Economic value, endogenous knowledge and distribution of Picralima nitida (Stapf) T. Durand and H. Durand in Africa [version 1; peer review: 2 not approved]

Background: Picralima nitida (Apocynaceae) is an important African medicinal plant species. It is frequently used in traditional medicine and pharmaceutical industries for manufacture of drugs against infectious diseases, malaria, diabetes and cancer. Despite its important, the species can be rare, especially in the Dahomey Gap (in contrast to the Guineo-Congolese region). There is also a controversy on its distribution. To ensure the sustainable use of the species, this study evaluated the economic value, endogenous knowledge and effect of climate gradient on the distribution of the species in Africa. Methods: Ethnobotanical surveys were conducted in the Dahomey Gap with 120 informants randomly interviewed. A literature review of scientific papers and books was used to provide information on the uses, distribution and threats of the species in the Guineo-Congolese region. Results: The results revealed that P. nitida products were more expensive in the Dahomey Gap than the Guineo-Congolese region. All parts of the species were collected and used for 34 treatments. The species had low density and distribution in Dahomey Gap compared to the Guineo-Congolese region. Conclusions: P. nitida is used across its distribution areas with important economic values. Adapted management strategies are needed for the sustainable use and conservation of the species.


Introduction
Picralima nitida is one of the most important medicinal plant species in Africa (Bickii et al., 2007). It is a small tree which reaches 4-35 m in height. Its wood is pale yellow, hard, elastic and fine-grained with a high polish. P. nitida bears white flowers (about 3 cm long) with yellowish ovoid fruits at maturity. The leaves are broad and oblong with tough tiny lateral nerves of 14-24 pairs. In West African folk medicine, P. nitida is widely used for the treatment of several diseases. The species is known as a febrifuge and a cure for infectious disease, malaria, diabetes and pain (Aguwa et al., 2001;Akabassi et al., 2017;Betti et al., 2013;Teugwa et al., 2013). In addition to its medicinal uses, P. nitida provides an income to millions of households in Africa. In Cameroun, P. nitida contributes to more than 12% of household income of Nguila and Mbangassina villages (Yakeu, 2012).
Despite its importance, there is a serious problem of species management. In the typical Guineo-Congolese (GC) region, e.g. Nigeria, it occurs only in the wild under no form of management and is under threat of extinction (Gbadamosi, 2014). In the Dahomey Gap (DG) region, e.g. Benin, P. nitida is very rare and at low density (Akabassi et al., 2018). There is a controversy on the exact distribution areas of P. nitida. Adjanohoun et al. (1996) report that the range of P. nitida extends from Côte d'Ivoire to Uganda and South Africa to the Democratic Republic of Congo and Cabinda region in Angola with a gap in Togo (Figure 1). Eyog Matig et al. (2006) report that P. nitida is a tropical African species distributed in Ghana, Côte d'Ivoire, Nigeria, Angola, the Democratic Republic of Congo, Cameroon and Tanzania. Once more, Togo is not mentioned as a distribution area of the species. Omino (1996) reported that the distribution area of P. nitida does not cover the DG. However, Holaly et al. (2015) reported the presence and use of P. nitida in the Maritime region of Togo. The inventory of the news angiosperm species in the flora of Togo revealed that P. nitida is found in the ecological district IV of the country (Akpagana et al., 1994).
There is a need to dispel the ambiguity over the distribution areas of this species and to document the important threats to its conservation. This study assesses (1) the economic value and endogenous knowledge of P. nitida in Africa and (2) the effect of climate gradient on the species distribution.

Study areas
The study areas were typical GC regions (Cameroon, Central African Republic, Congo Brazzaville, Côte d'Ivoire, Democratic Republic of Congo, Gabon, Ghana, Nigeria and Uganda) characterized by rainforests with a rainfall of up to 2500 mm, and the DG region (Benin and Togo) characterized by savannas that extend down to the coast with a mosaic of rainforest ( Figure 2). The DG is the dry zone that separates the two blocks of forest in tropical Africa (Bongers et al., 2004). The overall annual rainfall varies between 900-1400 mm.
Economic value and endogenous knowledge of P. nitida in Africa Sampling. A preliminary survey was conducted in DG on the use of the species. The sample size was determined following the formula of Dagnelie (1998).   Figure 2 has been reproduced with permission of [Church, 1966].
is the value of the normal random variable at probability value of α= 0.05 and d is the margin error of the estimation of any parameter to be computed from the survey. A value of 8% was considered.

