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Research Article
Zehneria grandibracteata (Cucurbitaceae), an overlooked new species from western Kenyan forests
expand article infoNeng Wei§, Zhi-Xiang Zhong, David Kimutai Melly§, Solomon Kipkoech§, Benjamin Muema Watuma§, Veronicah Mutele Ngumbau§|, Peris Kamau|, Guang-Wan Hu, Qing-Feng Wang
‡ Chinese Academy of Sciences, Wuhan, China
§ University of Chinese Academy of Sciences, Beijing, China
| National Museums of Kenya, Nairobi, Kenya
Open Access

Abstract

Zehneria grandibracteata, a new species of Cucurbitaceae from western Kenya, is described here, based on morphological and molecular data. It has long been misidentified as the widely-distributed species Z. scabra. However, it differs by its ovate leafy probract at the base of the inflorescences, subglabrous condition of the entire plant, shorter receptacle-tube and filaments, as well as denser and sessile inflorescences. Furthermore, the molecular phylogenetic analysis of Zehneria, based on nrITS sequences, further supports the argument that Z. grandibracteata should be segregated from Z. scabra.

Keywords

East Africa, Flora of Kenya, phylogeny, taxonomy, Zehneria scabra

Introduction

Zehneria Endlicher (1833: 69) is a genus of Cucurbitaceae. It contains over 60 species, which are mainly distributed in tropical and subtropical Africa, Madagascar and south-eastern Asia (Schaefer and Renner 2011a; Dwivedi et al. 2018). Zehneria is characterised by male flowers largely with the three stamens all 2-thecate, the thecae ± erect, straight or little curved (Simmons and De Wilde 2000; Schaefer and Renner 2011a). De Wilde and Duyfjes (2006a, b, 2009a, b) split several genera from Zehneria s.l. (in the sense of Jeffrey), with only the type species, Zehneria baueriana Endlicher (1833: 69) remaining in Zehneria s.s.. Besides, De Wilde and Duyfjes (2006a) proposed morphological characters including leaf drying colour, stamen insertion, presence or absence of staminode, presence or absence of probract and shape of stigmatic lobes, disc and seed, in their circumscription of Zehneria s.s. and the related genera. Nevertheless, this treatment is not supported by the molecular phylogeny inferred by Schaefer et al. (2009), Schaefer and Renner (2011a, b) and Dwivedi et al. (2018), who argued against over-splitting of the group. East Africa has been recognised as a neglected diversity centre for Zehneria (Wei et al. 2017), with several new taxa discovered and named in recent years (Zhou et al. 2016; Wei et al. 2017; Watuma et al. 2019; Ngumbau et al. 2020). Besides, Africa was also referred to as the origin centre (Schaefer et al. 2009; Dwivedi et al. 2018), followed by recent long-distance dispersal to other continents and islands.

During field investigations of the Kenyan flora in 2016, a Zehneria species with evident leafy probracts attracted the authors’ attention for the first time. Herbarium specimens had been identified as Z. scabra Sond. in Harvey and Sonder (1862: 486), a widespread species with great morphological variability. In the following years, more specimens were collected and detailed morphological studies were conducted. Measurements of morphological characters, as well as molecular phylogenetic analysis, based on nrITS, all support the segregation of this Zehneria from Z. scabra. Hence, we describe it as Z. grandibracteata below.

Materials and methods

Morphology

Specimens of East African Zehneria deposited in the herbaria of K, EA and HIB were studied, as well as relevant digitised specimens from online databases, including specimens from the herbaria B, BR, BM, E and P (herbarium acronyms follow Thiers (2020)). Morphological measurements of the details given in the description are based on living materials during the field trips, except tendrils and seeds confirmed by specimen observations at herbaria. The detailed morphological comparison between Z. scabra and our collection was initially made. Given Z. longiflora G.W. Hu & Q.F. Wang in Wei et al. (2017: 89) has largely overlapped the distribution area with our collection, as well as the great similarity with the latter, Z. longiflora was also included for morphological comparison.

