Synopsis of Trichosanthes (Cucurbitaceae) based on recent molecular phylogenetic data

Abstract Abstract

The snake gourd genus, Trichosanthes, is the largest genus in the Cucurbitaceae family, with over 90 species. Recent molecular phylogenetic data have indicated that the genus Gymnopetalum is to be merged with Trichosanthes to maintain monophyly. A revised infrageneric classification of Trichosanthes including Gymnopetalum is proposed with two subgenera, (I) subg. Scotanthus comb. nov. and (II) subg. Trichosanthes, eleven sections, (i) sect. Asterospermae, (ii) sect. Cucumeroides, (iii) sect. Edulis, (iv) sect. Foliobracteola, (v) sect. Gymnopetalum, (vi) sect. Involucraria, (vii) sect. Pseudovariifera sect. nov., (viii) sect. Villosae stat. nov., (ix) sect. Trichosanthes, (x) sect. Tripodanthera, and (xi) sect. Truncata. A synopsis of Trichosanthes with the 91 species recognized here is presented, including four new combinations, Trichosanthes orientalis, Trichosanthes tubiflora, Trichosanthes scabra var. pectinata, Trichosanthes scabra var. penicaudii, and a clarified nomenclature of Trichosanthes costata and Trichosanthes scabra.

Introduction

Background

Trichosanthes L. is the largest genus in the Cucurbitaceae family, with over 90 species. The genus has its center of diversity in Southeast Asia, but ranges from India throughout Asia east to Taiwan, the Philippines and Japan, and southeast to New Guinea, Australia, Fiji and Vanuatu (de Wilde and Duyfjes 2010). The snake gourd (Trichosanthes cucumerina L.) is a popular vegetable in South and Southeast Asian cuisine and cultivated in tropical and subtropical regions around the globe. Gymnopetalum Arn. includes four species (de Wilde and Duyfjes 2006) and ranges from India through China and Southeast Asia into the Malay archipelago, but does not occur in New Guinea and Australia (de Wilde and Duyfjes 2010).

Morphology and classification

Trichosanthes are mostly stout perennial climbers, 3–30 m long, dioecious, less frequently monoecious, with branched tendrils, distinctly fringed petals, and often egg-sized brightly colored fruits. Dioecy, variation in vegetative morphology (esp. in juvenile plants), and incomplete herbarium collections, complicate taxonomical studies and have contributed to the description of nearly 300 taxa (de Wilde and Duyfjes 2010; IPNI 2011).

No full taxonomic treatment of the genus exists, but in recent years regional revisions have been published for most of its distribution: India (Chakravarty 1959; Jeffrey 1980a; Jeffrey 1982), China (Lu et al. 2011; Yueh and Cheng 1974; Yueh and Cheng 1980), Thailand (Duyfjes and Pruesapan 2004), Cambodia, Laos and Vietnam (Keraudren-Aymonin 1975), Malaysia, Indonesia, the Philippines and Papua New Guinea (Rugayah and de Wilde 1997; Rugayah and de Wilde 1999; de Wilde and Duyfjes 2004; de Wilde and Duyfjes 2010), Australia (Telford 1982; Cooper and de Boer 2011) and Japan (Ohba 1984).

Infrageneric classifications of the genus Trichosanthes have been proposed by various authors (Yueh and Cheng 1974; Jeffrey 1980b; Chen 1985; Huang et al. 1997; Rugayah and de Wilde 1999; de Wilde and Duyfjes 2004). The most recent classifications of the genus (Rugayah and de Wilde 1999; de Wilde and Duyfjes 2004) propose six sections: (i) sect. Trichosanthes, (ii) sect. Cucumeroides (Gaertn.) Kitam. including subsect. Cucumeroides (Gaertn.) Kitam. and subsect. Tetragonosperma (C.Y.Cheng & Yueh) Rugayah, (iii) sect. Edulis Rugayah, (iv) sect. Foliobracteola C.Y.Cheng & Yueh, (v) sect. Involucraria (Ser.) Wight including subsect. Bracteatae C.Jeffrey ex S.K.Chen and subsect. Pedatae (C.Y.Cheng & Yueh) C.Jeffrey ex S.K.Chen, and (vi) sect. Asterosperma W.J.de Wilde & Duyfjes. However, both Rugayah and de Wilde (1999) and de Wilde and Duyfjes (2004; 2010) are reserved in their infrageneric classifications, and mention a need for further investigation.