Data collection
Individual interviews were conducted in Togo and Benin with a total of 120 key informants. The main local languages interviewed were Fon, Goun, Nago, Yorouba, Adja in Benin and Mina, Ewe, Kotafon in Togo. The survey has been piloted prior to its use. In Benin, the survey covered two phytodistricts (Pobè and Vallée de l'Ouémé where the species is only presented (Akoègninou et al., 2006) and 30 informants were selected in each phytodistricts. In Togo, the survey covered Danyi located in ecological district IV (only presence area of the species (Akpagana et al., 1994) and 60 informants were selected. The survey was performed between January and July 2018 and conducted in the local language using a questionnaire (see Extended data) (Akabassi, 2020c) (Akabassi, 2020d). The survey was carried out through the households using a local guide. The local guide approached households in person and participants aged 18 and over were considered regardless of education and gender. Most informants were selected from localities with at least one P. nitida individual. These localities were Ifangni, Sakété, Adja-Wèrè, Ikpinlè, Kétou, Avrankou, Adjarra, in Benin and Kouma, Danyi, Akposso-Akébou, Kpalimé-Atakpamé in Togo. Data were collected on the economic and socio-cultural values of the species, the uses and organs used, the frequency of use and main threats of the species.

Literature search
In the typical GC region, data were collected through a literature search. The original articles obtained from various databases including Google Scholar, Web of Science, Scopus, PubMed Central and JSTOR in addition to reports, thesis and Biodiversity databases (www.prota.org and www.gbif.org) were used to gather information on the importance of the species. The main research theme used were: "Economic value" AND "Picralima nitida"; "Endogenous knowledge" AND "Picralima nitida"; "Distribution" AND "Picralima nitida"; "Togo" AND "Picralima nitida"; "Benin" AND "Picralima nitida". A total of 31 published articles between 1996 and November 2018 were selected based on their importance for the topic. All articles not dealing with ethnobotanical importance and distribution of P. nitida were excluded. The data that were extracted from selected articles were the different uses of P. nitida organs, mode of preparation, dosage and GPS coordinates of the individuals of the species.

Ethics and consent
The study received ethical approval from community leaders of the DG and ensured informed consent was received for data collection and analysis. Three key ethical issues considered were: voluntary participation; anonymity and confidentiality of data analysis were ensured. Furthermore, before starting the questionnaire the participants were openly told of the purpose of the study and consent was sought verbally. Verbal consent was sought as the most of participants were unable to read or write.

Data analysis
The importance of P. nitida for the surveyed populations was determined by the calculation of the use frequency of the plant properties (FUP).

FUP Rv Rah Raf
Ne is the total number of interviewees; Rv, Rah and Raf are the number of old, adult and young interviewees that used the property, respectively. A property was considered as 'credible' in case FUP is above 50% (Assogbadjo et al., 2011a;Camou-Guerrero et al., 2008).
The most used plant organ was identified through the computation of the index value related to useful organs (IVO).

100;
Nvo, the number of properties in the organ; Ne, the total number of identified properties.
Further, based on the literature review and the above analysis, absolute global credibility (AGC) for each use was calculated using the following formula: With N pu the distribution areas of the use X, N tp the total distribution area of the species. A usage is considered absolute if AGC ≥ 50%. The countries (Uganda and Central African Republic) where no information was obtained on the use value of the species were not taken into account.
Basing on the collected data, the uses of the species were grouped into three fields of traditional application, namely: medicine, medico-magic and culture. A use was considered medicinal when results from the use of one part of the species associated or not with other plants or ingredients of animal without any ritual, prayers or incantations. A use was considered medico-magic when it associates the medicinal use with ritual, prayers or incantations. A use was considered cultural when practices during ritual ceremonies, funeral ceremonies, weddings, sacrificial rites and handicraft.
Effect of climate gradient on the species density and distribution Data collection and analysis. In DG, the samples of P. nitida were collected during the ethnobotanical survey carried out between January and July 2018 in Benin and Togo in order to study the distribution and the density of the species. The zones of presence of the species in Benin (phytogeographical districts of "Pobè and Vallée de Ouémé") and Togo (ecological subdivision IV of Togo) were explored. The presence of P. nitida was obtained through a field exploration in collaboration with local population. The collaboration was largely done with the medicinal plant dealers to identify the presence of the species. The georeferenced coordinates were recorded for each sample of P. nitida identified. A total area of 4590.52 km² was explored in Benin, while 115.765 km² was explored in Togo, in the typical GC region, data on the species density and distribution were collected using a literature review. The species occurrence coordinates were gathered from the GBIF website and were used to create a distribution map of the species.

