diversity Review Recovering Plant Data for Guinea-Bissau: Implications for Biodiversity Knowledge of West Africa Maria M. Romeiras 1,2,* , Maria Cristina Duarte 2 , Javier Francisco-Ortega 3,4, Luís Catarino 2 and Philip Havik 5 1 Linking Landscape, Environment, Agriculture and Food (LEAF), Instituto Superior de Agronomia, Universidade de Lisboa, 1349-017 Lisbon, Portugal 2 Centre for Ecology, Evolution and Environmental Changes (cE3c), Faculdade de Ciências, Universidade de Lisboa, 1749-016 Lisbon, Portugal; [email protected] (M.C.D.); [email protected] (L.C.) 3 International Center for Tropical Botany, Department of Biological Sciences, Florida International University, Miami, FL 33199, USA; ortegaj@fiu.edu 4 Kushlan Tropical Science Institute, Fairchild Tropical Botanic Garden, Coral Gables, FL 33156, USA 5 Centre for Global Health and Tropical Medicine, Instituto de Higiene e Medicina Tropical, Universidade NOVA de Lisboa, 1349-006 Lisbon, Portugal; [email protected] * Correspondence: [email protected]; Tel.: +351-21-365-3100 Received: 10 September 2018; Accepted: 1 October 2018; Published: 6 October 2018 Abstract: The rich plant diversity that characterizes the West African Region and the inherent knowledge of their flora and vegetation has been the backbone of scientific explorations during the past centuries. The evolution of botanical knowledge on Guinea-Bissau, throughout the 16th and 20th centuries is reviewed. We present and discuss floristic data collected by scientific expeditions between the mid-1700s to 1974, when the Portuguese colonial period ended. Expeditions undertaken by French naturalists provided some of the earliest plant collections. A list of herbarium specimens collected by the French naturalist Jardin, in the Bijagós Islands in ca. 1847–1858 is presented here for the first time, while in the late 1800s some Portuguese naturalists also explored Guinea-Bissau. During the colonial period (1915–1974), Gomes e Sousa published the first comprehensive study of the territory’s flora while Espírito Santo assembled the largest plant collection. Our review applies a multi-disciplinary perspective to fill important lacuna regarding biodiversity knowledge of this under-researched West African country. It constitutes the first study tracing the long term evolution of knowledge on Guinea Bissau's plant diversity, which provides the basis for understanding trends and research priorities, in particular in conservation and botanical fields. Keywords: plant diversity; botanical history; West Africa; scientific collections; naturalists; African Flora 1. Introduction The West African country of Guinea-Bissau shares common frontiers with Senegal and the Republic of Guinea, while bordering the Atlantic Ocean (Figure1A). It is characterized by low-lying littoral areas of mangroves, gradually shifting in an easterly direction to a transitional zone covered with palm forests and woodland (Figure1B), extending to a slightly elevated savannah plain and the outliers of the Futa Djallon Massif (Republic of Guinea), sloping upwards to a maximum elevation of 300 m [1]. The Bijagós Islands off the coast, covered with mangroves, palm groves and dry forested areas (Figure1C), form a continuation of the coastal plateau which is dissected by a number of rivers such as the Cacheu, Mansoa, Geba and Corubal, and the Rio Grande de Buba (Figure1A). Diversity 2018, 10, 109; doi:10.3390/d10040109 www.mdpi.com/journal/diversity Diversity 2018, 10, 109 2 of 14 Diversity 2018, 10, x 2 of 14 Guinea-Bissau’s vascular flora flora comprises ca. 1507 species, of which 1459 are native. The native vascular plantsplants areare classifiedclassified into into 157 157 plant plant families families and and 697 697 genera, genera, namely: namely: 22 22 species species belonging belonging to 14to families14 families are Pteridophyteare Pteridophytesensu sensu lato; andlato; amongand among the angiosperms: the angiosperms: 396 species 396 species belonging belonging to 33 families to 33 arefamilies Monocots; are Monocots; and 1041 and species, 1041 belongingspecies, belonging to 107 families to 107 arefamilies Eudicots are Eudicots [2]. Despite [2]. theDespite great the number great ofnumber plant of species plant nativespecies to native Guinea-Bissau, to Guinea-Bissau, the uniformity the uniformity of ecological of ecological conditions conditions and the and size the of size the territoryof the territory have not have favored not favored endemic endemic species, andspecies, only andPandanus only Pandanus guineabissauensis guineabissauensisHuynh and HuynhAmmannia and santoiAmmannia(A. Fern. santoi & (A. Diniz) Fern. S.A. & GrahamDiniz) S.A. & Gandhi Graham are & in-country Gandhi are endemic. in-country This endemic. country boastsThis country a