Molecular phylogeny

Aiming to delimitate the phylogenetic position of our Zehneria collections, a total of 63 sequences were used to infer a phylogenetic tree. Amongst these sequences, 60 accessions representing 38 Zehneria species were included and another three accessions from Cucumis, Coccinia, Benincasa were treated as outgroups, according to Schaefer et al. (2009) and Dwivedi et al. (2018). Nineteen sequences of African Zehneria species were newly generated in this study, while the other sequences were downloaded from GenBank. The source of the materials and the corresponding GenBank accession numbers were given in Table 1. Total genomic DNA was extracted from silica gel-dried material using a modified CTAB protocol (Doyle and Doyle 1987) (see Suppl. material 1). The primers of nrITS region were obtained from White et al. (1990). PCR amplification, sequencing and data analysis were performed according to Dwivedi et al. (2018). Forward and reverse sequences were manually checked and edited where necessary. Sequences were aligned by MAFFT v. 7 (Katoh and Standley 2013). Gblocks (Talavera and Castresana 2007) was used to trim with the default setting to remove any ambiguous alignment. Additionally, these alignments were visually inspected in Geneious 8.0.2 (Kearse et al. 2012) and manually adjusted where needed. The best-fit model for Bayesian Inference (BI) and Maximum Likelihood (ML) analyses was estimated by ModelFinder (Kalyaanamoorthy et al. 2017) under the Bayesian Information Criterion (BIC). ML analyses were inferred by IQ-TREE v.1.6.8 (Nguyen et al. 2015) under the Ultrafast bootstrapping algorithm (Guindon et al. 2010) with 1000 bootstrap replicates. BI analyses were performed with MrBayes 3.2.7 (Ronquist et al. 2012). Two independent Markov Chain Monte Carlo analyses (MCMC) were run with four simultaneous chains of 10 million generations sampling one tree every 1000 generations with the initial 25% discarded as burn-in. The remaining trees were then used to construct majority-rule consensus trees. The average deviation of split frequencies was verified by reaching a value below 0.01 at the end of MCMC analyses. The effective sample sizes (ESS) for all parameters and statistics were assessed using Tracer version 1.7.1 (Rambaut et al. 2018). The phylogenetic tree was visualised using the online tool iTOL (Letunic and Bork 2007).

Table 1.

GenBank accession numbers for sequence data used in this study.

