Introduction

Theobroma L. (Malvaceae, Byttnerioideae) is native to the Neotropical lowland forests. The genus, in its conventional circumscription (Bernoulli 1869; Cuatrecasas 1964), comprises approximately 20 species of small, understory trees with sympodial growth and large, simple, shortly petiolate leaves. Cauliflory is observed in some species in the genus. The flowers are typically small, measuring no more than 3 cm in diam., with strongly unguiculate and cucullate petals. The petals are divided into two sections: a lower, cucullate portion known as the claw and an upper portion that is often widened and expanded, referred to as the ligule. Additionally, the flowers bear a whorl of five staminodes, alternating with groups of fertile stamens arranged in dyads, triads, or tetrads, commonly referred as “stamens 2-, 3-, or 4-antheriferous” (Bernoulli 1869; Schumann 1886, 1895; Schultes 1958; Cuatrecasas 1964). The fruit, a bacca (see Roth 1977; Spjut 1994), contains a sweet, whitish pulp, corresponding to the inner portion of the mesocarp, within which large purplish seeds are embedded. The seeds are often consumed by humans and other primates (Cuatrecasas 1964).

A closely related group to Theobroma is Herrania Goudot, which was traditionally treated as a separate genus (Goudot 1844; Schultes 1958; Cuatrecasas 1964), but some authors have struggled to distinguish these two genera and, therefore, have included Herrania as a section of Theobroma (Schumann 1886, 1895; Pittier 1930). Unlike Theobroma, Herrania species are predominantly monopodial trees with palmately compound leaves, all exhibiting cauliflory. The morphological structure of petals and the fruits are very similar, except that the ligule in Herrania is filiform and much longer than the claw. The fruits of Herrania also tend to have ten ridges compared to the smooth to five-ridged fruits of Theobroma.

Both Theobroma and Herrania species are predominantly found in western Amazonia, which is recognised as the centre of species richness and endemism for both genera and for Byttnerioideae as a whole (Colli-Silva et al. 2023). Furthermore, western Amazonia stands out for preserving significant areas that have experienced relatively limited human intervention or remain largely untouched, particularly when contrasted with the eastern Amazon region (Myster 2009). It is also anticipated to be home to the highest number of new or yet-to-be-discovered species within the Amazon rainforest, as discussed in Myster (2009).

The monographs by R. E. Schultes and J. Cuatrecasas (Schultes 1958; Cuatrecasas 1964) consolidated the distinct usage of Theobroma and Herrania as two separate, closely related genera based on the characteristics described above. Sections of Theobroma sensu Cuatrecasas (1964), i.e. T. sect. Andropetalum Cuatrec., T. sect. Glossopetalum Bernoulli, T. sect. Oreanthes Bernoulli, T. sect. Rhytidocarpus Bernoulli, T. sect. Telmatocarpus Bernoulli, and T. sect. Theobroma, are mainly defined by stamen arrangement and staminode morphology (Bernoulli 1869; Cuatrecasas 1964). In contrast, in Herrania, the two sections described by Schultes (1958), H. sect. Herrania (Goudot) K.Schum. and H. sect. Subcymbicalyx R.E.Schult., differ in calyx shape, and the calyces are patelliform and cupuliform respectively.

The monophyly of Theobroma has been a source of uncertainty (Whitlock & Baum 1999; Sousa-Silva & Figueira 2005; Borrone et al. 2007; Richardson et al. 2015). However, a recent phylogenetic analysis, which incorporated both molecular and morphological data (Bossa-Castro et al. 2024), has revealed that Theobroma is paraphyletic, with Herrania forming a clade nested within. Furthermore, H. sect. Subcymbicalyx also emerged as paraphyletic. In a subsequent publication, Colli-Silva et al. (2024) recircumscribed Theobroma with six sections: Theobroma sect. Glossopetalum, sect. Herrania, sect. Oreanthes, sect. Rhytidocarpus, sect. Telmatocarpus, and sect. Theobroma. Additionally, T. sect. Herrania comprises three subsections: T. subsect. Dugandia Colli-Silva, subsect. Herrania (Goudot) Colli-Silva and subsect. Subcymbicalyx (R.E.Schult.) Colli-Silva. According to Colli-Silva et al. (2024), T. sect. Herrania subsect. Dugandia, is represented by a single species, T. dugandii (García-Barr.) Colli-Silva, characterised by ovate leaflets with a convex base, entire leaflet margins, and lanceolate staminodes. Theobroma sect. Herrania subsect. Subcymbicalyx consists of six species, mostly distributed in the Amazon Basin, displaying inflorescences with 10 or more flowers, glabrous corolla and petal ligules more than ten times longer than the claw. Lastly, T. sect. Herrania subsect. Herrania encompasses species mostly occurring from North-western South America to the Panama Isthmus and Costa Rica (“Pacific Dominion”, as defined by Morrone 2014), with petal ligules less than ten times longer than the claw. In this work, therefore, we consider Theobroma sensu Schumann (1886; 1895), Ducke (1940) and Pittier (1930) and include Herrania as one of its sections, following Colli-Silva et al. (2024).