Pollen morphology has also been used for infrageneric classification in the genus (Khunwasi 1998; Pruesapan and Van Der Ham 2005; Huang et al. 1997), but as a character is very variable in Cucurbitaceae, and its taxonomic value is not clear (Schaefer and Renner 2011). Palynological studies (Pruesapan and Van Der Ham 2005) have indicated that a variety of pollen types exist in Trichosanthes including 3(-4)-porate and 3(-4)-colporate pollen with psilate, perforate, verrucate, reticulate, and regulate ornamentation. Their study of pollen from 37 species distinguishes five pollen types, two of which are further divided into subtypes, and categorized these using exine ornamentation patterns for the major types and ectoaperture characters for the subtypes.

Gymnopetalum strongly resembles certain Trichosanthes species, but lack thread-like fringes on the petals, and the overall shape of the folded petals in the mature bud is elongate (short and rounded in Trichosanthes) (de Wilde and Duyfjes 2006). A revision of the genus was published by de Wilde and Dufyjes (2006), with minor nomenclatural changes published later (de Wilde and Duyfjes 2008). Cogniaux (1881) divided Gymnopetalum into two sections, (i) sect. Gymnopetalum containing the type Gymnopetalum tubiflorum (Wight & Arn.) Cogn. from southern India and Sri Lanka, and (ii) sect. Tripodanthera (M.Roem.) Cogn. containing the Southeast Asian and Malesian species. Later authors did not follow this classification (Jeffrey 1980a; Philcox 1997; de Wilde and Duyfjes 2006).

Recent molecular phylogenetic studies

The molecular phylogenetic study of Trichosanthes by de Boer et al. (Submitted) shows that Trichosanthes and Gymnopetalum are both non-monophyletic, but together form a clade with high support in the Bayesian tree and weak support in the ML tree (0.99/62). This indicates that Gymnopetalum should be merged with Trichosanthes, and that a revised infrageneric classification is necessary. Some previously recognized sections in Trichosanthes and Gymnopetalum are well supported, but others need to be described or redefined.

Results and discussion

Molecular phylogeny

The molecular phylogeny of Trichosanthes and Gymnopetalum by de Boer et al. (Submitted) has nomenclatural implications for the species in Gymnopetalum and the infrageneric classification of Trichosanthes. The species of Gymnopetalum are placed in different clades within Trichosanthes, with the sect. Gymnopetalum, including the type Gymnopetalum tubiflorum, grouping in a well-supported clade (1.00/84) together with species of sect. Trichosanthes and sect. Cucumeroides. The sect. Tripodanthera, consisting of the three other species in the genus, Gymnopetalum orientale W.J.de Wilde & Duyfjes, Gymnopetalum chinense (Lour.) Merr., and Gymnopetalum scabrum (Lour.) W.J.de Wilde & Duyfjes, forms a well-supported clade (1.00/86) together with the taxa in Trichosanthes sect. Edulis.

Within Trichosanthes the support for the two clades here defined as subgenera Trichosanthes (1.00/94) and Scotanthus (1.00/97) is high. However,splitting the genus into two genera corresponding to subg. Scotanthus and subg. Trichosanthes would not improve clarity, as both would consist of species with fringed and fringeless corollas. Maintaining a large Trichosanthes is in accordance with the recent taxonomic revisions of the genus (de Wilde and Duyfjes 2010; Chakravarty 1959; Lu et al. 2011; Duyfjes and Pruesapan 2004; Keraudren-Aymonin 1975; Cooper and de Boer 2011; Ohba 1984), and is the alternative that best provides taxonomic stability.

