Monoecious or Dioecious Shrubs or Trees up to 45 m high; branches :±: lenticellate; branchlets pinnatiform, usually subtended by smaller leaves (but generally not reduced to cataphylls), axes terete, glabrous or pubescent, not (or scarcely) lenticellate, with distichous leaves. Leaf Blades glabrous or pubescent, elliptic or ovate to lanceolate, mostly acute or acuminate, pinnately veined, brochidodromous; midrib incised adaxially; prominently raised abaxially; lateral veins arching, :±: prominulous adaxially, distinctly prominulous abaxially; adaxial surface usually smooth and shiny; abaxial surface paler, often minutely puncticulate; petiole terete, often rugulose; stipules lanceolate, persistent or deciduous. Inflorescences glomerulate, axillary, unisexual (rarely bisexual); glomerules sessile or pedunculate; bracts indurate, persistent. Staminate flowers pedicellate; sepals 6 (rarely 5), usually in two whorls; disk-segments discrete or more often coalesced into a 6-lobed disk; stamens 3, filaments free (in P. skutchii), coherent or connate; anthers dehiscing horizontally to obliquely; pollen grains spheroidal, lacking distinct ectocolpi, exine heterogeneously pilate. Pistillate flowers pedicellate; sepals 6, discrete; disk patelliform to cupular; ovary 3- to 6-locular (2-locular in P. awaensis); styles free or connate, bifid or unlobed. Fruits indehiscent, exocarp fleshy or coriaceous; seeds with sarcoexotesta, exotegmen hard and smooth.

Sect. Hylaeanthus includes seven species of mainly South American distribution (with one species in Costa Rica); an additional Venezuelan species, Phyllanthus bernardii Jabl., may also belong to the section. Within subgenus Conami (Aubl.) G. L. Webster, sect. Hylaeanthus is distinguished by unramified branchlets and indehiscent fruits with sarcotestal seeds. The distinctive pilate exine ornamentation of the pollen grains (Webster and Carpenter, 2002, Figs. 9, 10) separates the species of sect. Hylaeanthus from most other woody taxa of Phyllanthus. Pollen grains of some taxa of sect. Nothoclema are similar, but in that section the fruits are dehiscent and the branchlets mostly bipinnatiform. Vegetatively, some of the species of sect. Hylaeanthus are similar to Amazonian species of the neotropical sect. Elutanthos (subg. Xylophylla). However, in that section the pollen grain exine is clypeate (synrugoidorate) and the fruits are dehiscent.

As noted by Meewis and Punt (1983), pilate pollen exines occur in other species of Phyllanthus, notably in the West African P. dinklagei Pax, which Brunel & Roux (1977) have referred to sect. Brazzeani in subg. Conami. Based on published descriptions, sect. Brazzeani morphologically resembles sect. Hylaeanthus in some respects, although it differs in its 5-merous perianth, discrete staminate disk-segments, and free stamens of unequal lengths. Because of these floral differences, it appears likely that the similarities in pollen exine sculpturing between species of sects. Hylaeanthus and Brazzeani represent an instance of convergence rather than a close phylogenetic relationship, as suggested by Punt (1986).

The staminate flowers are so similar in most species of sect. Hylaeanthus that they offer few useful diagnostic characters; staminate specimens often can only be determined with certainty by using vegetative characteristics. The pistillate flowers, however, show considerable variation in stylar structure and number of carpels, although this morphological diversity can sometimes be erratic and difficult to interpret. The number of locules in the ovary, although often 3 or 4, may sometimes be 5 or 6; only P. callejasii G. L. Webster and P. awaensis G. L. Webster seem to be strictly 3-locular and 2-locular respectively (and that may reflect inadequate sampling). Unfortunately, the number of ovary locules is quite variable within species or even individuals, so that carpel number is sometimes oflimited utility as a diagnostic character. Perhaps the most important diagnostic floral feature is that of the configuration of the styles, which are erect and subentire in P. awaensis and madeirensis; erect and bifid in P. puntii and P. skutchii; but bifid and more or less spreading in the other species. The indehiscent fruits and fleshy seeds are rather similar in all species, although there are some differences in size. The sarcotesta of the seed is usually elongated considerably beyond the hard exotegmen. Because of the variability in size of the fleshy tissue, seed measurements have been limited to the exotegmen.

A characteristic feature of the inflorescence in sect. Hylaeanthus is its contraction into glomerules with scarious bracts that often become indurated in pistillate specimens. These glomerules terminate a stout peduncle that varies in length in different species. In the widespread Phyllanthus attenuatus ssp. attenuatus, the peduncle is usually contracted (1 mm or less in length) or even totally suppressed, but in P. attenuatus ssp. incarum and most other species, the peduncles may become as much as 4 mm long or more. However, the rather erratic variation in peduncle length is an obstacle to using the character for separating taxa.

The sectional epithet Hylaeanthus was chosen to indicate the prevalent distribution of the species in lowland Amazonian rain forest; only one species, Phyllanthus skutchii Standl., occurs in Mesoamerica (Costa Rica). However, two species, P. awaensis and P. callejasii, grow in montane forests mainly above 1,000 m. The distribution map of the taxa (Fig. 1) has been prepared from a data base (Microsoft Access) that includes geographical coordinates of more than 95% of the specimens cited. Many of the determinations of elevation have been obtained from the Ornithological Gazetteer of Brazil by Paynter and Traylor (1991, and earlier issues for other South American countries).