Results and discussion
Economic value and endogenous knowledge of P. nitida in Africa Economic value of P. nitida. The survey conducted in the DG revealed that the largest fruit of P. nitida (about 1000 g) cost US$1 per unit, the average (about 700 g) US$0.80 and the smallest (about 300 g) US$0.5. One seed costed US$ 0.05. A kilogram of P. nitida seeds cost between US$6 and US$10.
In the GC region, e.g. Ghana, P. nitida seeds were dried, powdered, encapsulated and sold as "Picap capsules" that cost between US$12.99 and US$225 depending on the quantity (https://thegradekratom.com/product/akuamma-seeds/). In Cameroon, seeds, bark and fruit were sold (US$5 for 550 g of seeds or bark) in local markets (Betti, 2002;Betti, 2004). In Congo, 800 g of fruit cost about US$1 (http://database.prota.org/ PROTAhtml/Picralima%20nitida_En.htm). This indicated how the species can contribute to household income. P nitida products were more expensive in the DG. P. nitida is very rare in this region and this probably justifies the high prices observed in the DG. The species was mainly found in home gardens and/or house yards in the DG. The domestication of non-timber forest species like P. nitida is an opportunity to alleviate poverty with positive benefits on the environment, since new plantations of P. nitida will contribute to reduce the greenhouse gas emission. It is therefore important to develop a management program for the sustainable use of the species. This can offer more jobs and help in poverty alleviation in countries such as Cameroon where the species contributes to 12% of household income (Yakeu, 2012).
Endogenous knowledge of P. nitida. In the DG, 24 uses of the organs of P. nitida including roots, bark, leaves and seeds were cited (Table 1). A total of seven uses were credible (infectious diseases, angina, malaria, bellyaches, rituals, analgesic and diabetes). The overall credibility of the uses was 75.94% in Benin and 70.94% in Togo. This indicated that P. nitida is very important in the the DG. The seed was the most important  organ used in the DG (79.16% in Benin and 83.33% in Togo). The credible uses were the same in both countries. The similarity between these two countries of the DG in the use of the organs of P. nitida may be related to the close crossborder exchanges between these two countries that share some ethnic groups, cultures and ancestral traditions native from the Tado kingdom, located in Dahomey (Kossi, 1990). For instance, Mina, Fon and Ewe are ethnic groups shared between the two countries which favor knowledge dissemination.
In the GC region, 24 uses of the organs of P. nitida, including the roots, bark, leaves, seeds, fruits and wood, were cited (Table 2). A total of four uses were credible (diabetes, malaria, fever and sexual weakness). The overall credibility of the plant uses in the GC region was 60.85, indicating that P. nitida was important in this region. The seed was the most important organ used in the Guineo-Congolese region followed by the wood, fruit, leaves, bark and root (Table 2).
In the DG and GC regions, P. nitida was most frequently used against malaria, followed by measles, diabetes, worms, sexual weakness, hernia, fevers, infectious diseases and diarrhoea, as well as for shovel handles and spoons (Table 3). Shovel handles and spoons were a specific use in the GC region. Among these diseases, malaria is a principal cause of mortality and poverty in Africa (WHO, 2011). The use of the organs of P. nitida to treat these diseases will contribute to reduce mortality and poverty in Africa.
Knowledge of the species in the DG was significantly greater than that in the GC region ( Figure 3). This difference may be explained by the low density of the species in the DG, which forces the users to give more attention to the species. Some uses were specific to certain regions with good credibility as the case of the use of the seeds to treat tonsillitis in the DG. The different uses of the species mentioned in this paper could help local communities to benefit from the medicinal values of the species. Moreover, the fact that some uses were specific to each climate zone will be relevant when defining for each zone a valorization program of the species.
In both climate zones (DG and GC regions), among the uses identified, 26 were of medicinal, three in medico-magic and three cultural (Table 4).
In the DG, each the three fields were used, whereas in the GC region, P. nitida was not considered for medico-magic use. This confirms the stronger level of knowledge on the species in the DG. The cultural differences and specific local population needs between the two climates zones may also explain this variation in use (Dadjo et al., 2012).
Effect of climate gradient on the density and distribution of P. nitida Distribution and density of P. nitida in the DG. During the investigation in Togo, P. nitida was found in the southwest   of the country, 185 km from Lomé at 800 m altitude in "Danyi Dzogbégan" region at monastery "Abbaye de l'Ascension". This region is situated in ecological district IV, corresponding to dense semi-deciduous forests. P. nitida was not found in natural vegetation. The distribution map of the species elaborated by Adjanohoun et al. (1996) did not include Togo. This may be due to the lack of information available on the species in 1996 or the absence of the species in natural habitats. Moreover, the individual of the species observed in the monastery may be introduced after 1996.
In Benin, P. nitida was found in forest in the phytogeographic zones of "Pobè and Vallée de l'Ouémé" located in the southeast of the country and characterized by the GC climate condition. The occurrence of the species decreases either in latitude from the south or in longitude from the southeast. In addition to forests, P. nitida was found in home gardens and home yards in the DG.
The species is almost absent in the dry forests of the DG (Figure 4). P. nitida was found at very low density in the DG (0.020 ind./km 2 and 1.75 ind./village in Togo and 0.022ind./km 2 and 1.87 ind./village in Benin). The DG is not a suitable habitat of the species because of the dry climate in this region. The occurrence of the species in this region may be the results of long domestication process due to the importance of the species to the local populations. This may explain why some authors (Eyog et al., 2006;Omino, 1996) do not consider the DG to be a distribution area of P. nitida.