Some proposed sections in Trichosanthes and Gymnopetalum are well supported: (i) sect. Cucumeroides (1.00/93), including subsect. Cucumeroides (0.99/-) and subsect. Tetragonosperma (0.99/69), (ii) sect. Edulis (1.00/75), and (iii) sect. Asterosperma (1.00/100). The subsections of sect. Cucumeroides are statistically supported, but subsect. Cucumeroides consists solely of accessions of Trichosanthes pilosa Lour. and species that have been reduced to its synonymy (Cooper and de Boer 2011). Sect. Involucraria is only weakly supported (0.83/65), primarily due to the low support for inclusion of its type, Trichosanthes wallichiana (Ser.) Wight. The subsections of Involucraria are not supported, and taxa belonging to subsect. Pedatae are nested in different locations within subsect. Bracteatae. Sect. Tripodanthera is not supported by the analysis, and could possibly form a grade at the base of sect. Edulis. However, morphological support for this section is strong as all taxa share characters of flower morphology, i.e. fringeless corollas. Sect. Foliobracteola Cheng & Yueh, which in its original sense included the species related to Trichosanthes kirilowii Maxim. and Trichosanthes villosa Blume (Yueh and Cheng 1974; Rugayah and de Wilde 1999; de Wilde and Duyfjes 2004), is not supported. However, a clade consisting of Trichosanthes kirilowii Maxim., Trichosanthes miyagii Hayata, Trichosanthes homophylla Hayata, Trichosanthes hylonoma Hand.-Mazz., Trichosanthes rosthornii Harms, and Trichosanthes multiloba Miq. is strongly supported (1.00/99). Section Truncata, in its original sense including Trichosanthes truncata C.B.Clarke, Trichosanthes kerrii Craib, Trichosanthes homophylla Hayata (Yueh and Cheng 1980), and Trichosanthes smilacifolia C.Y.Wu (Jeffrey 1980b), is not supported, as the three latter species all end up elsewhere in the phylogenetic tree.

Trichosanthes villosa was placed in sect. Involucraria by Yueh and Cheng (1974), and later in subsect. Involucraria by Jeffrey (1980b), but subsequently moved to sect. Foliobracteola by Rugayah and de Wilde (1999). In the protologue of Trichosanthes phonsenae Duyfjes and Pruesapan (2004), the authors stated that the three species Trichosanthes kerrii, Trichosanthes phonsenae and Trichosanthes villosa form a coherent, distinct group based on presence of white fruit pulp, male flowers with the stamens inserted low in the receptacle tube, and a pseudo-ovary. The molecular evidence shows that all accessions of these species in this study form a well-supported monophyletic group, confirming the observations by Duyfjes and Pruesapan (2004) and warranting placement of these taxa in a new section, sect. Pseudovariifera H.J.de Boer.

Cooper and Ford (2010) and Cooper and de Boer (2011) placed Trichosanthes subvelutina F.Muell. ex Cogn. in section Foliobracteola as it has obovate seeds with an entire broad marginal band similar to those found in Malesian species of section Foliobracteola. However, Huang et al (1997) proposed to place it in section Foliobracteola subsect. Villosae based on it pollen morphology. The current phylogenetic data place the accessions of Trichosanthes subvelutina as sister (1.00/91) to a well-supported clade (1.00/84) consisting of sections Gymnopetalum, Trichosanthes, and Cucumeroides, and the species is here placed in a separate section, sect. Villosae (Yueh & L.Q.Huang) H.J.de Boer.

Pollen

Species with colporate ectoaperturate pollen form two monophyletic groups in Trichosanthes subg. Trichosanthes, one including sections Asterosperma, Pseudovariifera, Foliobracteola, and Truncata, and the other including sect. Villosae, with Trichosanthes subvelutina (data from R. van der Ham 2011, pers. comm.). The latter clade is sister to the clade consisting of sections Trichosanthes, Gymnopetalum and Cucumeroides (1.00/84). The remaining sections in subg. Trichosanthes have porate ectoapertures, and varying exine ornamentation including psilate, (micro-)reticulate, perforate, verrucate, and rugulate pollen (Huang et al. 1997; Pruesapan and Van Der Ham 2005). Gymnopetalum scabrum in sect. Tripodanthera has 3-colporate, rugulate-reticulate pollen (Khunwasi 1998; van der Ham et al. 2010), whereas in Gymnopetalum tubiflorum in sect. Gymnopetalum the pollen is 3-porate and microreticulate (R. van der Ham 2010, pers. comm.).