During our ongoing taxonomic revision of Theobroma, we have encountered three distinct morphotypes within sect. Herrania. These morphotypes represent three new species: two from subsect. Subcymbicalyx and one from subsect. Herrania. These species are described herein and further information on their recognition, distribution and conservation status is provided.

Materials and Methods

This work is an outcome of an ongoing study of Theobroma sensu lato, which involves compiling and reviewing all available preserved specimen collections for the genus (GBIF.org 2020; see also Colli-Silva et al. 2023). The resultant dataset formed the basis to search and analyse vouchers related to the three newly described species presented in this study. The herbarium collections consulted in this specific species description research included COAH, COL, F, HUA, INPA, K, L, MG, MO, NY, P, RB, U, US, UFACPZ, and WAG (acronyms according to Thiers 2022, continuously updated).

Morphological analyses were based on preserved specimen collections, including fruit collections. Floral parts were rehydrated from dried specimens as necessary. Species descriptions follow the terminology of Ellis et al. (2009) for leaf architecture and Hewson (1988) for leaf indumentum. Flower and fruit morphology terminology was based on Radford et al. (1974), Roth (1977) and Spjut (1994). It should be noted that in Theobroma sect. Herrania, a significant distinguishing feature among species is the extent to which leaf margins, especially the secondary veins, either touch or project beyond the margins of the leaflets. The leaf(-let) venation in most Theobroma species is described as craspedodromous, however, there are species in T. sect. Herrania with margins that are entirely untoothed (or entire) and there are species in which the veins not only touch the leaf margin but also protrude beyond it. The latter results in the formation of apiculate/mucronate structures that vary in conspicuousness. In some cases, these structures are inconspicuous, i.e. less than 2 mm long, while in others they are more prominent, exceeding 2 mm long and the projected veins may bear stellate trichomes.

The list of examined specimens was generated using the “monographaR” package v. 1.2.1 (Reginato 2016) in R Environment (R Core Team 2022). A species conservation status assessment was undertaken using IUCN (International Union for Conservation of Nature) criterion B, with the assistance of the ConR v. 1.3.0 package in R, as outlined by Dauby et al. (2017).

Taxonomic Treatment

1. Theobroma globosum Colli-Silva sp. nov. Type: Brazil, Acre, Tarauacá, Basin of Rio Juruá, Rio Tarauacá, left bank, Reserva Indígena Praia do Carapaná, Seringal Universo, Colocação Vista Alegre, 08°26'58"S, 71°20'57"W, 21 Nov. 1995, fl., D. C. Daly et al. 8666 (holotype UFACPZ!; isotype NY [barcode NY00866026]!).

