figures

FIGURE 1. Clusia rubrifructa Bittrich & Nascimento-Jr. A. Branch with floral buds. B. Detail of abaxial surface showing brown glands. C. Staminate flower at the beginning of anthesis. D. Androecium. E. Stamen in ventral, lateral and dorsal views (left to right). F. Pistillate flower at the beginning of anthesis. G. Gynoecium and staminodes (note the basal fusion of staminodes). H. Fruit submature.

FIGURE 2. Abaxial surface and foliar apex of three species of section Brachystemon: A. Clusia penduliflora, Spruce 2792. B. Clusia rubrifructa, Gentry 22416. C. Clusia spathulifolia, Spruce 2782 (note the high density of brown glands visible for the naked eye). Scale bar = 5 mm.

FIGURE 3. Distribution map of Clusia rubrifructa.