Monoecious or Dioecious Trees, glabrous, 8–45 m high, trunk c. 0.2–1 m in diameter; bark fissured; branchlets mostly 15–30 cm long, 0.9–1.6 mm in diameter, with 10–20 leaves. Leaf blades ellipticlanceolate, acuminate (acumen c. 1 cm long), 6–9 × 2.5–3.5 cm, with 8–10 lateral veins; petiole mostly 3–5 ( 6) mm long; stipules lanceolate-acuminate, 1–1.5 mm long, persistent. Flowers in axillary usually unisexual glomerules, the staminate sessile at proximal axils with 20–30 flowers; the pistillate short-pedunculate (1–1.5 mm), with (1-) 5–10 flowers, at distal axils. Staminate pedicel 2.5–5 mm long; sepals 6, broadly·obovate to elliptic, outer sepals 1.4–1. 7 mm × c. 1 mm, inner sepals 1.2–1.4 × 1.1–1.2 mm; disk cupular, ±12-lobed, c. 1 mm in diameter; stamens 3, filaments free, 0.3–0.4 mm long; anthers truncate-emarginate, broader than long, c. 0.25 × 0.30 mm. Pistillate pedicel (3-) 4–6 mm long; sepals 1.5–2.5 × 1.2–1.7 mm; disk crenulate, c. 0.3 × 0.8–1 mm; ovary 4- or 5-locular; styles erect, thickened and connivent, apically bifid, persisting in fruit as a beak 1–1.5 mm high. Fruits 5–7 mm in diameter, greenish; seed tegmen basally :±: truncate, reddish-brown, 3–5 mm long; hilum 1.2 mm long.

Distribution and Habitat: Costa Rica, mainly in tropical rain forest, 20–900 m; possibly to be encountered in western Panama.

Phenology: Collected in flower May; in fruit January, June, October, November. The label of Poveda 709 indicates that the plant was completely leafless in October.

Additional Specimens Examined: COSTARICA. Limón: Cantón Guácimo, Moravia de Siquierres, c. 200 m, 10° 05′ N, 83° 33′ W, Poveda 709 (MO); Reserva Indígena Codes Talamanca, 3–4 km SW of Pto. Viejo, 100 m, 9° 38′ N, 82° 46′ W, Jimenez et al. 799 (F). Puntarenas: Cantón Golfito, between Bahía Chal and Punta Camíbar, 100 m, 8°44′ N, 83° 00′ W, Aguilar 746 (DAV, F); Parque Nacional Corcovado, Quebrada Vaquedano, 500 m, 8° 39′N, 83° 35.5′ W, Herrera 3993 (DAV); Canton Osa, Osa Peninsula, Agua Buena Oeste, 50 m, 8° 42′ N, 83 °31′ W, Aguilar 1411 (DAV, TEX); Osa Peninsula opposite Golfito, 20–200 m, 8° 38′ N, 83° 11′ W, Schmidt 594 (DAV); Playa Campanario, Sierpe, 1–10 m, 8° 39′ N, 83° 43′ W, Harmon 189 (MO). San José: Valley of El General, 675–900 m, Skutch 5427 (F, US), 5491 (DAV, F).

Burger and Huft (1995) have provided an excellent description of Phyllanthus skutchii. Their reported dimensions of the seeds are much larger than those recorded here, apparently because they included the sarcotesta in their measurements. Phyllanthus skutchii differs from all the other species of sect. Hylaeanthus in its staminate flowers with discrete stamens and (except for P. puntii) its pistillate flowers with erect styles connate into a column.

Dioecious shrub or Tree 5–12 m high; branches cylindrical, smooth and glabrous, lenticellate; branchlets 10–20 (-30) cm long, 0.8–1.5 mm in diameter, cylindrical, smooth and glabrous, sparingly lenticellate, with 8–15 (-20) leaves. Leaf Blades ovate-oblong or elliptic, abruptly acuminate (acumen 0.5–1 cm long), pinnately veined, glabrous or hirtellous on base of midrib adaxially, often puncticulate abaxially; petiole 2–4 mm long, hirtellous (very rarely glabrous); stipules lanceolateacuminate, 1.3–2.2 mm long, deciduous or persistent. Flowers glabrous, greenish, in axillary subsessile or penduculate glomerules, the staminate flowers 20–40 per node, the pistillate 3–10 (rarely 1 or 2 or up to 20) per node. Staminate pedicel (1.5-) 2–3 mm long; sepals 6, elliptic, acute, 0.8–1.5 × 0.3–0.6 mm; disk 6-lobed, 0.5–1 mm in diameter; stamens 3, filaments connate into a column 0.3–0.5 mm high; anthers muticous, dehiscing horizontally, 0.2–0.3 mm long, androecium 0.5–0.6 mm in diameter. Pistillate pedicel becoming 2.5–9 mm long in fruit; sepals elliptic, 0.8–1.7 × 0.8–1.3 mm; disk patelliform or cupular, 1–1.2 mm in diameter; ovary 3- to 6-locular; styles 1–1.3 mm long, basally connate, bifid, branches acute. Fruits 4–7 mm in diameter; seed tegmen c. 3.5–5 mm long, hilum subterminal/lateral.

Phyllanthus attenuatus is the commonest and most widespread species in sect. Hylaeanthus, but due to a mistaken identification by Müller (1866, 1873) it was for nearly a century erroneously considered to be the plant that Aublet described as Meborea guianensis. Lanjouw (1931) pointed out the error, but was undecided as to the affinities of Meborea. Radcliffe-Smith (2001) has correctly placed Meborea guianensis Aubl. in Phyllanthus as P. aubletianus Radcl.-Sm.; that species apparently belongs to Phyllanthus sect. Elutanthos (subgenus Xylophylla).

Three subspecies are recognized within Phyllanthus attenuatus, of which P. a. ssp. attenuatus is the most widespread-from northern Brazil and the Guayanas to Colombia and northern Ecuador. It is replaced by P. a. ssp. tucuruiensis in the Tocantins watershed in Para and by P. a. ssp. incarum in Amazonian Colombia, Ecuador and Peru.