http://www.ipni.org/urn:lsid:ipni.org:names:77335474-1

Trees 2 – 4 (– 7) m high, growth monopodial; trunk erect, branching near the apex; branchlets tomentose, covered by hyaline, stellate trichomes, ochraceous. Leaves palmately compound, 5 – 7-foliolate, petiolate; stipules linear, caducous, filiform, 1.0 – 3.5 cm long, pubescent, densely covered with long, hyaline, few-branched trichomes; petiole terete, 16 – 40 cm long, 3 – 8 mm in diam. in cross-section, pubescent, densely covered by ferruginous, stellate trichomes with long branches. Leaflets elliptic-obovate, untoothed, 15 – 39 × 4.5 – 14.5 cm, chartaceous, sessile, decurrent at the base, acute at the apex, blade width symmetric, margin entire; venation craspedodromous; minor veins more or less regularly spaced, not reaching the leaf margin, asperous adaxially, tomentose abaxially, trichomes long, few-branched, denser on the major veins, abaxial surface pubescent, densely covered by few-branched and long, stellate trichomes on all the veins and the blade. Inflorescences cauliflorous, fasciculate, growing from the lower portion of the trunk, 4 – 10-flowered. Flowers 5-merous, pedicellate; pedicels 3 – 6 cm long, brownish-black, densely covered by hyaline long stellate trichomes; buds globose, 10 mm in diam. Sepals 3, thick, lanceolate, 10 – 13 × 8 – 10 mm, purple, densely pubescent, trichomes long, hyaline, indumentum stellate dorsally, ventrally covered by minute glandular and hyaline, stellate trichomes, becoming sparser towards the sepal apex. Petals 5, 10 – 15 × 0.8 – 1.0 cm, deeply unguiculate, purple; petal claw 5 – 10 × 10 mm, expanded and concave, cucullate, 6-nerved, pubescent, the adaxial surface densely covered by thick, short, few-branched trichomes, lepidote; ligule linear, 5 – 10 cm long, covered by plate-like trichomes. Androecium pentadelphous, anthers grouped in five tetrads and dyads alternated; filaments connate, forming a staminal tube c. 5 mm long; staminodes 5, petaloid, antipetalous, purple, pubescent, covered by plate-like trichomes, elliptic, 1.0 – 1.5 × 0.5 cm. Gynoecium syncarpous, ovary superior, 5-carpelar and 5-celled, 2.5 mm in diam., tomentose, densely covered by simple to few-branched, hyaline trichomes, axile placentation; style glabrous, 3 mm long. Fruits a bacca, markedly globose, deep-green and glossy when ripe, inner portion of the mesocarp slightly pulpy, brownish-black when dried, 4 – 6 cm in diam., shortly acuminate at the apex; 10-costate, ribs thin, 2 – 5 mm wide; epicarp pubescent, densely covered by small, hyaline, stellate-hispid trichomes said to be irritating, thin. Seeds 20 – 25, 0.6 – 1.0 × 0.3 – 1.0 cm, brownish-black when dried, rhomboid. Fig. 1.

Fig. 1.
figure 1

Theobroma globosum. A branchlet apex with a leaf showing linear stipules (general aspect); B cauliflorous inflorescence; C flower bud, highlighting the indumentum; D open flower; E petal; F staminodial unit, with a central staminode surrounded by two groups of fertile stamens, one with four and the other with two anthers; G gynoecium; H fruit. drawn by bobbi angel.

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recognition. Theobroma globosum is diagnosed by its small, spherical fruits, 4 – 6 cm in diam., with a slightly aculeate apex, differing from the conical fruits of T. asperum (H.Karst. & Triana) K.Schum. ex C.J.J.Hall which are 10 – 12 × 5 – 8 cm without aculeate apices; leaflet margins entire up to the apex (vs minor veins project outside the leaflet margins only at the apex); leaflets entirely tomentose on the abaxial surface (vs asperous); inflorescences with 4 – 10 flowers, (vs more flowers, ranging from 11 to many); flower colour purplish (vs a range of reddish to lilac shades); midrib length shorter than the petiole length.

A number of specimens of Theobroma globosum have been previously identified as T. nitidum (nom. illeg., correct name is T. asperum; see Colli-Silva et al. (2024)), but during our examination of materials from the state of Acre, Northern Brazil, we noted that two distinct morphotypes could be discerned based on leaf and floral features. These were not previously considered by Schultes (1958), although we suspect that Schultes may have described the same taxon at different ranks, using materials from different collections that were actually conspecific.

distribution and habitat. Brazil (Acre, Amazonas states) and Peru (Ucayali province) (Map 1). It grows on the primary terra-firme (non-flooded) forests, close to rivers and poorly drained areas, at elevations of 300 – 350 m.a.s.l.

Map 1.
figure 2

Distribution of Theobroma globosum, T. nervosum and T. schultesii in the Western Amazon basin.