Distribution of P. nitida in Guineo-Congolese region.
In all the countries of the Guineo-Congolese region (Cameroon, Central African Republic, Congo Brazzaville, Côte d'Ivoire, Democratic Republic of Congo, Gabon, Ghana, Nigeria and Uganda), P. nitida was found in forests. In Cameroon, P. nitida occurred in forests (52%) and farms (30%) (Yakeu, 2012). The occurrence point of P. nitida can be qualified in two ways ( Figure 4). In the Upper Guinea (from Guinea and Sierra Leone to Ghana" Western Region"), the occurrence of P. nitida was average. In Lower Guinea (Nigeria and eastward; "West Central Region"), P. nitida had many occurrences that may be justified by the highest rainfall observed in this area, especially in western Cameroon, which experiences 3,000 mm of precipitation per year (Lefèvre, 1967).
Individual-level responses to the ethnobotanical survey and geographical distribution locations are available as Underlying data (Akabassi, 2020a) (Akabassi, 2020b)

Conclusion
The organs of P. nitida (seed, bark and fruit) are sold in the DG and GC region and contribute in households' income. The species has a total of 24 uses in medicine, medico-magic and culture in Dahomey gap and GC region with more credible uses and knowledge in the DG. P. nitida is rarer in the DG than in GC region. Adapted management strategies are needed for the sustainable use and conservation of the species in the two climatic zones. The paper deals with the importance of Picralima nitida (Stapf) T. Durand and H. Durand, known as an important African medicinal plant species in Dahomey Gap region in general and in Togo in particular, especially at the glance of its: i) economic value, ii) endogenous knowledge and distribution. However, the paper failed to take into consideration several aspects such as i) poor knowledge about the exact distribution of the Picralima nitida plant species, ii) the issue of erosion of local knowledge and the need for its safeguard; iii) the causes of plant species (Picralima nitida) rarity, and iv) any available initiatives/interventions that have been carried out to address the issue along with any available policy and available regulations in place to guide sustainable management of biodiversity in general and Picralima nitida medicinal plant species in particular. Undermining such background knowledge has contributed to lowering the quality and strength of the paper. As a result, in its current stage, the paper could not be accepted for indexing, unless important ameliorations are made.

Data availability
Please see my detailed comments in the PDF file found here.

Are sufficient details of methods and analysis provided to allow replication by others? Partly
If applicable, is the statistical analysis and its interpretation appropriate? Not applicable

Introduction:
Remove: It is a small tree which reaches 4-35 m in height. Its wood is pale yellow, hard, elastic and fine-grained with a high polish. P. nitida bears white flowers (about 3 cm long) with yellowish ovoid fruits at maturity. The leaves are broad and oblong with tough tiny lateral nerves of 14-24 pairs. This section is out-of-place.
○ "In addition to its medicinal uses, P. nitida provides an income to millions of households in Africa." How so? Explain via an additional sentence.
○ "The species is known as a febrifuge and a cure for infectious disease, malaria, diabetes and pain (Aguwa et al., 2001;Akabassi et al., 2017;Betti et al., 2013;Teugwa et al., 2013)". -The issue of string citation (listing multiple authors at end of sentence) is a pervasive problem in this manuscript. By placing multiple consulted sources at the end of a sentence implies all information in that sentence can be attributed to those authors -thus per implication they (authors) stated exactly the same information -in which case why cite more than one, when the most authoritative would suffice? This issue must be corrected by placing sources immediately after used fact inside the sentence, when dealing with multiple authors in a sentence, so as to explicitly attribute a specific fact to a specific source. Correct throughout the manuscript. ○ Figure 1: does not show the full distribution range of the species, especially in southern Africa.
○ "There is a need to dispel the ambiguity over the distribution areas of this species and to document the important threats to its conservation." Where is the threat analysis and discussion?