great culturalboasts a diversitygreat cultural that hasdiversity resulted that in has significant resulted ethnobotanical in significant ethnobotanical traditions [3]. traditions [3]. Figure 1.1. ((AA)) WestWest Africa Africa with with details details of of the the modern-day modern-day boundaries boundaries of Guinea-Bissau, of Guinea-Bissau, which which were were only establishedonly established in 1886, in following1886, following the treaty the betweentreaty between France andFrance Portugal. and Portugal. Localities Localities indicated indicated on the map on werethe map the were focus the of focus the first of the botanical first botanical expeditions, expeditions, which mainlywhich mainly centered centered on insular on insular and coastal and coastal areas. (areas.B) Bafat (Bá) region:Bafatá campregion: in camp Irancunda in Irancunda (Canadú );(Canadú); (C) Bijagó (sC archipelago) Bijagós archipelago (Agô Grande). (Agô Copyright, Grande). InstitutoCopyright, de Instituto Investigaç deã oInvestigação Científica Tropical Científica (IICT/Universidade Tropical (IICT/Universidade de Lisboa), de Portugal. Lisboa), Portugal. The aim of of this this paper paper is is to to review review the the accumulation accumulation of ofbotanical botanical knowledge knowledge on onWest West Africa Africa by byaddressing addressing historical historical aspects aspects of ofearly early plant plant records records and and studies studies made made in in the the former Portuguese continental coloniescolonies ofof this this region region and and particularly particularly in in what what was was known known as Portugueseas Portuguese Guinea, Guinea, today today the countrythe country of Guinea-Bissau. of Guinea-Bissau. Wedocument We document present present and past and botanical past botanical knowledge knowledge on the on region the region by means by ofmeans a critical of a surveycritical ofsurvey herbarium of herbarium collections collections and historical and historical literature literature on the territory’s on the territory’s flora. Important flora. inImportant this contribution in this contribution is the gradual is the shift gradual from shift native from to introducednative to introduced crops, particularly crops, particularly from the earlyfrom 1800s,the early mainly 1800s, for mainly commercial for commercial purposes. Three purposes. key periods Three regardingkey periods the regarding evolution ofthe knowledge evolution onof Guinea-Bissau’sknowledge on Guinea-Bissau’s flora and vegetation flora are and identified vegetation here, are namely: identified (i) early here, botanical namely: records, (i) early with botanical details onrecords, travel with accounts details and on reportstravel accounts of plants and and reports local vegetation of plants and between local vegetation the 15th and between 17th centuries; the 15th (ii)and botanical 17th centuries; explorations (ii) botanical from explorations the late 18th from to the the last late quarter 18th to of the the last 19th quarter century, of the with 19th details century, on Frenchwith details and Portuguese on French and naturalists’ Portuguese collections naturalists’ against collections the background against ofthe agricultural background change; of agricultural (iii) state sponsoredchange; (iii) botanical state sponsored missions botanical and studies missions from the and early studies 1900s from to the the end early of the 1900s colonial to the period end (1974).of the Ourcolonial contribution period (1974). attempts Our to contribution demonstrate attempts to what extent to demonstrate a longitudinal to what perspective extent upona longitudinal botanical explorationperspective upon can contribute botanical toexploration filling important can contribute gaps in to the filling knowledge important of the gaps flora in andthe knowledge vegetation of athe hitherto flora and neglected vegetation West of African a hitherto region. neglected West African region. Diversity 2018, 10, 109 3 of 14 2. Evolution of Knowledge on Guinea-Bissau’s Flora and Vegetation 2.1. Early Records of Botanical Knowledge The earliest records on the geographical area that currently includes Guinea-Bissau date back to the mid-15th century, when travelers, traders and chroniclers began to provide—as yet patchy—information on the climate, topography, flora and fauna, and human settlements [4–8]. One of the earliest accounts of West Africa is provided by Alvise Cadamosto in 1455–1456 [5] while visiting the Senegambian area. In his report Cadamosto referred to some main crops and staple foods, namely two kinds of grains, “large and small” (probably Sorghum bicolor (L.) Moench and Pennisetum glaucum (L.) R.Br., respectively), two types of beans and the oil palm tree (Elaeis guineensis Jacq.)