The other genera in the tribe Sicyoeae have colpate-colporate pollen, similar to that in many other distantly related groups in Curcurbitaceae (Schaefer and Renner 2011). In the light of the molecular data and the phylogenetic analysis (de Boer et al. Submitted), a transition from colporate to porate apertures has taken place three times in the evolutionary history of Trichosanthes, in the common ancestors of: 1) sect. Involucraria; 2) sect. Edulis; and 3) sections Trichosanthes, Gymnopetalum and Cucumeroides.

Taxonomy and classification

A revision of the infrageneric classifications suggested by previous authors on the basis of morphological studies (Yueh and Cheng 1974; Jeffrey 1980b; Huang et al. 1997; Rugayah and de Wilde 1999; de Wilde and Duyfjes 2004) is here proposed on the basis of the molecular phylogenetic data (de Boer et al. Submitted). A synopsis is presented in which we attempt to assign all 91 species recognized here to sections using the clades recovered in the phylogenetic analysis as a framework, along with a plenitude of data from macromorphological studies of herbarium vouchers (Chakravarty 1959; Jeffrey 1980a; Jeffrey 1980b; Jeffrey 1982; Telford 1982; Ohba 1984; Rugayah and de Wilde 1997; Rugayah and de Wilde 1999; Duyfjes and Pruesapan 2004; de Wilde and Duyfjes 2004; de Wilde and Duyfjes 2006; Cooper and Ford 2010; de Wilde and Duyfjes 2010; Lu et al. 2011; Cooper and de Boer 2011) and palynological work (Huang et al. 1997; Pruesapan and Van Der Ham 2005; van der Ham et al. 2010). Synonyms are only included if these are new or relevant for this paper. Names that have been placed in synonymy by previous authors can be found in the above-cited morphological studies.

Trichosanthes L. (1753) Sp. Pl. 2: 1008 – Type: Trichosanthes anguina L. [= Trichosanthes cucumerina L.]

Trichosanthes subg. Scotanthus (Kurz) H.J.de Boer, comb. nov. – Gymnopetalum subg. Scotanthus Kurz (1877) J. Asiat. Soc. Bengal, Pt. 2, Nat. Hist. 46: 99. – Lectotype, designated here: Bryonia cochinchinensis Lour. [ = Trichosanthes costata Blume]

Scotanthus Naud., nom. illeg. (1862) Ann. Sci. Nat., Bot. sér. 4, 16: 172. – Type: Momordica tubiflora Roxb. [ = Trichosanthes costata Blume]

Trichosanthes sect. EdulisRugayah (1999) Reinwardtia 11: 232. – Type: Trichosanthes edulis Ruguyah.

Trichosanthes densiflora Rugayah (1999) Reinwardtia 11: 252

Trichosanthes dentifera Rugayah (1999) Reinwardtia 11: 253

Trichosanthes dieniensis Merr. & L.M.Perry (1949) J. Arnold Arbor. 30: 59

Trichosanthes edulis Rugayah (1999) Reinwardtia 11: 254

Trichosanthes hastata Harms (1925) Bot. Jahrb. Syst. 60: 160

Trichosanthes laeoica C.Y.Cheng & Lu Q.Huang (1996) Bull. Bot. Res., Harbin 16: 503

Trichosanthes odontosperma W.E.Cooper & A.J.Ford (2010) Austrobaileya 8: 126

Trichosanthes pulleana Harms (1925) Bot. Jahrb. Syst. 60: 160

Trichosanthes schlechteri Harms (1925) Bot. Jahrb. Syst. 60: 159

Trichosanthes sect. Involucraria(Ser.) Wight (1840) Madras J. Lit. Sci. 12: 52. – Involucraria Ser. (1825) Mém. Soc. Phys. Genève 3: 27, t. 5. – Type: Involucraria wallichiana Ser. [ = Trichosanthes wallichiana (Ser.) Wight]