Species and specimen-voucher Accession No.
Benincasa hispida, Renner et al. 2760 (M) KJ467162
Coccinia grandis, DeWilde & Duyfjes 22270 (L) HQ608207
Cucumis melo, Mitchell & Schaefer 68 (TUM) KY434575
Neoachmandra boholensis, Ramos 2-107/37215 (US) KY523290
Neoachmandra capillacea, Achigan-Dako 07nia757 AM981144
Neoachmandra capillacea, Wieringa 11246 (M) KY523291
Neoachmandra cunninghamii, Telford 12489 (M) KY523292
Neoachmandra filipes, Brass 31994 (US) KY523293
Neoachmandra gilletii, De Wilde 11246 (L) KY523280
Neoachmandra hallii, Achigan-Dako 91sn003 AM981143
Neoachmandra hermaphrodita, Phonsena 440938 (K) KY523281
Neoachmandra japonica, Su EM0045T001 MK771856
Neoachmandra japonica, Zhang 1518 (M) KY523294
Neoachmandra leucocarpa, Junghuhn s.n. (U) KY523295
Neoachmandra odorata, He s.n. (K) KY523307
Neoachmandra odorata, Wallich 6706 (M) KY523297
Neoachmandra pentaphylla, Guillaumin 8611 (US) KY523286
Neoachmandra pentaphylla, McKee 3504 (US) KY523300
Neoachmandra samoensis, Sykes 170278 (L) KY523301
Neoachmandra samoensis, Whistler W2908 (B) MG680626
Neoachmandra thwaitesii, Pallithanam 3637 (BLAT) KY523314
Neoachmandra wallichii, Fujikawa 053262 (TUM) KY523310
Zehneria anomala, Gilbert 1681 (EA) MT733849
Zehneria anomala, Gillett 16503 (M) KY523289
Zehneria baueriana, McKee 38396 (GH) KY523288
Zehneria baueriana, Sykes 533 (US) KY523284
Zehneria bodinieri, Dwivedi 1004 (DUH) KY523266
Zehneria bodinieri, Tanaka 080913 (MBK) KY523267
Zehneria emirnensis, Mitchell & Schaefer 25 (TUM) KY523268
Zehneria grandibracteata, SAJIT 6670 (EA/HIB) MT733851
Zehneria grandibracteata, SAJIT 6966 (EA/HIB) MT733852
Zehneria grandibracteata, SAJIT 6968 (EA/HIB) MT733850
Zehneria guamensis, Perlman 14 (US) KY523273
Zehneria longiflora, SAJIT 6669 (EA/HIB) MT733853
Zehneria longiflora, SAJIT 6672 (EA/HIB) MT733854
Zehneria marlothii, Merxmueller & Giess 30031 (M) KY523283
Zehneria maysorensis, CALI 10625 KY523386
Zehneria maysorensis, Dwivedi 1002 (DUH) KY523256
Zehneria microsperma, Loveridge 64 (GH) KY523274
Zehneria minutiflora, SAJIT 8861 (EA/HIB) MT733855
Zehneria minutiflora, Stolz 1139 (M) KY523296
Zehneria monocarpa, SAJIT 7172 (EA/HIB) MT733856
Zehneria monocarpa, SAJIT 7173 (EA/HIB) MT733857
Zehneria oligosperma, Luke 11710 (EA) MT733858
Zehneria pallidinervia, Holstein 52 (M) KY523287
Zehneria pallidinervia, SAJIT 6241 (EA/HIB) MT733859
Zehneria perpusilla, Santapau 13074 (BLAT) KY523255
Zehneria perrieri, Mitchell & Schaefer 10 (TUM) KY523270
Zehneria pisifera, Hoogland & Pullen 5926 (GH) KY523275
Zehneria polycarpa, Mitchell & Schaefer 36 (TUM) KY523276
Zehneria racemosa, Mendes 1841 (M) KY523298
Zehneria scabra, Schaefer 05/317 HQ202009
Zehneria scabra, SAJIT 6501 (EA/HIB) MT733860
Zehneria scabra, SAJIT 6554 (EA/HIB) MT733861
Zehneria scabra, SAJIT 6736 (EA/HIB) MT733863
Zehneria scabra, SAJIT 6873 (EA/HIB) MT733865
Zehneria scabra, Schaefer s.n. KY523278
Zehneria scrobiculata, Bolus 11558 (M) KY523285
Zehneria scrobiculata, Schimper 164 (M) KY523299
Zehneria tahitensis, Sachet 2662 (US) KY523313
Zehneria tridactyla, Espirito 3053 (M) KY523321
Zehneria tuberifera, SAJIT-6350 (EA/HIB) MT733866
Zehneria tuberifera, SAJIT-W0044 (EA/HIB) MT733867

Results

Morphological comparison

The Table 2 distinguishes morphological characters of these three species, mainly based on Jeffrey (1967, 1978), Wei et al. (2017) and observations on specimens. Our collection can be readily recognisable by its large leafy probract. Besides, it also differs from the other two species by morphological characters including thick stem, subglabrous leaf blade, sessile inflorescence and size of perianth, pedicel, filament, style and fruit.

Table 2.

Dissimilar characters to distinguish Zehneria grandibracteata, Z. longiflora and Z. scabra, based on Jeffrey (1967, 1978), Wei et al. (2017) and own observations.