Dioecious (rarely monoecious) Trees; branchlets glabrous; Leaf Blades glabrous except abaxially near junction with petiole; Staminate glomerules usually sessile or subsessile (peduncle mostly ≤ 1 mm long); staminate pedicels 2–4 mm long; pistillate flowers mostly 2–7 (-15) per node; fruiting pedicel glabrous (rarely hirtellous distally), 2–4 mm long; fruiting sepals (1.2-) 1.4–1.8 (-2.1) mm long; ovary 3- or 4- (rarely 5-) locular; seed tegmen (2-) 2.5–3.5 (-4) mm long.

Distribution and Habitat: Northern South America and the Amazon basin, mostly 0–1000 (-1600) m in terra firma rainforests, sometimes in inundated forests (varzea).

Phenology: Collected in flower and fruit throughout the year, with a peak in July.

Additional Specimens Examined. BRAZIL. Amazonas: Mun. Barcelos, margem do rio Aracá, poco abaixo da foz do Rio Jauarí, 00° 25′ N, 63° 25′ W, Cordeiro 250 (DAV, MO, NY); Mun. Manaus, Dto. Agropecuário, 90 km NNE Manaus, 50–125 m, c. 2° 24.5′ S, 59°44′ W, Oliveira et aL 269 (DAV); São Luís, 00° 10′ S, 63° 00′ W, Alencar 149 (NY), Maia 148 (MO). Maranhão: Mun. Carutapera, 5 m, 1° 13′ S, 46°01′ W, Froes 2028 (A, NY). Pará: Mun. Alenquer, Parque Indígena do Tumucumaque, Rio Pará do Oeste, Missão Tiriós, 450 m, 00° 05′ N, 55° 58′ W, Cavalcante 2572 (NY); Mun. Bragança, 13 km N of Bragança, 20 m, 0° 59′ S, 46° 15′ W, Davidse et al. 18022 (DAV); Quatipuru, 0-50 m, c. 1° 05′ S, 46° 45′ W, Rosa 2407 (NY). Roraima: Mun. Alto Alegre, Ilha do Maracá, 300 m, 3° 22′ N, 61° 20′ W, Hopkins et al. 564 (DAV, NY); SEMA Ecological Reserve, Ilha Maracá, 3° 23′ N, 61° 27′ W, Milliken 802 (NY); Mun. Boa Vista, Serra de Tepequém, 1600 m, 3° 45′ N, 61° 45′ W, Silva et al. 422 (DAV); Caracaraí, 100 m, 1° 50′ N, 61° 08′ W, Kuhlmann 1069 (RB 20285).

COLOMBIA. Antioquia: Mpio. Anorí, Río Anorí valley, near Planta Providencia, 350–600 m, c. 7° 15′ N, 75° 00′ W, Shepherd 531 (HUA), 792 (HUA, MO), 400–900 m, 733 (MO); Corr. Providencia, Valle del Río Anorí, entre Dos Bocas y Anorí, 400–900 m, 7° 08′ N, 75° 10′ W, Soejarto et al.4101 (F), 4342 (HUA); Mpio. Gómez Plata (bordering Mpio. Yolombé), Río Poree, 14 km via Amalfi, 1030 m, 6° 45′ N, 75° 05′ W, Callejas et al. 2349 (F, HUA, NY, TEX); Mpio. San Carlos, Corr. Alto Samaná, vereda Miraflores, 880–920 m, 6° 05′ N, 74° 52′ W, Callejas et al. 8553 (MO). Mpio. San Luis, Corr. Monteloro/el Prodigio, 600–950 m, 6° 04′ N, 74° 50′ W, Cárdenas & Ramírez 2577 (MO); Corr. Prodigio, 350 m, 6° 06′ N, 74° 48′ W, Cárdenas & Ramírez 2823 (MO); 350–580 m, Cárdenas et al. 2856 (MO), 500–630 m, 6° 06′ N, 74° 48′ W, Cogollo et al. 4576 (MO); Quebrada La Cristalina, 600–770 m, c. 6° 00′ N, 74° 48′ W, Ramírez & Cárdenas López 1291 (HUA); Vereda Martejales, Cañón del Río Samaná, 300–800 m, 6° 06′ N, 78° 48′ W, Cárdenas et al. 3000 (MO); Mpio. San Rafael, 3 km E of San Rafael, 1110 m, 6° 18′ N, 75° 02′ W, Brant & Roldán 1519 (DAV, F, HUA, MO); Mpio. Segovia Antioquia, salida hacia Doña María. 750 m, c. 7° 05′ N, 74° 45′ W, Renteria et al. 1668 (HUA, MO); Mpio. Tarazá, Corr. El 12, vereda Barroblanco, 350 m, 7° 30′ N, 75° 20′ W, Callejas & McAlpin 1153 (HUA); Mpio. Urrao, vereda Calles, Parque Nacional Las Orquídeas, 14SO m, 6° 32′ N, 76° 14′ W, Cogollo et al. 6572 (DAV, HUA). Bolívar: Mpio. Achi, Ciénaga La Raya, 20–80 m, 8° 20′ N, 74° 30′ W, Callejas et al. 4405 (HUA, MO). Cundinamarca: Mpio. Medina, Mesa Calzón, 6 km NE of Medina, 850 m, 4° 32′ N, 73° 20′ W, Grant 10472 (US). Guainía: Mpio. Puerto Inírida, El Remanso, Cerro de Mavecuri, 300 m, 3° 27′ N, 67° 58′ W, Franco et al. 6130, Rudas et al. 7321 (MO). Meta: Mpio. La Macarena, 20 km NW on road to Conejos, 450 m, 2° 15′ N, 73° 45′ W, Callejas & Marulanda 6965 (HUA, MO); Puerto López, 240 m, 4° 10′ N, 73° 40′ W, Little & Little 8238 (DAV, US); Villavicencio, 500 m, c. 4° 20′ N, 73° 40′ W, Barclay et al. 3616 (DAV, US), Wijninga 524 (MO, NY). Norte de Santander: Mpio. Toledo, región Sarare, Río Cobugón, between Quebrada Gibraltar and La Palma, 320–400 m, c. 7° 03′ N, 72° 05′ W, Cuatrecasas 13238 (F, US).