Trichosanthes anamalaiensis Bedd. (1864) Madras J. Lit. Sci. III, 1: 47

Trichosanthes borneensis Cogn. (1881) Monogr. Phan. [A.DC. & C.DC.] 3: 369

Trichosanthes bracteata (Lam.) Voigt (1845) Hort. Suburb. Calcutt. 58

Trichosanthes celebica Cogn. (1881) Monogr. Phan. [A.DC. & C.DC.] 3: 385

Trichosanthes cordata Roxb. (1832) Fl. Ind. 3: 703

Trichosanthes coriacea Blume (1826) Bijdr. Fl. Ned. Ind. 15: 935

Trichosanthes dolichosperma Duyfjes & Pruesapan (2004) Thai Forest Bull., Bot. 32: 84

Trichosanthes dunnianaH. Lév. (1911) Repert. Spec. Nov. Regni Veg. 10: 148

Trichosanthes ellipsoidea Merr. (1918) Philipp. J. Sci., C 13: 332

Trichosanthes elmeri Merr. (1929) Univ. Calif. Publ. Bot. 15: 299

Trichosanthes emarginata Rugayah (1999) Reinwardtia 11: 258

Trichosanthes erosaDuyfjes & Pruesapan (2004) Thai Forest Bull., Bot. 32: 85

Trichosanthes fissibracteata C.Y.Wu ex C.Y.Cheng & C.H.Yueh (1974) Acta Phytotax. Sin. 12: 438

Trichosanthes floresana Rugayah (1999) Reinwardtia 11: 260

Trichosanthes globosa Blume (1826) Bijdr. Fl. Ned. Ind. 15: 936

Trichosanthes intermedia W.J.de Wilde & Duyfjes (2004) Sandakania 14: 19

Trichosanthes inthanonensis Duyfjes & Pruesapan (2004) Thai Forest Bull., Bot. 32: 86

Trichosanthes khasiana Kundu (1939) J. Bot. 77: 11

Trichosanthes kinabaluensis Rugayah (2000) Reinwardtia 11: 419

Trichosanthes kostermansii Duyfjes & Pruesapan (2004) Thai Forest Bull., Bot. 32: 89

Trichosanthes laceribractea Hayata (1911) J. Coll. Sci. Imp. Univ. Tokyo 30. Art. 1: 117

Trichosanthes lepiniana (Naud.) Cogn. (1881) Monogr. Phan. [A.DC. & C.DC.] 3: 377

Trichosanthes leuserensis Rugayah (1999) Reinwardtia 11: 265

Trichosanthes longispicata Rugayah (1999) Reinwardtia 11: 266

Trichosanthes montana Rugayah (1998) Reinwardtia 11: 218

Trichosanthes morrisii W.E.Cooper (2011) Austrobaileya 8: 381

Trichosanthes obscura Rugayah (1999) Reinwardtia 11: 269

Trichosanthes pallidaDuyfjes & Pruesapan (2004) Thai Forest Bull., Bot. 32: 90

Trichosanthes papuana F.M.Bailey (1900) Queensland Agric. J. 7: 349

Trichosanthes pedata Merr. & Chun (1934) Sunyatsenia 2: 20

Trichosanthes pentaphylla F.Muell. in Benth. (1867) Fl. Austral. 3: 314

Trichosanthes philippinensis Rugayah (1999) Reinwardtia 11: 271

Trichosanthes planiglans Rugayah (1999) Reinwardtia 11: 273

Trichosanthes pubera Blume (1826) Bijdr. Fl. Ned. Ind. 15: 936

Trichosanthes quinquangulata A. Gray (1854) U.S. Expl. Exped., Phan. 15: 645

Trichosanthes quinquefolia C.Y.Wu ex C.Y.Cheng & C.H.Yueh (1980) Acta Phytotax. Sin. 18: 351

Trichosanthes refracta C.H.Yueh (1996) Bull. Bot. Res., Harbin 10: 500

Trichosanthes rugatisemina C.Y.Cheng & C.H.Yueh (1974) Acta Phytotax. Sin. 12: 440