Character Z. grandibracteata Z. scabra Z. longiflora
Stem Thick, up to 2.5 cm in diam., subglabrous Thick, up to 1.5 cm in diam., puberulous Thin, up to 0.8 cm in diam., subglabrous
Leaf blade Membraneous, deeply cordate to subtruncate at the base, subglabrous, with sparsely scabrid setulose on both sides Membraneous to subcoriaceous, deeply cordate to subtruncate at the base, puberulous on both sides or sparsely scabrid-setulose on the veins beneath Slightly fleshy, membraneous, subglabrous, cordate to subtruncate at the base, with sparsely scattered bristles on adaxial surface only
Male inflorescence Sessile, subumbelliform Subumbelliform or shortly racemiform sessile or pedunculate axillary clusters Sessile or pedunculated, subumbelliform or racemiform
Probract Well-developed, leafy, ovate, up to 18 × 12 mm, incurved, beak-like, persistent Linear, hooked or curly, minute, caduceus Linear, hooked or curly, less than 10 mm long, minute, caduceus
Perianth Receptacle-tube 1.8–3 mm long, hairy only on inner surface, petal lobes ca. 1.8 mm long Receptacle-tube 2.0–5.5 mm long, hairy on both inner and outside surface, petal lobes 1.5–3.5 mm long Receptacle-tube 6.0–7.5 mm long, hairy only on inner surface, petal lobes 2.0–3.0 mm long reflexed
Pedicle 3–12 mm long in male, 4–6 mm long in female 1.5–10 mm long in male, 0.4–11.0 (20.0) mm long in female 4–20 mm long in male, 8–25 mm long in female
Filament length ca. 1.5 mm 1–2.5 mm ca. 3.5 mm
Style length 2–3.5 mm long, stigma ca. 1.5 mm in diam. 2–4 mm long, stigma ca. 2 mm in diam. 6–7 mm long, stigma ca. 2 mm in diam.
Ovary Glabrous, subglobose, with neck up to 1 mm long Puberulous, subglobose to fusiform to beaked, with neck up to 2 mm long Glabrous, subglobose, with neck up to 3.5 mm long
Fruit 2–16 in clusters, sparsely covered with tiny protuberances, subglobose, 8–10 mm in diam. 1–10 in clusters, usually glabrous, globose, 8–13 mm in diameter, or ellipsoid, 10–12 × 7–8 mm 2–8 in clusters, densely covered with tiny protuberances, globose, 9–11 mm in diam.

Phylogenetic analysis

In total, 60 sequences representing 38 Zehneria species were included in our dataset. Multiple sequences per species were identical as to some species, like Z. grandibracteata, Z. anomala, Z. tuberifera and Z. longiflora. They might, however, be different regarding the other species, such as Z. scabra, Z. pallidinervia and Z. minutiflora. The final trimmed alignment of 63 sequences has 721 columns, with 92 parsimony-informative sites. Z. grandibracteata differs in the 71th position (G vs. A) and 208th position (A vs. T) of ITS1 alignment from other Zehneria species. HKY+F+G4 was selected as the best-fit model to infer the Maximum Likelihood tree and Bayesian tree. As shown in Figure 1, three accessions of Z. grandibracteata clustered together with robust support (PP = 0.99; BS = 98%). Then, it joined the other three East African taxa group (Z. oligosperma, Z. tuberifera and Z. longiflora), which offers morphological synapomorphies and a conclusive biogeographic scenario of its evolution. These four species formed a monophyly with high support (PP = 0.99; BS = 96%). However, accessions of Z. scabra did not form a monophyly as expected (newly-sequenced accessions are monophyletic, but two previously-published accessions are nested in Z. monocarpa). Despite the new species being closely related to Z. scabra, they are not recognised as monophyletic in our phylogenetic tree.

Figure 1. 

Bayesian tree inferred from the nrITS sequences dataset to elucidate the phylogenetic position of Zehneria grandibracteata. Bayesian posterior probability values > 0.9 and bootstrap values ≥ 70% are shown below the branches. The new species is highlighted in bold and red colour and Z. scabra is noted in blue colour.

Taxonomic description

Zehneria grandibracteata G.W. Hu, Neng Wei & Q.F. Wang, sp. nov.

Figures 3, 4

Diagnosis

It is close to Z. scabra, but differs by its consistently ovate leafy probracts (linear minute or even absent in Z. scabra), subglabrous condition of the entire plant (puberulous in Z. scabra), shorter receptacle-tube (1.8–3 mm long vs. 2–5.5 mm in Z. scabra) and filaments (ca. 1.5 mm long vs. 1–2.5 mm in Z. scabra), as well as sessile and denser inflorescences (cluster of 8–30 in male, 6–22 in female vs. 2–60 in male, 1–16 in female in Z. scabra) (Table 2).

Type

Kenya. Nandi County, South Nandi Forest, Morongiot area, 0°04'N, 35°00'E, elev. 1980 m, 20 April 2018, Sino-Africa Joint Investigation Team (SAJIT) 006973 (Female) (holotype HIB!; isotype EA!, HIB!)