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specimens examined. brazil. Acre: Seringal Fonte Boa, Bacia do Rio Purus, varação para o Seringal Fonte Boa; margem esquerda do Rio Iaco, 10°05'60"S, 69°12'00"W, 28 Oct. 1993, fr., M. Silveira 666 (INPA!, NY!, UFACPZ!, US!); ibid., 09°05'11"S, 68°37'54"W, 2 Oct. 1968, G. T. Prance 7765 (INPA!, MO!, NY!, US!); 09°18'35"S, 70°26'48"W, 21 Oct. 1980, fl., S. R. Lowrie 607 (INPA!, MG!, MO!, NY!, US!); Basin of Rio Juruá, Rio Tarauacá, left bank, Reserva Indígena Praia do Carapaná, Seringal Universo, Colocação Samaúma, 08°23'02"S, 71°17'16"W, 24 Nov. 1995, fl., D. C. Daly 8743 (NY!, UFACPZ!); Basin of Rio Juruá, Rio Tarauacá, left bank, Reserva Indígena Praia do Carapaná, Seringal Universo, Colocação Vista Alegre, 08°26'57"S, 71°20'57"W, 21 Nov. 1995, fl., D. C. Daly 8666 (NY!, UFACPZ!); Rio Juruá, approx. 5 km atrás da villa Porto Walter, 08°18'00"S, 72°46'00"W, 1 Nov. 1991, fr., C. A. Cid-Ferreira 10530 (NY!, US!); Rio Muru, 6 km above confluence with Rio Tarauacá, 08°13'12"S, 70°46'12"W, 16 Sept. 1968, fl., fr., G. T. Prance 7280 (INPA!, K!, MG!, MO!, NY!, U!, US!); Rio Tarauacá, Área Indígena Praia do Carapaná, Seringal Universo, Colocação Estirão, (house of Sr. Cabral Rodrigues da Silva), left bank of the river, 08°25'00"S, 71°19'59"W, 5 Dec. 1995, fl., C. Ehringhaus 331 (NY!, UFACPZ!, US!); Seringal Porongaba, Colocação São José, 10°51'00"S, 68°47'60"W, 1 June 1991, fr., D. C. Daly 6827 (NY!, UFACPZ!). Amazonas: Riosinho Juruema. Rio Jutahy, 4 June 1945, fl., R. L. Froes 21041 (NY!). peru. Ucayali: Purús, Río Curanja, cerca la comunidad nativa Colombiana, 10°03'60"S, 71°05'39"W, 6 July 2002, fl., fr., J. G. Graham 1620 (MO!, NY!, US!).

conservation status. Theobroma globosum has a limited geographical range, AOO = 52 km2; EOO = 88,369 km2 and there are 10 known locations, with the majority of records originating from the state of Acre, Brazil. It is present throughout the state of Acre including some occurrences within protected areas, and the number of locations where it occurs is close to the threshold to define the species as threatened because of its narrow distribution and small AOO, T. globosum meets the criteria for consideration as a threatened species with the provisional status of Vulnerable [VU B2a], based on our assessment, however, it is close to Near Threatened [NT]. Further information, especially concerning continuing population decline, is needed for a full assessment of this species.

phenology. Flowering has been recorded from September to December, fruiting from July until October.

etymology. The name is a reference to the globose fruit, remarkable in this species and an uncommon feature of Theobroma sect. Herrania from the Amazon Basin.

notes. Theobroma globosum should be placed in T. sect. Herrania subsect. Subcymbicalyx, based on corolla indumentum, the presence of secondary veins that extend beyond the leaf margin, the formation of inflorescences with a small number of flowers, and the petal ligule 10× longer than the claw.

2. Theobroma nervosum Colli-Silva sp. nov. Type: Ecuador, Napo, Finca del Roque, Mentura Yumbo, 5 km al SE of La Joya de Las Sachas, 13 Oct. 1986, fl., M. A. Baker et al. 7121 (holotype MG!; isotype NY [barcode NY01691973]!).

http://www.ipni.org/urn:lsid:ipni.org:names:77335472-1

Trees 3 – 6 m high, monopodial growth; trunk erect, branching near the apex; branchlets densely tomentose, covered by hyaline, stellate trichomes with long branches, ochraceous. Leaves palmately compound, 5 – 7-foliolate, petiolate, stipulate, stipules persistent, linear-lanceolate, 0.8 – 3.5 cm long, pubescent, densely covered with long, hyaline, few-branched trichomes; petiole terete, 12 – 26 cm long, 5 – 10 mm in diam. in cross section, hirsute, covered by hyaline, stellate trichomes with long branches. Leaflets obovate, entire, occasionally irregularly lobed towards the base, 17 – 37 × 7 – 13 cm, chartaceous, sessile, blade width symmetric, margin toothed; secondary venation craspedodromous; secondary veins more or less regularly spaced, veins projecting beyond the leaf margin, forming apiculate structures 0.8 – 3.5 (– 5.0) mm long, distributed all along the leaflet margin but more abundant apically, densely covered by simple to few-branched hyaline trichomes, adaxial surface asperous, sparsely covered by white, simple to few-branched trichomes, mainly centred in the primary and secondary veins, abaxial surface tomentose, densely covered by long, stellate trichomes, found along the main veins and sparsely distributed on the leaf blade. Inflorescences cauliflorous, fasciculate, 4 – 10-flowered, growing from the lower portion of the trunk. Flowers 5-merous; pedicellate; pedicels c. 1.5 – 2.5 cm long, ferruginous, densely covered by hyaline, stellate trichomes; buds globose, 10 – 12 mm in diam. Sepals 3, lanceolate, 13 – 15 × 8 – 10 mm, ochraceous-ferruginous, tomentose, sparsely covered by long, hyaline, stellate trichomes dorsally, ventrally covered by minute, hyaline, stellate and glandular trichomes centred at the base and becoming less abundant towards the sepal apex. Petals 5, 45 – 70 × 8 – 10 mm, unguiculate, purplish; petal claw 3 – 8 × 8 – 10 mm, expanded, concave, cucullate, 6 – 7-nerved, pubescent, adaxial surface densely covered by thick, short, few-branched trichomes, lepidote, abaxial surface glabrous; ligule linear, glabrous, 4.5 – 7.0 cm long. Androecium pentadelphous, anthers grouped in five alternating triads and tetrads; filaments connate, forming a staminal tube c. 5 mm long; staminodes 5, petaloid, antipetalous, purplish, glabrous, elliptic, 2.0 – 2.5 × 0.4 – 0.6 cm. Gynoecium syncarpous, style glabrous, 3 mm long, ovary superior, 5-carpelar and 5-celled, 2.5 mm in diam., tomentose, densely covered by simple to few branched hyaline trichomes, axile placentation. Fruits a bacca, brownish-black when dried, probably yellowish-green when ripe, 8.0 – 9.0 × 3.0 – 3.5 cm, 2.0 – 3.0 cm in diam., elliptic-conic, acuminate at the apex; 10-costate, major ribs protruding, acute, 5 – 8 mm, minor ribs 2 – 5 mm; epicarp pubescent, densely covered by small, hyaline, stellate-hispid trichomes; pericarp 5 – 10 mm thick, scarcely pulpose. Seeds 20 – 30, 0.6 – 1.5 × 0.3 – 1.0 cm, brownish-black when dried, rhomboid. Fig. 2.