Materials and Methods
Study area: "The study areas were typical GC regions (Cameroon, Central African Republic, Congo Brazzaville, Côte d'Ivoire, Democratic Republic of Congo, Gabon, Ghana, Nigeria and Uganda" -incorrect. The study area was confined to DG countries, Togo and Beninrephrase. ○ Figure 2: "…characterized by rainforests with a rainfall of up to 2500 mm, and the DG region (Benin and Togo) characterized by savannas that extend down to the coast with a mosaic of rainforest (Figure 2)." Figure 2 does not show mosaic of rainforests or savannas.
○ ○ Economic value and endogenous knowledge: "A preliminary survey was conducted in DG on the use of the species." Indicate (1) reasons for preliminary survey, (2) how many people surveyed and how. Effect of climate gradient on species density and distribution: "…in the typical GC region, data on the species density and distribution were collected using a literature review. This is extremely strange (and unlikely) that density of individual plants is presented in the literature. How old are the sources consulted? Still valid/relevant for period of this study? How complete was the information gathered via literature review? How was literature review done? Relook this.

○ ○
Results/Discussion ○ Economic value: "P. nitida seeds were dried, powdered, encapsulated and sold as "Picap capsules" that cost between US$12.99 and US$225 depending on the quantity…" -For which region/country is this? How old is this information? How scientifically correct is the information that is derived from a non-peer-reviewed web-based source. ○ (https://thegradekratom.com/product/akuamma-seeds/). -web addresses not to be included in text -relocate to reference section. ○ "P. nitida products were more expensive in the DG." -more than?
○ "The domestication of non-timber forest species like P. nitida is an opportunity to alleviate poverty with positive benefits on the environment, since new plantations of P. nitida will contribute to reduce the greenhouse gas emission."-this is such a general statement as to apply to any plant species -relook. ○ "It is therefore important to develop a management program for the sustainable use of the ○ species." On the contrary, no information has been provided to indicate unsustainable use or harvesting. So why is a management program necessary? Because it is rare? But could be due to abiotic factors such as climate and soil, not necessary due to adverse anthropogenic actions. Relook.
Endogenous knowledge: Bark -is this stem bark or root bark? ○ Bellyaches -replace with stomach aches.
○ "This indicated that P. nitida is very important in the the DG." -this is a prime example of some of the many unprofessional editorial issues abound in this paper.
○ Table 1 and ○ "The seed was the most important organ used in the Guineo-Congolese region followed by the wood, fruit, leaves, bark and root (Table 2)." -Why and what would be the conservation impact/population sustainability impact? Discussion needed.
○ "In the DG and GC regions, P. nitida was most frequently used against malaria, followed by measles, diabetes, worms, sexual weakness, hernia, fevers, infectious diseases and diarrhoea, …" Are there any biochemical/microbiology papers found that scientifically validate these claims? Discussion needed.
○ "… uses were specific to certain regions with good credibility as the case of the use of the seeds to treat tonsillitis in the DG." Is there any biochemical/microbiology papers found that scientifically validate these claims? Discussion needed. In Lower Guinea (Nigeria and eastward; "West Central Region"), P. nitida had many occurrences …"-What constitutes many occurrences? Occurrence categories not presented in Materials and Methods section.
○ "… in western Cameroon, which experiences 3000 mm of precipitation per year (Lefèvre, 1967). This rainfall of 3000 mm per annum comes from 53 ago (1967). Rainfall data not reflective for the study period of this paper. Climate change in the last 50 odd years has significantly altered the numbers. Use more up-to-date sources and data.

If applicable, is the statistical analysis and its interpretation appropriate? Partly
Are all the source data underlying the results available to ensure full reproducibility? Partly Are the conclusions drawn adequately supported by the results? Partly addressed.