Description

Perennial climber, 8 m or longer; rhizome robust, woody when old, up to 2.5 cm in diam., roots slender, branched; stem many-branched, grooved, usually contorted when aged, sparsely puberulous except densely hairy at nodes. Leaves simple, petioles 2–7 cm long, grooved adaxially, subglabrous; blades 38–65 × 28–46 mm, ovate-cordate in outline, shallowly 3-lobed occasionally, membraneous, subglabrous, deeply cordate to subtruncate at base, margin slightly sinuate-toothed, apex acuminate and apiculate; scabrid-punctate above, 3–11 main veins sunken adaxially and protrudent abaxially, with sparsely-scattered bristles on both sides, especially on veins and margins; tendrils simple, up to 15 cm long. Dioecious. Inflorescence base with a well-developed leafy probract, up to 18 × 12 mm, ovate, incurved, beak-like, persistent, 2–3 main veins from base, base cordate, apex acuminate. Male inflorescences axillary, sessile, subumbelliform, 8- to 30-flowered, pedicels 3–12 mm long; receptacle-tube 1.8–3 mm long, campanulate, greenish-cream, turning into orange when aged, inner surface densely hairy, outside surface glabrous; sepal lobes 5, ca. 1 mm long, dentiform, pale green; petal lobes 5, ca. 1.8 × 1.5 mm, triangular-ovate, white, turning cream to orange when aged. Stamens 3, inserted in middle of tube; filaments ca. 1.5 mm long, subglabrous, lower half fused with tube; anthers ca.1 mm long, ellipsoid, 2-thecae; thecae 1 mm long, vertical, slightly curved, connective elliptic, with finely papillose hairs; disc ca. 1 mm in diam., depressed globose, obscurely trilobed, elevated. Female inflorescences axillary, sessile, 6- to 22-flowered in umbelliform clusters; pedicel 4–6 mm long; perianth similar to male flowers; ovary subglobose, glabrous, with evident neck up to 1 mm long; style 2–3.5 mm long, glabrous, stigma ca. 1.5 mm in diam., with 3 down-curved papillose lobes; staminodes 3, ca. 1.5 mm long, linear, glabrous, at base of the tube; disc ca. 1.8 mm in diam., annular, 3-lobed, surrounding base of style, free from tube. Fruits clustered, 8–10 mm in diam., subglobose, subglabrous, sparsely covered with tiny protuberances, turning from green to orange when mature; pedicel 5–10 mm long. Seed ovate in outline, narrowly bordered, lenticular, compressed.

Distribution and ecology

Numerous populations of this new species have been documented in the western parts of Kenya’s forests, including Morongiot and Kobujoi areas of South Nandi Forest, Kapsasur area of Nandi Centre, Yale River Trail of Kakamega Forest, Timbilil and Sambret Catchment area of south-western Mau Forest. It usually climbs over tree trunks or twines around shrubs in moist forests or at forest margin at elevations of 1950–2230 m.

Conservation status

This new species was found in the western Kenyan forests with numerous localities. It is locally quite common in the wild and frequently grows in forests or at forest margins. Thus, we assess it to be “Least Concern” (LC) based on IUCN Red List Categories and Criteria (IUCN 2001).

Phenology

Flowering and fruiting from April to July and November to January, corresponding to the wet seasons of the bimodal rainfall pattern of this region.

Etymology

The epithet “grandibracteata” refers to the fairly large leafy probract of this new species.

Additional specimens examined

(Paratypes). Kenya. Nandi County, South Nandi Forest, Kobujoi area, 34°57'E, 0°04'N, elev. 1970 m, 11 December 2016, SAJIT 006670 (EA! HIB!); Nandi County, South Nandi Forest, Morongiot area, 0°04'N, 34°55'E, elev. 1980 m, 19 April 2018, SAJIT 006966 (EA! HIB!) and SAJIT 006968 (EA! HIB!); Nandi County, Nandi Centre, Kapsasur area, elev. 1970 m, 18 April 2018, SAJIT s.n. (HIB!); Kakamega County, Kakamega Forest, Yale River Trail, 0°16'N, 34°52'E, 7 January 2017, SAJIT s.n. (HIB!); Kericho County, Changana Tea Estate, 5.3 miles south of Kericho Town, 0°27'S, 35°18'E, 22 November 1967, Perdue R.E. and Kibuwa S.P. 9179 (BR! EA! K!); Kericho County, Sambret Catchment of southwestern Mau Forest, 0°22'S, 35°23'E, 2160 m, 5 July 1962, Kerfoot O. 3375 (EA! K!); Kericho County, Sambret Catchment of Southwestern Mau Forest, 0°26'S, 35°22'E, 2230 m, 16 Jan 1963, Kerfoot O. 4696 (EA!); Kericho County, Timbilil of southwestern Mau Forest, 0°18'S, 35°31'E, 2130 m, Jan 1963, Kerfoot O. 4708 (EA!).