Fig. 2.
figure 3

Theobroma nervosum. A leaf (general aspect), highlighting B cauliflorous inflorescence; C fully open flower, emphasising the secondary veins projecting beyond the leaflet margin, forming apiculate structures and highlighting the indumentum; D close-up of leaves on a branchlet, showing stipules; E fruit. drawn by bobbi angel.

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recognition. Theobroma nervosum is diagnosed by its toothed leaflets and minor veins projecting beyond the leaflet margins, forming conspicuous apiculate structures with trichomes 3 – 6 mm long, found all along the leaflet margins. Theobroma nervosum resembles T. kanukuense (R.E.Schult.) Colli-Silva, a species from the Guiana Shield. However, there are noticeable differences between the two, in T. nervosum, the secondary veins irregularly extend beyond the leaflet margin, particularly towards the leaflet apex, whereas in T. kanukuense, the secondary veins that project outside the leaflet margin are longer and evenly distributed along the entire leaflet margin.

Vegetatively, Theobroma nervosum also shares similarities with T. cuatrecasasianum (García-Barr.) Colli-Silva, which also features toothed leaflets, with secondary veins projecting beyond the leaflet margin. However, several distinguishing features set T. nervosum apart from T. cuatrecasasianum, these include differences in leaflet shape (elliptic-oblong in T. cuatrecasasianum, never lobed, vs ovate in T. nervosum, occasionally lobed), the length of protrusion of the secondary veins from the leaflet margin (up to 2 mm, vs 2 – 3 (– 5) mm). The flowers differ in the number of flowers in the inflorescence (10 or more in T. cuatrecasasianum, vs 4 – 10 flowers in T. nervosum).

distribution and habitat. Theobroma nervosum is found in Colombia (Antioquia, Caquetá, Chocó, and Putumayo provinces) and Ecuador (Napo, Orellana, and Sucumbíos provinces) (Map 1). It primarily grows in the understory of terra-firme forests in Amazonia and occurs at low elevations, typically ranging from 200 to 350 m above sea level, mostly on clay-rich and humid soils.