Trichosanthes sepilokensis Rugayah (1999) Reinwardtia 11: 275

Trichosanthes subrosea C.Y.Cheng & C.H.Yueh (1980) Acta Phytotax. Sin. 18: 349

Trichosanthes tricuspidata Lour. (1790) Fl. Cochinch. 2: 589

Trichosanthes valida Rugayah (1999) Reinwardtia 11: 277

Trichosanthes wallichiana (Ser.) Wight (1840) Madras J. Lit. Sci. 12: 52

Trichosanthes wawrae Cogn. (1881) Monogr. Phan. [A.DC. & C.DC.] 3: 384

Trichosanthes sect. Tripodanthera (M.Roem.) H.J.de Boer, comb. nov. – Tripodanthera M.Roem. (1846) Fam. Nat. Syn. Monogr. 2: 48. – Gymnopetalum sect. Tripodanthera (M.Roem.) Cogn. (1881) Monogr. Phan. [A.DC. & C.DC.] 3: 390. – Type: Bryonia cochinchinensis Lour. [ = Trichosanthes costata Blume]

Trichosanthes costata Blume (1826) Bijdr. Fl. Ned. Ind. 15: 933. — Type: Blume s.n. barcode L0589632, (lectotype L, designated by de Wilde and Duyfjes (2006); 2 isotypes L), Java, Indonesia. Heterotypic synonyms: Evonymus chinensis Lour. (1790) Fl. Cochinch. 1: 156. – Gymnopetalum chinense (Lour.) Merr. (1919) Philipp. J. Sci. 15: 256 – Type: Loureiro †. Bryonia cochinchinensis Lour. (1790) Fl. Cochinch. 1: 595. – Gymnopetalum cochinchinense (Lour.) Kurz (1871) J. Asiat. Soc. Bengal, Pt. 2, Nat. Hist. 40: 57 –Type: Loureiro s.n. (BM), Vietnam. Momordica tubiflora Roxb. (1832) Fl. Ind. 3: 711 – Type: Wallich Cat. 6749 (holotype? K-W), Dacca, Bangladesh. Note: The existence of Trichosanthes chinensis Ser. (1828) Prodr. [A.P. de Candolle] 3: 315 blocks the transfer of Gymnopetalum chinense, based on the basionym Evonymus chinensis, to Trichosanthes. The second name in line of priority would be Gymnopetalum cochinchinensis, based on the basionym Bryonia cochinchinensis. However, the combination Trichosanthes cochinchinensis M.Roem. (1846) Fam. Nat. Syn. Monogr. 2: 96, based on Trichosanthes cucumerina Lour. (1790) 722 (non L.), blocks the transfer. The third name in line of priority is Trichosanthes costata Blume (1826) Bijdr. Fl. Ned. Ind. 15: 933, and this name is available for Gymnopetalum chinense.

Trichosanthes scabra Lour. (1790) Fl. Cochinch. 2: 589. – Gymnopetalum scabrum (Lour.) W.J.de Wilde & Duyfjes (2008) Reinwardtia 12: 268. – Type: Poilane 11322 (neotype P; isoneotype L, designated by de Wilde and Duyfjes (2008)), Annam. Heterotypic synonym: Cucumis integrifolius (‘integrifolia’) Roxb. (1832) Fl. Ind. 3: 724. – Gymnopetalum integrifolium (Roxb.) Kurz (1871) J. Asiat. Soc. Bengal, Pt. 2, Nat. Hist. 40: 58. –Type: Wallich Cat. 6730 (holotype? K-W), Burma.

var. scabra

var. pectinata (W.J.de Wilde & Duyfjes) H.J.de Boer, comb. nov. – Gymnopetalum scabrum (Lour.) W.J.de Wilde & Duyfjes var. pectinatum (W.J. de Wilde & Duyfjes) W.J.de Wilde & Duyfjes (2008) Reinwardtia 12: 268 – Gymnopetalum integrifolium (Roxb.) Kurz var. pectinatum W.J.de Wilde & Duyfjes (2006), Blumea 51: 287. – Type: W.J. de Wilde and Duyfjes 21692 (holotype L), Java, Indonesia.