Discussion

Our Z. grandibracteata collections are recognised as monophyletic, separated from the related Z. scabra. The possible reasons to explain the paraphyly of Z. scabra in our phylogeny are 1) the nrITS provides limited phylogenetically-informative sites in Zehneria and mutations on few loci produced inconsistent phylogenetic topology; 2) the two accessions collected by Schaefer here probably should be Z. monocarpa, which was separated from Z. scabra recently (Ngumbau et al. 2020). Furthermore, we also found that species of Neoachmandra in the sense of De Wilde and Duyfjes (2006a) and De Boer et al. (2015), are paraphyly. In line with the conclusion made by Dwivedi et al. (2018), the whole genus tended to be separated into two major clades (clade 1 and clade 2), with African taxa being the basal lineages. Even though the morphological characters proposed by De Wilde and Duyfjes (2006a) are not suitable for splitting groups (Dwivedi et al. 2018), they are still important and helpful characters when identifying at the species level. The ovate leafy probracts in our new species are readily distinguishable, while probracts on other East African taxa tend to be minute linear hooked or even caducous. Geographically, it is only documented in western Kenyan forests (Figure 2), while Z. scabra is widely distributed in the pantropical Old World region. Furthermore, the molecular phylogenetic analysis of Zehneria, based on nrITS sequences, also supports the segregation of Z. grandibracteata from Z. scabra. Combined with morphological and phylogenetic analyses, Z. grandibracteata is confirmed as new to science.

Figure 2. 

Distribution map of Zehneria grandibracteata in Kenya. Red dots indicate its documented localities.

Figure 3. 

Photographs showing vegetative characters of Zehneria grandibracteata A climbing stem of female plant in habitat B adaxial lamina C creeping stem D abaxial lamina E probracts at different developing stages F tendril and probract at base of female inflorescence. Scale in picture E represents cm.

The broadly circumscribed concept of Zehneria may represent a better natural group, while there is no comprehensive classification system for this group until now. Jeffrey (1962) tried to divide Zehneria into two subgenera, namely subg. Zehneria and subg. Pseudokedrostis (Harms 1923: 616) Jeffrey (1962: 368) (largely accord with clade 1 and clade 2 here), mainly based on the position of stamen insertion, the thecae and connective of anther and length of pedicel. Viewing from the phylogenetic tree inferred by Dwivedi et al. (2018), as well our tree here, Jeffrey’s morphological summaries mostly work well. Besides, the two fruit shapes, short (sub)globose and long fusiform/ellipsoid, largely fit in with clade 1 and clade 2, respectively, though several taxa with round fruits could also be found in clade 2. All these characters would provide insights into building a classification system within the genus Zehneria. Future biogeographical analysis, based on a robust phylogenic framework, would substantially improve our understanding towards its origin and dispersal history.

Figure 4. 

Photographs showing reproductive characters of Zehneria grandibracteata A male inflorescence B male flower, side view C male flower, top view D dissected male flower showing disc and stamens E female inflorescence F female flower, side view G female flower, top view H dissected female flower showing staminodes I pistil and disc J infructescence K cross-section of fruit. Scale bars: 2 mm (B–D, F–I); 1 cm (J, K).