ECUADOR. Pastaza: Cantón Mera, Mera, 1160 m, 1° 28′ S, 78° 08′ W, Lugo 244 (MO).

GUIANE FRANÇAISE. Cayenne: Cayenne, 0–50 m, 4° 00′ N, S3° 00′ W, Broadway 272 (NY, US), 429 (NY).

GUYANA. [without locality] Schomburgk 977 (US).

SURINAME. Commewijne: Paramaribo, 0–20 m, 5° 50′ N, 55° 10′ W, Wullschlägel 1072 (W). Sipaliwini: Bakhuis Mts., between Kabalebo R. and Coppename W., c. 4° 00′ N, 57° 00′ W, Florschütz & Maas 2748 (DAV); confluence of Paloemeu and Tapanahoni Rivers, 3° 20′ N, 55° 27′ W, Wessels Boer 1249 (F, NY, UC); Wilhelmina Gebergte, Lucie River, 2 km below confluence with Oost Rivier, 225 m, 3° 30′ N, 56° 25′ W, Irwin et al. 55435 (NY, US).

VENEZUELA. Amazonas: Dto. Atabapo, between Cerro Moriche and Las Mercedes, 100–150 m, c. 4° 40′ N, 66° 15′ W, Foldats 100A (US); Salto Yureba, 120–150 m, 4° 03′ N, 66° 01′ W, Delascio & Guánchez 10931 (MO); San Antonio, 120 m, 3° 30′ N, 66° 45′ W, Williams 15037 (US); San Juan de Manapiare, 150 m, 5° 18′ N, 66° 03′ W, Huber 1089 (NY); Santa Bárbara del Orinoco, 3° 57′ N, 67° 04′ W, Berry 652 (MO), Maguire et al. 32013 (MO, NY); Dto. Atures, Isla del Ratón, 100 m, 5° 02° N, 67° 46° W, Breteler 4696 (F, MO, NY, US); Pedra de Cataniapo, 50 km SE of Pto. Ayacucho, 100 m, c. 5° 10′ N, 67° 20′ W, Guanchez 180 (DAV); Raudal de Maypures, 100 m, 5° 10′ N, 67° 47′ W, Spruce 3592 (W); Dto. Río Negro, Esmeralda Ridge, 150–200 m, c. 3° 10′ N, 65°33′ W, Maguire & Maguire 34638 (DAV, NY). Barinas: Dto. Bolívar, Barinitas, 8° 45′ N, 70° 25′ W, Bernardi 3326 (NY); Dto. Pedraza, 8° 31′ N, 70° 35′ W, Dorr 5765 (NY). Bolívar: Dto. Piar, Canaima, Rio Caura, altura del caño Maskani, 6° 16′ N, 62° 51′ W, Stergios & Delgado 12830 (MO). Mérida: Dto. Arzobispo Chacón, km 50 de Sta. María de Chaparo, 3SO m, c. 8° 05′ N, 71° 30′ W, Aymard et al. 4494 (MO, US); Dto. Tovar, Los Giros, near Empresa Río Unio, 700 m, 8° 26′ N, 71° 38′ W, van der Werff & Ortiz 5679 (MO, U). Táchira: Dto. Ayacucho, between San Juan de Colón and Las Cruces, 680 m, 8′ 05′ N, 72° 15′ W, Steyermark 120285 (DAV, MO); Dto. García de Hevia, 4 km W of La Fría, 120 m, 8′ 14′ N, 72° 17′ W, Steyermark et al. 120406 (MO, DAV); Dto. Libertador, Cerro La Espuma, 300–350 m, 7° 34′ N, 72° 05′ W, Steyermark & Leisner 119223 (F), 119289 (MO); 10 km S of El Piñal, 250 m, 7° 27′ N, 71° 55′ W, Davidse & González 21642 (DAV, F, MO); Dto. Panamericano, 10.S km NE of La Fría, 90 m, 8° 16′ N, 72° 10′ W, Steyermark et al. 120547 (DAV, MO); Dto. San Cristóbal, Cava de Calizas, near Pericos, 7 km SW of San Cristóbal, 850–900 m, 7° 42′ N, 72° 54′ W, Bono 5128 (MO). Yaracuy: Dto. Nirgua, near boundary with Dto. San Felipe, 850–990 m, 10° 13′ 40″ N, 68° 37′ W, Meier et al. 8658 (DAV). Zulia: Dto. Catatumbo, Montaña El Mirador, 210 m, 8° 50′ N, 72° 38′ W, Zambrano et al. 1772 (MO); Dto. Colón, Bunting 9830 (NY).

Phyllanthus attenuatus ssp. attenuatus is usually readily distinguished from other taxa of sect. Hylaeanthus by its distinctly caudate-acuminate leaf blades and sessile or subsessile floral glomerules. However, occasional specimens, especially in Colombia, have distinctly pedunculate glomerules, e.g., Callejas & Marulanda 6965 from Meta and Cogollo & Ramírez 2577 from Antioquia. Another specimen from Antioquia (Mpio. San Carlos, Callejas et al. 8553) has completely glabrous leaves as in P. skutchii, but fruits typical for P. attenuatus.