specimens examined. colombia. Antioquia: Caracolí, Cercanías de la planta hidroeléctrica Inmarco, quebrada Farallones, 06°17'57"N, 74°42'20"W, 24 April 2004, J. Benavides & C. Lopez 3027 (HUA!); Puerto Berrío, Bosques de la Estación Experimental Tulenapa - CORPOICA, 06°21'58"N, 74°33'36"W, 24 Sept. 2004, R. Fonnegra et al. 8664 (HUA!). Caquetá: Belén de los Andaquíes, Parque bosque Microcuenca La Resaca, 01°36'N, 75°54'W, 28 Oct. 2010, fl., D. Cardenas et al. 40850 (COAH!); ibid., Rio Caguán, 22 April 1953, P. C. Holliday & F. W. Cope 110 (COL!, K!). Chocó: Acandí, Corregimiento Capurganá, bahía El Aguacate, Reserva Natural El Aguacate, 08°36'58"N, 77°19'41"W, 23 July 2008, fr., S. Hoyos et al. 804 (HUA!). Putumayo: Mocoa, Corregimiento de Arusí, Estación Bilógica El Amargal, 01°04'48"N, 76°37'12"W, 27 April 2010, G. A. Pantoja & O. Ortega 305 (COAH!). ecuador. Napo: Finca del Roque, Mentura Yumbo, 5 km al SE of La Joya de Las Sachas, 13 Oct. 1986, fl., M. A. Baker et al. 7121 (type; MG!; NY!). Orellana: along old pipeline road from continental divide, 10 July 1993, fr., G. A. Tipaz et al. 2715 (MO!); Vereda El Trueno, Estación Experimental El Trueno, SINCHI, 4 Dec. 1992, fr., D. A. Neill et al. 10160 (MO!, US). Sucumbíos: Parroquia Limoncocha, 00°22'26"S, 76°33'08"W, 22 March 2004, D. Reyes et al. 374 (MO!, US!); Parroquia Santa Cecilia, Rio Aguarrico, Santa Cecilia rain forest, on trail to La Cocha, 00°04'12"N, 76°58'12"W, 23 Nov. 1966, B. Sparre 13047 (MO!); Río Arajuno Sola Cocha Bosque muy húmedo Tropical Suelo rojo arcilloso (ultisol); colinas pendientes, 25 Oct. 1991, fl., fr., W. A. Palacios 9530 (MO!, US!); Muñozlandia on Rio Aguarico, 45 minutes walk on trail W near river, 12 Oct. 1971, fl., B. MacBryde 1168 (MO!); Orellana Parque Nacional Yasuní, Carretera y oleoducto de Maxus en construcción, km 27, 4 July 1993, fl., M. Aulestia et al. 35 (MO!, US!); Rio Aguarrico, Santa Cecilia Muñoz, 26 Nov. 1966, fr., B. Sparre et al. 13156 (MO, NY!).

conservation status. Theobroma nervosum has a limited geographical range, its AOO is 36 km2; EOO is 20,478 km2 and there are 9 known locations. Some records are within protected areas, both in Colombia and Ecuador. No significant threats are known to affect the species, apart from its traditional use (likely not detrimental to the population) by riverine communities in Ecuador. However, the restricted range of T. nervosum may warrant the provisional assessment of this species (IUCN 2019) as Vulnerable [VU B2a], following IUCN (2012) criteria, a determination that requires substantiation in a full assessment.

phenology. Flowering has been recorded mostly from October to December, fruiting in July.

etymology. The name derives from the leaflet margin containing secondary veins that extend beyond the leaflet edges, giving rise to apiculate structures. In Theobroma, this feature is exclusive to certain members of T. sect. Herrania, such as T. pulcherrimum (Goudot) De Wild. However, in T. nervosum, this feature is remarkably conspicuous.

notes. Theobroma nervosum should be placed in T. sect. Herrania subsect. Subcymbicalyx, as it has the same set of features as those detailed for T. globosum.

3. Theobroma schultesii Colli-Silva sp. nov. Type: Ecuador, Napo, Villano, near Rucu Llacta, 2 Aug. 1990, fl., B. C. Bennett & R. Alarcon 4398 (holotype NY!, isotype US!).