var. penicaudii (Gagnep.) H.J.de Boer, comb. nov. – Gymnopetalum penicaudii Gagnep. (1918) Bull. Mus. Natl. Hist. Nat. 24: 374. – Gymnopetalum scabrum (Lour.) W.J.de Wilde & Duyfjes var. penicaudii (Gagnep.) W.J.de Wilde & Duyfjes (2008) Reinwardtia 12: 268 – Type: Pénicaud 43 (lectotype P), Hainan, China.

Trichosanthes orientalis (W.J.de Wilde & Duyfjes) H.J.de Boer, comb. nov. – Gymnopetalum orientaleW.J.de Wilde & Duyfjes (2006) Blumea 51: 290. – Type: De Wilde and Duyfjes 21937 (holotype L), Lombok, Indonesia.

Trichosanthes subg. Trichosanthes

Unresolved placement within this subgenus:

Trichosanthes reticulinervis C.Y.Wu ex S.K.Chen (1985) Bull. Bot. Res., Harbin 5(2): 114

Trichosanthes smilacifolia C.Y.Wu ex C.H.Yueh & C.Y.Cheng (1980) Acta Phytotax. Sin. 18: 347

Trichosanthes sect. Asterosperma W.J.de Wilde & Duyfjes (2004) Sandakania 14: 6. – Type: Trichosanthes postarii W.J.de Wilde & Duyfjes.

Trichosanthes auriculata Rugayah (1998) Reinwardtia 11: 216

Trichosanthes fusca W.J.de Wilde & Duyfjes (2004) Sandakania 14: 17

Trichosanthes postarii W.J.de Wilde & Duyfjes (2004) Sandakania 14: 26

Trichosanthes rotundifolia Rugayah (1998) Reinwardtia 11: 223

Trichosanthes sect. Cucumeroides (Gaertn.) Kitam. (1943) J. Jap. Bot. 19: 35. – Cucumeroides Gaertn. (1791) Fruct. Sem. Pl. 2: 485, t. 180, t. 4. – Type: Trichosanthes cucumeroides (Ser.) Maxim. [ = Trichosanthes pilosa Lour.].

Trichosanthes adhaerens W.J.de Wilde & Duyfjes (2004) Sandakania 14: 11

Trichosanthes beccariana Cogn. (1881) Monogr. Phan. [A.DC. & C.DC.] 3: 380

Trichosanthes mucronata Rugayah (1999) Reinwardtia 11: 268

Trichosanthes pendula Rugayah (1998) Reinwardtia 11 (3): 219

Trichosanthes pilosa Lour. (1790) Fl. Cochinch. 2: 588. Heterotypic synonyms according to Cooper and de Boer (2011): Trichosanthes baviensis Gagnep. (1918) Bull. Mus. Natl. Hist. Nat. 24: 379; Trichosanthes trichocarpa C.Y.Wu ex C.Y.Cheng & C.H.Yueh (1980) Acta Phytotax. Sin. 18: 340; Trichosanthes holtzei F.Muell. (1886) Australas. Journ. Pharm. 1: 447.

Trichosanthes siamensis Duyfjes & Pruesapan (2004) Thai Forest Bull., Bot. 32: 97

Trichosanthes tetragonosperma C.Y.Cheng & C.H.Yueh (1974) Acta Phytotax. Sin. 12: 425

Trichosanthes sect. Foliobracteola C.Y.Cheng & C.H.Yueh (1974) Acta Phytotax. Sin. 12: 427. – Type: Trichosanthes kirilowii Maxim.