Type: ECUADOR. Orellana: Cantón Orellana, Cañón los Monos-Sachas, árboles dejadas en potreros, 250 m, 0° 25′ S, 76° 55′ W, 8 Oct. 1987, W. Palacios 2095 (Holotype: QCNE!; Isotype: MO!). (Figs. 1, 2d).

Differt ssp. attenuato plantis vulgo monoicis, foliis hirsutulis, glomerulis florum pedunculatis.

Monoecious (rarely dioecious) Trees; Branchlets glabrous; leaf blades hirsutulous abaxially, especially along proximal parts of midrib and veins; Floral glomerules mostly distinctly pedunculate (1–3 mm long); pistillate flowers 2–7 per glomerule, fruiting pedicel glabrous, 4–7 mm long, fruiting sepals 1.3–2 mm long; ovary (4-) 5- or 6-locular; seed tegmen 2.5-4 mm long.

Distribution and Habitat: Lowland primary or secondary terra firme rain forests in Amazonian Colombia, Ecuador and adjacent northern Peru, 150–600 m.

Phenology: Collected in flower and fruit April to November.

Additional Specimens Examined: COLOMBIA. Amazonas: Mpio. Tarapacá, Parque Nacional Natural Amaycayacu, 100 m, 3° 02′ N, 70° 00′ W, Rudas et al. 5215 (MO).

ECUADOR. Orellana: Cantón Orellana, Sector Huashito, 2 km N of Coca, 250 m, 00° 20′ S, 77° 05′ W, Gudiño 185 (MO, QCNE). Pastaza: Cantón Pastaza, Comuna Shuar (Kapawi), 250–300 m, 2° 31′ S, 76° 41′ W, Cerón et al. 4367 (DAV, MO); vía Auca, 115 km S of Coca, S km S of Río Tigüino, 320 m, 1° 15′ S, 76° 55′ W, Rubio 109 (DAV, QCNE), Zak 4045 (DAV). Sucumbíos: Cantón Gonzalo Pizarro, 8 km W of Tumbaque, 500 m, 0° 02′ N, 77° 25′ W, Gentry & Miller 54949 (DAV, MO).

PERU: Amazonas: Prov. Bagua, al lado de Quebrada Sasa, 600 m, 5° 03′ S, 78° 18′ W, Kayap 993 (DAV, US). Loreto: Prov. Maynas, Santa María de Nanay, Quebrada Yarina, 150 m, 3° 55′ S, 73° 40′ W, Vasquez et al. 12188 (MO); Indiana, Explorama Reserve, 105 m, 3° 28′ S, 72° 50′ W, Vasquez & Jaramillo 13158 (MO).

In Pastaza, Ecuador, Phyllanthus attenuatus ssp. incarum approaches the distribution of P. a. ssp. attenuatus but occurs at a lower elevation. Some specimens, especially Cerón et al. 4367 from Pastaza, have very sparsely hirtellous leaf blades, and are somewhat transitional to P. a. ssp. attenuatus. It is possible that contacts (or nearcontacts) with P. a ssp. attenuatus will be found in Pastaza and to the north in provinces Orellana and Napo.

Type: BRAZIL. Pará: Mun. Tucuruí, Breu Branco, 40 km S of Represa Tucuruí, secondary forest on white sand, 90 m, 3° 55′ S, 49° 44′ W, 17 Mar. 1980, T. Plowman, N. A. Rosa, & C. S. Rosario 9692 (Holotype: NY!; Isotypes: F!, MO!). (Fig. 1)

Differt ssp. attenuato ramulis et pedicelis fructigeris pubescentibus, carpelis saepe S vel 6.

Dioecious Tree; Branchlets hirsutulous; Floral Glomerules subsessile to pedunculate (0.5–2 mm); pistillate glomerules with 1 to 5 (-7) flowers; fruiting pedicel 1.5–3 (-5) mm long, hirsutulous or some times glabrous; ovary ( 4-) 5- or 6-locular; seed endotesta (3-) 3.5–4.5 mm long.

Geographical Distribution: Eastern Brazil, in basin of Rio Tocantins (Para), and probably also in Amapa, terra firme forest at elevations of < 100 m.

Phenology: Collected in fruit in March, November.

Additional Specimens Examined: BRAZIL. Amapá: Quadrícula SB-22-VA Ponto 44 [location questionable], Rosa et al. 4155 (DAV, NY). Pará: Mun. Tucuruí, Tocantins, between Marabá and Tucurui, c. 50 m, 5° 00′ S, 49° 20′ W, Jangoux et al. 1697 (NY); margem R. Tocantins, antiga estrada de ferro Alcobaça, Lisboa et al. 1370 (NY).

Subspecies tucuruiensis seems much more similar to and less differentiated from Phyllanthus attenuatus ssp. attenuatus than is ssp. incaruni. However, the pubescence observed on branchlets of P. a ssp. tucuruiensis is rare or absent in populations of ssp. attenuatus in the Guayanas, Venezuela, and Colombia. It seems expedient to recognize P. a. ssp. tucuruiensis as a distinct entity pending more extensive sampling in eastern Amazonia.