http://www.ipni.org/urn:lsid:ipni.org:names:77335473-1

Trees 2.5 – 8.0 m high, monopodial growth; trunk erect, branching near the apex; branchlets densely tomentose, covered by ochraceous, stellate trichomes. Leaves palmately compound, 5-foliolate, petiolate, stipulate; stipules caducous, linear-lanceolate, 1.0 – 1.5 cm long, pubescent, densely covered with ochraceous, few-branched trichomes; petiole semi-terete, 32 – 60 cm long, 8 – 12 mm in diam. in cross section, tomentose, covered by hyaline, stellate trichomes with long branches. Leaflets elliptic-lanceolate, untoothed, 30 – 41 × 10 – 15 cm, chartaceous, petiolulate; petiolule 4 – 7 mm long, blade width symmetric (asymmetric in younger branches); venation craspedodromous; secondary vein spacing decreasing proximally, adaxial surface glabrous, asperous, except for the midvein which is densely covered by hyaline, stellate trichomes, abaxial surface tomentose, sparsely covered by hyaline, mostly long, stellate trichomes, both on the primary and secondary veins and on the leaf blade. Inflorescence cauliflorous, fasciculate, 4 – 10-flowered, growing from the lower portion of the trunk. Flowers 5-merous, pedicellate; pedicels c. 1.0 – 2.0 cm long, ferruginous, densely covered by stellate trichomes; buds globose, cupuliform, 10 – 12 mm in diam. Sepals 3, lanceolate, 13 – 15 × 8 – 10 mm, ochraceous-ferruginous dorsally, purplish ventrally, tomentose, sparsely covered by long, hyaline, indumentum stellate trichomes dorsally, ventrally covered by minute, white, stellate, glandular and plate-like trichomes mostly found at the base, becoming sparse towards the sepal apex. Petals 5, 10 – 15 × 8 – 10 cm, unguiculate, crimson; claw 1.0 – 1.3 × 1.0 cm, expanded, concave and strongly cucullate, 7 – 8-nerved, pubescent, densely covered by plate-like to glandular trichomes especially on the ventral surface; ligule linear, membranous, glabrescent, 9.0 – 13.7 cm long. Androecium pentadelphous, stamens grouped in alternating tetrads and dyads; filaments connate, forming a staminal tube c. 5 mm long; staminodes 5, petaloid, crimson to purple, densely covered by plate-like and glandular trichomes on both surfaces, elliptic, 2.0 – 3.5 × 0.5 cm. Gynoecium syncarpous; style glabrous, 3 mm long; ovary superior, 5-carpelar and 5-celled, 2.0 – 2.5 mm diam., tomentose, densely covered by stellate, long-haired, hyaline trichomes, axile placentation. Fruits a bacca, brownish when dried, yellowish-green when ripe, 10.0 – 17.5 × 3.5 – 7.0 cm, 3.0 – 5.0 cm in diam., conic, acute to mamillate at the apex; apex 1.5 – 3.5 cm long; 10-costate, primary ribs protruding, acute, 1 mm, minor ribs 2 – 4 mm; epicarp pubescent, densely covered by small, hyaline, stellate-hispid trichomes; pericarp 2 – 4 mm thick, slightly pulpose. Seeds c. 30 – 35, 0.6 – 0.8 × 0.2 – 0.6 cm, brownish-black when dried, rhomboid. Fig. 3.

Fig. 3.
figure 4

Theobroma schultesii. A leaf (general aspect), highlighting the indumentum on the abaxial surface, a stellate trichome and the leaflet margin, B flower; C petal; D androecium unit, with a central staminode surrounded by two groups of fertile stamens, one with four and the other with two anthers; E gynoecium; F fruit. drawn by bobbi angel.

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recognition. Theobroma schultesii is diagnosed by having both petiolulate and untoothed leaflets and a cupuliform calyx, densely covered by plate-like trichomes which extend throughout the androecium and the base of the petals. Vegetatively, T. schultesii shares similarities with T. umbraticum (R.E.Schult.) Colli-Silva and T. pulcherrimum (Goudot) De Wild. Theobroma schultesii resembles T. umbraticum in having petiolulate leaflets with an entire margin. However, the floral characteristics of these species differ significantly, T. umbraticum has a patelliform calyx (vs cupuliform in T. schultesii) with smaller petals (1.5 – 2.0 cm long) included within the calyx (vs longer petals, 10 – 15 cm long, not included in the calyx). In comparison to T. pulcherrimum, T. schultesii has similar fruit characteristics, but its leaflets are entire and petiolulate (vs decurrent at the base in T. pulcherrimum) and the inflorescence is 4 – 10-flowered 1 (vs 11 or more-flowered). Furthermore, T. schultesii bears crimson flowers and T. pulcherrimum purplish flowers.

distribution and habitat. Colombia (Meta province), Ecuador (Esmeraldas, Morona Santiago, Napo, Orellana, Pastaza, and Sucumbíos provinces) and Peru (Amazonas, Iquitos, and Loreto provinces), growing in terra-firme forests, sometimes on disturbed sites, intermediate between temporarily inundated and upland forests (Map 1).