Title:
R: The title indicates: "Economic value, endogenous knowledge and distribution of Picralima nitida (Stapf) T. Durand and H. Durand in Africa" -However, this study was only confined to DG, Togo and Benin. Thus, vast areas of the distribution range of P. nitida are excluded from this study (e.g. South Africa). This implies that the title needs to be reformulated to indicate the localities of DG, Benin and Togo.
A: This study involves in addition to DG (Benin and Togo) the Guineo-Congolese region which include the Upper Guinea (from Guinea and Sierra Leone to Ghana" Western Region") and the Lower Guinea (Nigeria and eastward; "West Central Region")). Picralima nitida is native from the Guineo-Congolese region. According to Bongers et al. 2004, Poorter et al. 2004, Church, 1966, and White, 1983, the Guineo-Congolese region does not include South Africa. Moreover, there is no occurrence of the species in South Africa on GBIF database. I will be very pleased if you could update the occurrence of the species on GBIF with the reference points in South Africa. This will help to improve the distribution map of the species.
Abstract R: Methods: threats not captured in title, no result presented on it -remove? A: The threats on the species were addressed based on the overexploitation of its organs. The section on Endogenous knowledge of P. nitida in the results provides information on the exploitation of the organs of the species. The seed was the most important organ used in the Guineo-Congolese region followed by the wood, fruit, leaves, bark and root"; "The seed was the most important organ used in the DG (79.16% in Benin and 83.33% in Togo)". The overexploitation of the seeds, bark and root (vital organ of the plant) are an important threat on the conservation of the species. Other threat of the species in the article is the climate gradient. The species is scarce in DG compared to Guineo-Congolese region.

Introduction:
R: Figure 1: does not show the full distribution range of the species, especially in southern Africa.
A: This figure is provided by Adjanohoun et al. (1996). If the species is also present in South Africa, it will be good to update the occurrence of the species that will contribute to update the figure in future publication R: "There is a need to dispel the ambiguity over the distribution areas of this species and to document the important threats to its conservation." Where is the threat analysis and discussion? A: In this study the threats were mainly assessed in relation to the importance of the species for the local populations. The use of the various organs (especially the seeds) of the species without any form of sustainable management constitutes a threat to the sustainability of the species. In addition, the second part of this study dealing with threats to the species is its frequency according to the climate gradient. In this study, we found that in both DG countries. For instance, in Benin the occurrence of the species decreases either in latitude from the south or in longitude from the southeast. Its presence is reduced to a few isolated individuals found in home gardens. In the Guineo-congolese zone the density of the species is high in the zones with high rainfall such as the Democratic Republic of Congo, Cameroon (Please consult GBIF website). These different results showed the effect of climate gradient on the distribution of P. nitida.

Materials and Methods
R: Figure 2: "…characterized by rainforests with a rainfall of up to 2500 mm, and the DG region (Benin and Togo) characterized by savannas that extend down to the coast with a mosaic of rainforest ( Figure 2)." Figure 2 does not show mosaic of rainforests or savannas. A: Figure 2 showed the DG and Guineo-Congolese regions. In the figure, the Guinean-Congolese part has been marked green. The two green parts have been separated by the Dahomey Gap. According to literature (Adomou, 2005, Akoegninou et al., 2006, Church, 1966 the Guineo-Congolese region is forest area characterized by rainforests with a rainfall of up to 2500 mm, and the DG region (Benin and Togo) characterized by savannas that extend down to the coast with a mosaic of rainforest.
Economic value and endogenous knowledge: R: "A preliminary survey was conducted in DG on the use of the species." Indicate (1) reasons for preliminary survey, (2) how many people surveyed and how. A: A preliminary survey was conducted in DG on the use of the species to calculate the sample size to be used in the full study, according to the formula of Dagnelie (1998).

Data collection:
R: Indicate how key informants were selected, Gender and age? Indicate how households were selected. A: Please see this section of methodology "The survey was carried out through the households using a local guide. The local guide approached households in person and participants aged 18 and over were considered regardless of education and gender. Most informants were selected from localities with at least one P. nitida individual. Data were collected on the economic and socio-cultural values of the species, the uses and organs used, the frequency of use and main threats of the species.

Ethics and consent:
R: Individuals involved in the study can only give consent, not ethical approval. Ethical approval was sought and given by which university? Indicate ethical clearance certificate number. A: Ethical approval was not sought for this study. The study is deemed by the researchers to be low risk, as it did not record any identifying information of participants; was not an interventional-or clinical-based study. However, a consent has been received from community leaders and participants of the DG and ensured informed consent was received for data collection and analysis.