Dioecious Tree 6–18 m high; axes glabrous; branchlets terete, smooth (minutely papillate), 15–25 × 1.5–2.5 cm, with 6–9 leaves. Leaf Blades ovate to elliptic, abruptly apiculate, obtuse or rounded at base, 7–13 × 3.5–7 cm, glabrous except for incised midrib adaxially and prominulous midrib and major lateral veins abaxially; veins 5–7 pairs, veinlets prominulous and surface microreticulate abaxially; petiole 5–7 × 1–1.5 mm, copiously scabrid-hirtellous; stipules blackish, triangular, 2–3 mm long. Flowers in axillary sessile or pedunculate (peduncles to 1.5 mm long) glomerules, the pistillate flowers mostly 2–5 per axil; bracts and bractlets blackish, persistent. Staminate flowers (known only in bud): pedicel c. 3 mm long; sepals 6, 1.4–2 × 0.8–1 mm; disk undivided, c. 0.7 mm in diameter; stamens 3, filaments connate into a column c. 0.5 mm high; anthers dehiscing horizontally, androecium c. 0.7 mm in diameter. Pistillate flowers: pedicel glabrous or sparsely and minutely hirtellous, 5.5–10 mm long in fruit; sepals 6 (rarely 5), 2.7–4 × 1.4–2.2 mm in fruit; disk patelliform, c. 1.5 mm in diameter; ovary 3-locular; styles connate into a column c. 1.5 × 0.7 mm; styles bifid, 0.5–0.7 mm long, ± twice-branched. Fruits baccate, 7–9 mm in diameter when dried; seed tegmen somewhat compressed, acute, truncate at base, brownish, 2.5–4 × 2–2.8 mm.

Distribution and Habitat: Endemic to montane rain forests, Colombian Andes, 1000–1850 m.

Phenology: Collected in flower February, July, August, and November; in fruit January, May, and August.

Additional Specimens Examined: COLOMBIA. Antioquia: Mpio. Frontino, Corr. Nutibarra, 5–8 km S of Alto de Cuevas, 6° 39′ N, 76° 25′ W, 1000–1850 m. Callejas et al. 9940 (HUA); cuenca alta del Río Cuevas, 1630 m, Sánchez et al. 994 (M0); Mpio. Urrao, Parque Nacional “Las Orquídeas,” margen del Río Calles, 1450 m, 6° 32′ N, 76° 19′ W, Cogollo et al. 7472 (DAV); 1450 m, 6° 32′ N, 76° 14′ W, Cogollo et al. 6373, 6512 (DAV). Nariño: Mpio. Piedrancha, Corr. Chucunez, Reserva Nat. La Planado, camino hacia Pialapi, 1650–1800 m, 1° 08′ N, 77° 55′ W, Betancur et al. 2576 (HUA).

As noted in the original description (Webster, 2002), Phyllanthus callejasii replaces P. attenuatus at higher elevations (apparently > 1400 m) in the northern Andes of Colombia. It is easily distinguished by its larger broader leaves with a finely reticulate abaxial epidermis. In many ways, it resembles Phyllanthus valleanus Croizat, which appears to be its lowland counterpart.

Type: BRAZIL. Acre: Mun. Sena Madureira, trail to Rio Iaco from km 7 of Sena Madureira-Rio Branco road, 135 m, 9° 05′ S, 68° 39′ W, 1 Oct. 1968, G. T. Prance, D. F. Coelho, J. T. Ramos, & L. G. Farias 7712 (Holotype: U!; Isotypes: A, C, COL, F!, G, INPA, K, M, MG, MICH!, MO!, NY!, P, R, S, US!, VEN). (Figs. 1, 2c, 4b, 5).

Arbor monoica, differt ab aliis speciebus sectionis ramulis foliisque hirtellis et venulis foliorum non prominulis, stylis erectis bifidis exsertis.

Dioecious Tree 8–10 m high; branchlets c. 10–20 cm long, with 10–15 leaves, axis terete, hirsutulous, 0.8–1.5 mm in diameter. Leaf Blades ovate to elliptic, acuminate, obtuse to rounded at base, copiously hirsutulous and micropuncticulate abaxially, and sparsely pubescent adaxially, with 6–8 pairs of lateral veins, midrib and laterals :±: incised adaxially and prominulous abaxially, tertiaries :±: scalariform and at right angles to midrib; petiole mostly 2–5 mm long, copiously hirsutulous both adaxially and abaxially; stipules lanceolate, c. 1.5–2 mm long, hirsutulous. Flowers in pedunculate glomerules, the peduncles 1– 2.5 mm long. Staminate flowers unknown. Pistillate flowers 2–12 (rarely 1) per glomerule; pedicel hirsutulous, 3–5 mm long; sepals 6, abaxially hirtellous (especially at base), 1.3–2 mm long; disk patelliform, crenulate, c. 0.2 mm high and 0.8 mm in diam., ovary (3-) 4- (5-) locular; styles erect, bifid, c. 1–1.5 mm high, connate into a column. Fruits 5–9 mm in diameter; seed tegmen 3–4.2 mm long.

Distribution and Habitat: Presently recorded from the western Amazon (Acre) and lower Andean slopes in Bolivia (La Paz), 135–950 m.

Phenology: Collected in flower (Acre) in October, in fruit (Bolivia) from November to January.

Additional Specimens Examined: BOLIVIA. La Paz: Prov. Larecaja, Copacabana, 10 km S of Mapiri, 850–950 m, 15° 20′ S, 68° 10′ W, Krukoff 11281 (MO); 6.5 km W of Tipuani, 750 m, 15° 36′ S, 68° 01′ W, Solomon 17693 (DAV, MO); 3.2 km SW of Tipuani, 700 m, 15° 35′ S, 68° 00′ W, Solomon 17717 (DAV, MO); Prov. Sud Yungas, Alto Beni, Colonia San Pedro, 520 m, c. 16° 00′ S, 67° 40′ W, Seidel & Vaquiata 7532 (DAV, NY).

It is a great pleasure to dedicate this species to my colleague Willem Punt, who annotated the holotype as a possible new species. This is particularly appropriate in view of the significant contributions to the systematics of Phyllanthus that Dr. Punt has made with his many palynological studies at the Institute of Systematic Botany, Utrecht.