specimens examined. colombia. Meta: La Macarena, Río Duda, P.N.N Tiniguas, 25 Jan. 1992, fr., T. Ohba 1109 (MO!). ecuador. Esmeraldas: Bellavista, Jardín de la Plaza Los Caros Facultad de Ciencias UCV Los Chaguaramos, 00°22'48"N, 79°25'48"W, 26 April 2003, fl., X. F. Cornejo et al. 7730 (US!). Morona Santiago: Bomboiza, Bosque cerca a Rio Bomboiza, 03°27'23"S, 78°33'06"W, 27 Aug. 1985, fr., N. Trushell et al. 1318 (MO!, NY!); Kankaim, 16 Sept. 1985, fr., K. S. Lowell et al. 499 (NY!); Sucúa, Villano, near Rucu Llacta, 02°30'00"S, 78°07'48"W, 12 March 1990, fl., B. C. Bennett et al. 4055 (NY!). Napo: Reserva Biológica Jatun Sacha, Río Napo, 8 km al E de Misahuallí, 21 May 1987, fr., C. E. Ceron et al. 1438 (MO!, US); San Pedro, District Isle of San Rafa; in front of village of Ahuano, 01°06'00"S, 77°34'48"W, 16 May 1991, M. Rios et al. 348 (NY!, US!); Venecia Derecha, Pastaza Curaray Ridge NE of Destacamento, 01°03'S, 77°41'W, 13 Aug. 1979, fl., fr., L. B. Holm-Nielsen et al. 19294 (MO!, NY!); Nucuno, Villano, near Rucu Llacta, 00°54'00"S, 77°45'00"W, 2 Aug. 1990, B. C. Bennett et al. 4398 (type; NY!, US); Orellana: Francisco de Orellana, Huampami, Río Cenepa, 00°28'00"S, 76°48'60"W, 26 March 1980, fl., J. S. Brandbyge et al. 30341 (K!, MO!). Pastaza: Montalvo, Trapecio, cerca Tabatinga in frontier with Brazil, 01°45'00"S, 76°49'59"W, 14 Dec. 1995, fl., fr., D. D. Soejarto et al. 9413 (F!). Sucumbios: Lago Agrio, Dureno, comunidad indígena Cofán, águas abajo del Río Aguarico, hasta localidad denominada Aguarico 3, 23 Dec. 1985, fr., C. E. Ceron 141 (MO!); ibid., Bilsa Biological Station, Mache-Chindul Ecological Reserve, 25 Nov. 1999, fl., fr., D. A. Neill 12201 et al. (MO, US!); Cordillera del Cutucú Parte alta del Río Shacham Entza Terreno colimado, 14 April 2002, fr., L. Suin et al. 1567 (MO!); Hacienda San Antonio de Baron von Humboldt, 2 km al NE de Mera, 20 Feb. 1985, fl., W. A. Palacios et al. 30 (MO!); ibid., Río Curaray, Costada sur, Boca del Río Querano, 12 Oct. 1985, D. A. Neill et al. 6909 (MO!); Putamayo R., 15 Aug. 1957, fl., fr., H. G. Barclay et al. 4944 (COL!, MO!); ibid., H. G. Barclay 4981 (MO!); ibid., Río Pastaza, Quihuaro Territorio Huorani, 6 Jan. 1995, fl., J. S. Miller et al. 752 (MO!). peru. Amazonas: Condorcanqui, Strip between calle Piura and the Rio Santiago, in La Poza, 18 Oct. 1979, B. Berlin 3695 (MO!). Iquitos: Quistococha, 23 June 1979, F. Ayala 1877 (MO!). Loreto: Rio Yubineto, tributary of Rio Putumayo, 22 March 1978, C. Hexaire 2970 (MO!); ibid., 15 July 1978, fl., fr., J. Gasche & S. Poulain 5165 (MO!); Distrito Las Amazonas, Quebrada Sucusari, 11 Aug. 1994, fl., R. Ortiz et al. 83 (MO!).

conservation status. Theobroma schultesii has quite an extensive geographical range, AOO is 80 km2; EOO is 260,457 km2 and it has 18 known locations. Several occurrences have been noted within protected areas and there are no indications of specific threats to the locations. Based on IUCN (2012, 2019) guidelines, this species is provisionally assessed as Near Threatened [NT], since it may be Least Concern [LC] if weight is given to the EOO and absence of known, direct threats, or Vulnerable [VU] given its small AOO and the general threats to its habitat.

phenology. Flowering between April to August; fruiting recorded between January and July.

etymology. The name is a reference to Dr Richard E. Schultes (1915 – 2001), an American biologist, botanist and ethnobotanist famous for his studies of plant uses by indigenous people, especially those from Amazonia. Schultes also contributed to the taxonomy of Theobroma sect. Herrania by describing several species during his career (Schultes 1942, 1943, 1950, 1954), that ultimately culminated in the publication of a monograph of the genus (Schultes 1958).

notes. Theobroma schultesii should be placed in T. sect. Herrania subsect. Herrania, due to its untoothed leaflet margins, with secondary veins that do not extend beyond the leaflet margin and petal ligules less than 10× longer than the claw. The distribution of this species is not typical of the other species of the same subsection which usually extend more towards the Northern-Northeastern Pacific South America, Panama and Costa Rica.