Acknowledgements

We would like to thank the following herbaria BM, BR, EA, HIB, K and P for hosting our visits or providing relevant high-resolution images during our study. Gratitude is also given to the subject editor Norbert Holstein and the reviewer Hanno Schaefer for providing useful comments and suggestions on earlier drafts of the manuscript and to Mrs. Lunlun Gao from Huazhong Agricultural University for preparing the distribution map. Lastly, we are also grateful to the Kenya Forest Service (KFS) for issuing fieldwork permits (permit number: RESEA/1/KFS 98 and RESEA/1/KFS 22) to conduct the field investigations. This work was supported by grants from the National Natural Science Foundation of China (grant number 31970211) and from Sino-Africa Joint Research Center, CAS (SAJC201614).

References

  • De Boer HJ, Cross HB, De Wilde WJJO, Duyfjes BEE, Gravendeel B (2015) Molecular phylogenetic analyses of Cucurbitaceae tribe Benincaseae urge for merging of Pilogyne with Zehneria. Phytotaxa 236(2): 173–183. https://doi.org/10.11646/phytotaxa.236.2.6
  • De Wilde WJJO, Duyfjes BEE (2006a) Redefinition of Zehneria and four new related genera (Cucurbitaceae), with an enumeration of the Australasian and Pacific species. Blumea 51(1): 1–88. https://doi.org/10.3767/000651906X622346
  • De Wilde WJJO, Duyfjes BEE (2009a) Miscellaneous cucurbit news III. Gardens’ Bulletin (Singapore) 61(1): 205–216.
  • De Wilde WJJO, Duyfjes BEE (2009b) Miscellaneous South East Asian cucurbit news II. Reinwardtia 12(5): 405–414.
  • Doyle JJ, Doyle JL (1987) A rapid isolation procedure from small quantities of fresh leaf tissue. Phytochemical Bulletin 19(1): 11–15.
  • Dwivedi MD, Barfield S, Pandey AK, Schaefer H (2018) Phylogeny of Zehneria (Cucurbitaceae) with special focus on Asia. Taxon 67(1): 55–65. https://doi.org/10.12705/671.4
  • Guindon S, Dufayard JF, Lefort V, Anisimova M, Hordijk W, Gascuel O (2010) New algorithms and methods to estimate maximum-likelihood phylogenies: Assessing the performance of PhyML 3.0. Systematic Biology 59(3): 307–321. https://doi.org/10.1093/sysbio/syq010
  • Harms H (1923) Über Melothria pallidinervia Zimmermann. Notizblatt des Botanischen Gartens und Museums zu Berlin-Dahlem 8: 614–616.
  • Harvey WH, Sonder OW (1862) Flora capensis: being a systematic description of the plants of the Cape colony, Caffraria, and Port Natal (and neighbouring territories), Vol. 2. Hodges, Smith, and Co. Dublin, 621 pp. https://doi.org/10.5962/bhl.title.821
  • IUCN (2001) IUCN Red List Categories and Criteria, Version 3.1. IUCN Species Survival Commission, Gland, Switzerland and Cambridge, United Kingdom, 30 pp.
  • Jeffrey C (1962) Notes on Cucurbitaceae, including a proposed new classification of the family. Kew Bulletin 15(3): 337–371. https://doi.org/10.2307/4115586
  • Jeffrey C (1967) Cucurbitaceae. In: Beentje HJ, Ghazanfar SA (Eds) Flora of Tropical East Africa. Royal Botanic Gardens, Kew, Richmond, 156 pp.
  • Jeffrey C (1978) Cucurbitaceae. In: Launert E (Ed.) Flora Zambesiaca. Managing Committee, London, 414–499.
  • Kalyaanamoorthy S, Minh BQ, Wong TKF, von Haeseler A, Jermiin LS (2017) ModelFinder: Fast model selection for accurate phylogenetic estimates. Nature Methods 14(6): 587–589. https://doi.org/10.1038/nmeth.4285
  • Katoh K, Standley DM (2013) MAFFT multiple sequence alignment software version 7: Improvements in performance and usability. Molecular Biology and Evolution 30(4): 772–780. https://doi.org/10.1093/molbev/mst010