In the indumentum on the abaxial leaf blade surface, Phyllanthus puntii resembles P. attenuatus ssp. incarum; however, it is easily distinguished by its hirsutulous branchlet axes and gynoecium with erect bifid styles, somewhat suggestive of P. skutchii. The type collection from Acre, at a much lower elevation, differs from the Bolivian specimens in a number of features (e.g., larger number of pistillate flowers per glomerule), but there seems little doubt that these disjunct populations are conspecific.

Phyllanthus manausensis W. A. Rodrigues, Acta Amazonica 1: 17, fig. 1. 1971. Type: BRAZIL. Amazonas: Reserva Forestal Ducke, 120 m, 2° 53′ S, 59° 58′ W, 18 Oct. 1963, W A. Rodrigues 7520 (Holotype: INPA 16822!; Isotypes: MO!, NY!). (Figs. 1, 3b).

Monoecious or Dioecious Tree 10–35 m high × 10–20 cm in diameter, glabrous throughout; inner bark reddish, aromatic; branches smooth, furrowed, not lenticellate; branchlets terete, smooth, not (or scarcely) lenticellate, 8–15 cm × 0.5–1 mm, with c. 10–15 leaves. Leaf Blades ovate to elliptic, acute or apiculate to breviacuminate (acumen ≤ 0.5 cm), obtuse to rounded at base, 3–6 × 1.5–3 cm; abaxially copiously puncticulate; midrib incised adaxially, prominently raised abaxially; lateral veins mostly 7–10, veinlets forming an irregular network, slightly prominulous on both faces; petiole 1.5–3 mm long; stipules lanceolate, 0.7–1.5 mm long. Flowers in axillary pedunculate unisexual glomerules (peduncle 1–3 mm long), staminate flowers 30–40 per axil, pistillate flowers 1–4 per axil. Staminate pedicel 2.5–4 mm long; sepals 6, elliptic-oblong, obtuse or subacute, 1.3–1.6 × 0.5–0.8 mm, midrib not prominent; disk 6-angled or ± dissected, 0.7–0.8 mm across; stamens 3, filaments connate into a stout column 0.5–0.7 × 0.3–0.4 mm; anthers ovate, apiculate, dehiscing horizontally, androecium 0.6–0. 7 mm in diameter. Pistillate pedicel slender, 4–7 × 0.1–0.2 mm; sepals 6, elliptic, 1.2–1.7 × 0.6–1 mm; disk patelliform, c. 1 mm in diameter; ovary (3-) 4- or 5-locular; styles erect, slender, unlobed, 0.3–0.5 mm long. Fruits subspheroidal or slightly prolate, 5–8 mm in diameter; seed tegmen 3.5–4.5 mm long.

Distribution and Habitat: Amazonian Brazil, from western Amazonas to Amapá, mostly in terra firme rain forests, 15–300 m.

Phenology: Collected in flower April, September–December, in fruit January, August.

Additional Specimens Examined: BRAZIL. Amapá: Mun. Macapá, 154 km NW of Porto Grande, 1° 30′ N, 53° 30′ W, Rabelo et al. 3089 (DAV, NY); Mun. Mazagão, 81 km WSW of Macapa, 0° 08′ S, 51° 48′ W, Mori & Cardoso 17482 (DAV, F, MO, NY); Mun. Porto Grande, Reserva INCRA, Rio Falsinho, 1° 08′ N, 51° 27′ W, Campbell et al. 10009 (MO). Amazonas: Mun. Humaitá, plateau between Rio Livramento and Rio Ipixuna, c. 50–100 m, 6° 30′ S, 62° 30′ W, Krukoff 7164 (MICH, MO); Mun. Manaus, Igarape Leao, km 12 Manaus-Caracaraí road, 20 m, c. 3° 00′ S, 59° 55′ W, Prance et al. 3825 (DAV, NY); Rio Cuieras, just below mouth of Rio Brancinho, 20–30 m, c. 2° 45′ S, 60° 15′ W, Coelho & Monteiro 14935 (DAV); Reserva Florestal Ducke, 120 m, 2° 53′ S, 59° 58′ W, Assunção 276 (NY); 90 km NNE Manaus, Reserva 1501, Projeto Dinˆmica Biológica de Fragmentos Florestais, 50–125 m, 2° 45′ S, 59° 45′ W, Oliveira et al. 269 (DAV). Pará: Mun. Almeirim, Monte Dourado, área do Felipe VI, c. 1° 15′ S, 52° 50′ W; Pires & Silva 1353 (MO); Mun. Altamira, Forte Altamira, Rio Xingú, 3° 12′ S, 52° 12′ W, Kuhlmann 2037 (RB 20293).

Comparison of the type specimens of Phyllanthus madeirensis Croizat, in western Amazonia, with specimens from the vicinity of Manaus to the mouth of the Amazon, suggests that the plants belong to a single species. Croizat (1944) described P. madeirensis as having 4 or 5 locules in the ovary, whereas Rodrigues (1971) illustrated P. manausensis as having 3 locules. In fact, locule number is variable; and specimens from western and eastern Amazonia agree in their rather small scarcely acuminate leaf blades conspicuously micropuncticulate abaxially, as well as in their rather large seeds. Further sampling in western Amazonia might provide data to justify recognition of two subspecies.

Type: ECUADOR. Carchi: Cantón Tulcán, Parroquia Tobar Donoso, Reserva Indígena Awá, centro El Baboso, bosque premontano muy húmedo, 1800 m, 00° 53′ N, 78° 25′ W, 17–27 Aug. 1992, G. Tipaz, M. Tirado, G. Aulestia, N. Gale, & L. P. Ortiz 1830 (Holotype: QCNE!; Isotypes: DAV!, MO!). (Figs. 1, 6).