Trichosanthes homophylla Hayata (1921) Icon. Pl. Formosan. 10: 8

Trichosanthes hylonoma Hand.-Mazz. (1936) Symb. Sin. Pt. 7: 1066

Trichosanthes ishigakiensis E.Walker (1971) J. Jap. Bot. 46: 71

Trichosanthes jinggangshanica C.H.Yueh (1980) Acta Phytotax. Sin. 18: 342

Trichosanthes kirilowii Maxim. (1859) Prim. Fl. Amur. 482

Trichosanthes mianyangensis C.H.Yueh & R.G.Liao (1992) Bull. Bot. Res., Harbin 2: 115

Trichosanthes miyagii Hayata (1921) Icon. Pl. Formosan. 10: 11

Trichosanthes multiloba Miq. (1865) Ann. Mus. Bot. Lugd.-Bat. 2: 82

Trichosanthes rosthornii Harms (1901) Bot. Jahrb. Syst. 29: 603

Trichosanthes sect. Gymnopetalum (Arn.) H.J.de Boer, comb. et stat. nov. – Gymnopetalum Arn. (1840) Madras J. Lit. Sci. 12: 52. –Type: Bryonia tubiflora Wight & Arn. [ = Trichosanthes tubiflora (Wight & Arn.) H.J.de Boer].

Trichosanthes tubiflora (Wight & Arn.) H.J.de Boer, comb. nov. – Bryonia tubiflora Wight & Arn. (1834) Prodr. Fl. Ind. Orient. 1: 347. – Gymnopetalum tubiflorum (Wight & Arn.) Cogn. (1881) Monogr. Phan. [A.DC. & C.DC.] 3: 388 –Type: Rottler s.n. ex Herb. Klein in Herb. Wight Cat. 1118, February 1796 (holotype K; isotypes E, several duplicates), Trincomalee, Ceylon.

Trichosanthes sect. PseudovariiferaH.J.de Boer, sect. nov. Diagnosis: Similar to sect. Foliobracteola, but male flowers with stamens inserted low in receptacle tube, with pseudo-ovary (a thick-walled basal part of the receptacle tube, without staminodes), and fruit with white pulp. Type: Trichosanthes villosa Blume.

Trichosanthes kerrii Craib (1914) Bull. Misc. Inform. Kew: 7

Trichosanthes phonsenae Duyfjes & Pruesapan (2004) Thai Forest Bull., Bot. 32: 9

Trichosanthes sericeifolia C.Y.Cheng & C.H.Yueh (1980) Acta Phytotax. Sin. 18: 346

Trichosanthes villosa Blume (1826) Bijdr. Fl. Ned. Ind. 15: 934

Trichosanthes sect. Trichosanthes

Trichosanthes cucumerina L. (1753) Sp. Pl.: 1008

Trichosanthes dafangensis N.G.Ye & S.J.Li (1989) Acta Phytotax. Sin. 27: 153

Trichosanthes dioica Roxb. (1832) Fl. Ind. 3: 701

Trichosanthes integrifolia Thwaites (1859) Enum. Pl. Zeyl. [Thwaites]: 127

Trichosanthes lobata Roxb. (1832) Fl. Ind. 3: 703. – Heterotypic synonyms: Trichosanthes perrotetiana Cogn. (1881) Monogr. Phan. [A.DC. & C.DC.] 3: 362; Trichosanthes villosula Cogn. (1881) Monogr. Phan. [A.DC. & C.DC.] 3: 342

Trichosanthes nervifolia L. (1753) Sp. Pl.: 1008

Trichosanthes sect. Truncata C.Y.Cheng & C.H.Yueh (1974) Acta Phytotax. Sin. 12: 427. – Type: Trichosanthes truncata C.B.Clarke

Trichosanthes truncata C.B.Clarke (1879) Fl. Brit. India [J.D. Hooker] 2: 608. – Heterotypic synonym: Trichosanthes ovata Cogn. (1881) Monogr. Phan. [A.DC. & C.DC.] 3: 365

Trichosanthes sect. Villosae (Yueh & L.Q.Huang) H.J.de Boer, stat. nov. – Trichosanthes subsect. Villosae Yueh & L.Q.Huang (1997) Act. Phytotax. Sinica 35: 127. – Type: Trichosanthes subvelutina F.Muell. ex Cogn.

Trichosanthes subvelutina F.Muell. ex Cogn. (1881) Monogr. Phan. [A.DC. & C.DC.] 3: 366