  • Kearse M, Moir R, Wilson A, Stones-Havas S, Cheung M, Sturrock S, Buxton S, Cooper A, Markowitz S, Duran C, Thierer T, Ashton B, Meintjes P, Drummond A (2012) Geneious Basic: An integrated and extendable desktop software platform for the organisation and analysis of sequence data. Bioinformatics (Oxford, England) 28(12): 1647–1649. https://doi.org/10.1093/bioinformatics/bts199
  • Ngumbau VM, Nyange M, Wei N, Malombe I, Hu GW, Wang QF (2020) Zehneria monocarpa (Cucurbitaceae), a new species from the relicts of Kenya’s coastal forests. Phytotaxa 443(3): 258–264. https://doi.org/10.11646/phytotaxa.443.3.2
  • Nguyen LT, Schmidt HA, von Haeseler A, Minh BQ (2015) IQ-TREE: A fast and effective stochastic algorithm for estimating maximum-likelihood phylogenies. Molecular Biology and Evolution 32(1): 268–274. https://doi.org/10.1093/molbev/msu300
  • Rambaut A, Drummond AJ, Xie D, Baele G, Suchard MA (2018) Posterior summarisation in Bayesian phylogenetics using Tracer 1.7. Systematic Biology 67(5): 901–904. https://doi.org/10.1093/sysbio/syy032
  • Ronquist F, Teslenko M, van der Mark P, Ayres DL, Darling A, Hohna S, Larget B, Liu L, Suchard MA, Huelsenbeck JP (2012) MrBayes 3.2: Efficient Bayesian phylogenetic inference and model choice across a large model space. Systematic Biology 61(3): 539–542. https://doi.org/10.1093/sysbio/sys029
  • Schaefer H, Renner SS (2011b) Phylogenetic relationships in the order Cucurbitales and a new classification of the gourd family (Cucurbitaceae). Taxon 60(1): 122–138. https://doi.org/10.1002/tax.601011
  • Schaefer H, Heibl C, Renner SS (2009) Gourds afloat: A dated phylogeny reveals an Asian origin of the gourd family (Cucurbitaceae) and numerous overseas dispersal events. Proceedings. Biological Sciences 276(1658): 843–851. https://doi.org/10.1098/rspb.2008.1447
  • Simmons CM, De Wilde WJJO (2000) Zehneria subgenus Zehneria (Cucurbitaceae) in Java and Bali. Blumea 45(1): 235–243.
  • Talavera G, Castresana J (2007) Improvement of phylogenies after removing divergent and ambiguously aligned blocks from protein sequence alignments. Systematic Biology 56(4): 564–577. https://doi.org/10.1080/10635150701472164
  • Thiers B (2020 onwards) Index herbariorum: a global directory of public herbaria and associated staff. New York Botanical Garden’s Virtual Herbarium. http://sweetgum.nybg.org/science/ih/ [accessed 2 May 2020]
  • Watuma BM, Wei N, Melly DK, Kipkoech S, Kirika PM, Hu GW, Wang QF (2019) Zehneria tuberifera (Cucurbitaceae), a new species from Taita Hills, Kenya. Phytotaxa 411(3): 215–222. https://doi.org/10.11646/phytotaxa.411.3.5
  • Wei N, Miyawa DO, David MK, Ngumbau VM, Zhong ZX, Mwachala G, Hu GW, Wang QF (2017) Zehneria longiflora (Cucurbitaceae), a new species from Kenya. Phytotaxa 324(1): 89–94. https://doi.org/10.11646/phytotaxa.324.1.7
  • White TJ, Burns T, Lee S, Taylor J (1990) Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. In: Innis MA, Gelfand DH, Sninsky JJ, White TJ (Eds) PCR Protocols, a Guide to Methods and Applications. Academic, San Diego, 315–322. https://doi.org/10.1016/B978-0-12-372180-8.50042-1

Supplementary material

Supplementary material 1 

Modified CTAB protocol on the base of Doyle and Doyle (1987)

Neng Wei, Zhi-Xiang Zhong, David Kimutai Melly, Solomon Kipkoech, Benjamin Muema Watuma, Veronicah Mutele Ngumbau, Peris Kamau, Guang-Wan Hu, Qing-Feng Wang

Data type: molecular data

This dataset is made available under the Open Database License (http://opendatacommons.org/licenses/odbl/1.0/). The Open Database License (ODbL) is a license agreement intended to allow users to freely share, modify, and use this Dataset while maintaining this same freedom for others, provided that the original source and author(s) are credited.
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