Differt ab aliis speciebus sectionis foliis ellipticis ad apicem obtusis vel rotundatis, ramulis pubescentibus, ovario 2-loculare.

Dioecious Shrub 1–6 m high; branches glabrous, terete; branchlets terete, axis densely hirtellous-scabridulous, 8–10 cm × 0.5–0.8 mm, with 10–15 leaves. Leaf Blades broadly elliptic, obtuse to rounded at apex, obtuse at base, 2.5–6 × 2–3 cm; adaxial surface somewhat shiny, both adaxial and abaxial surfaces minutely scabridulous; midrib incised adaxially, prominently raised abaxially; lateral veins 6–10, veinlets mostly perpendicular to secondaries, not raised; petiole terete, rugulose, glabrous, 1.5–2.5 mm long; stipules lanceolate, 0.7–1 mm long, deciduous. Flowers in axillary sessile glomerules, the staminate flowers not seen, pistillate flowers apparently solitary. Pistillate pedicel 8–9.5 mm long, slender (c. 0.1 mm in diameter), glabrous; fruiting sepals obovate-elliptic, 1.2–1.5 mm long; ovary 2-locular; styles connate, entire or emarginate. Fruits broadly ellipsoidal, 5–8 mm in diameter, with stylar beak c. 1 mm long; seed tegmen 1.8–4 mm long.

Distribution and Habitat: Known only from montane cloud forests of Carchi province, Ecuador, 900–1800 m.

Additional Specimen Examined: ECUADOR. Carchi: Cantón Maldonado, Parroq. Tabor Donoso, Reserva Étnica Sabalera, 900 m, Aulestia & Guanga 715 (MO, NY); Cantón Tulcán, Parroquia El Chical, Reserve Étnica Awá, Centro San Marcos, 900–1000 m, 1° 06′ N, 78° 14′ W, Méndez et al. 349 (QCNE).

Phyllanthus awaensis is aberrant within sect. Hylaeanthus in a number of respects. It differs from all other species in the sect. by virtue of its scabridulous branchlet axes bearing completely glabrous leaves. In its small stature and leaf blades with rounded apices, it resembles species of sect. Pityrocladus such as P. symphoricarpoides H.B.K. (cf. synopsis in Webster, 2002). In fact, the venation of P. symphoricarpoides is very similar, especially in the prominulous abaxial midrib and secondaries, to that found in P. awaensis and other species of sect. Hylaeanthus. However, fruiting specimens of P. symphoricarpoides, like other species of sect. Pityrocladus, have a capsular fruit, persistent columella, and seeds lacking a sarcotesta. Furthermore, the pollen grains of P. symphoricarpoides, with 4 or 5 colpi and reticulate exine, are very different from the pollen of sect. Hylaeanthus (Webster & Carpenter, 2002). One can only conclude that there is a striking degree of vegetative convergence in Andean taxa of subgenera Emblica and Conami.

Monoecious Tree, glabrous throughout; bark fissured, reddish internally; branchlets 9–10 cm long, 0.8–1.1 mm in diameter, with 9 or 10 leaves. Leaf Blades broadly elliptical, breviacuminate (acumen ≤ 0.5 cm long), 5–6 × 2.5–3.3 cm, with 5–7 lateral veins, not micropuncticulate abaxially; petiole 3.5–4 mm long; stipules lanceolate, c. 1 mm long, subpersistent. Flowers in sessile or subsessile staminate or bisexual glomerules. Staminate pedicel 2–3 mm long; sepals 6, elliptic; disk patelliform; stamens 3, filaments free or basally connate. Pistillate pedicel 2.5–6 mm long in fruit; sepals 6, obovate, 1.2–1.3 × c. 1 mm in fruit; disk patelliform; ovary 3-locular; styles discrete, bipartite. Fruits 5–7 mm in diameter.

Distribution and Habitat: Colombia in lowland Chocó rain forest, below 100 m.

Phyllanthus valleanus, although known only from the single collection in extreme southwestern Colombia, appears to be a distinct species. It resembles P. callejasii in gross aspect due to the broad abruptly pointed leaf blades, but differs in its completely glabrous leaves, free stamens, and once-branched styles. Furthermore, it grows in Pacific lowland forests as opposed to the Andean rain forests where P. callejasii is found. The overall similarity in vegetative characters suggests that the two species may be related and perhaps derived from divergent ecotypes.

Monoecious Shrub; branches glabrous, sulcate; deciduous branchlets 30–40 cm × 1–1.5 mm, with c. 20–30 leaves. Leaf Blades ovate, acuminate, rounded at base, 5–7 × c. 2.5 cm; glabrous except for proximal midrib adaxially; petioles 2 mm long; stipules c. 1.5 mm long. Flowers in axillary unisexual glomerules, the staminate proximal and pistillate distal. Staminate pedicels c. 5 mm long; sepals 6; disk segments 5 or 6; stamens 3, filaments connate, anther sacs spheroidal, dehiscing :±: horizontally. Pistillate pedicel c. 5 mm long; sepals 6, obtuse, c. 1.3 mm long; ovary 3-locular; styles slender, unlobed, ascending. Fruits and seeds unknown.

This species so far is known only from the type collection, and the description has been adapted from that ofJablonski (1967). Until additional specimens are collected, it will be difficult to evaluate the relationships of Phyllanthus bernardiii. Some characters in the description have been adapted from Croizat's account, and may have to be modified when additional collec;tions are made.

Since Phyllanthus bernardii and P. valleanus are each known from unique localities, they have not been indicated on the distribution map.