The history of the BR herbarium should of course be seen in the context of the history of the entire institute). With regard to the proper history of the herbarium, a number of events are here enumerated in a chronological order. See also the "BR gallery".
Note. It is clear that the herbarium of the non-vascular cryptogams, curated separately between 1902 and 1909 and from 1966 onwards, has had a very similar history and acquisition history. The present text, however, focuses on the vascular plant herbarium kept by the Department Spermatophyta-Pteridophyta of the Garden.
A chronology of events
1826 establishment, in Brussels of the 'Koninklijke Maatschappij van kruid-, bloem- en boomkweekerije der Nederlanden' (Royal Society for horticulture and arboriculture of the Netherlands), under the Dutch rule; apart from a botanical garden, a botanical library and a herbarium were assembled. Collections in BR marked with a stamp 'Herb. Hort. Bruxell.' (e.g. the "Religieuse mailleanae", specimen example 841524) might well date from acquisitions between 1826 and 1870 (no precise information located yet)
1837 change of the name of the Society into 'Société Royale d'Horticulture de Belgique' (sometimes cited as 'Société Royale de Flore')
c. 1840-1858 directorship of the 'Société' to H. Galeotti, botanical explorer of Mexico; it is not clear in how far he assembled his own herbarium (ca. 8000 Mexican specimens) at the 'Société' (many of these collections came later to BR, see 1932)
1870 buildings and properties of the 'Société' purchased, through the intervention of B. Dumortier, by the Belgian government to become the 'Jardin botanique de l'Etat'. In 1871 the famous Herbarium Martii (300,000 specimens belonging to 60,000 species), acquired by the Belgian government the year before) was incorporated in the herbarium (from then onwards the Jardin Botanique de l'Etat was organized in three sections: living collections, herbarium, and plant products)
1885 establishment of the Independent Congo State; agreement with its state secretary Baron van Eetvelde to assemble herbarium specimens from the Congo in the Garden
1887-1888 Frans Hens, a painter from Antwerp, was the first Belgian to collect plant specimens in the Congo (the exploration of which had begun with the British Christian Smith in 1816, followed by many British and Germans, e.g. Cameron, Schweinfurth, Büttner, Pogge); other early Belgian explorers of the Congo include Fernand Demeuse (1891-1893; thousand of his specimens were however lost in a shipwreck), father Justin Gillet (1893-1943), Emile Laurent (1893 and 1895-1896; specimen example: 837806 specimen example: 837830 )
1895 Théophile Durand and Emile De Wildeman are charged with the study of the flora of the Congo
1895-1896 Alfred Dewèvre (specimen example: 837829) was charged with the very first official mission by the Independent Congo State for a botanical exploration; his journey should take two years, but he returned earlier due to health problems, and died in the Lower Congo before he could embark; his collection (about 1200 numbers) remained unlabeled until the rediscovery of his original field notes in 1965
1898-1907 publication, by the same Emile De Wildeman and Théophile Durand, of a compilation of the contents of the Herb. Belg., the Prodrome de la flore Belge (3 volumes)
1899 new herbarium building inaugurated
1902 division of the section herbarium into two sections, phanerogams and ferns under De Wildeman, cryptogams and plant diseases under Paul Nypels; the sections were united again in 1909
1909 summary of the early botanical exploration of Congo in the Sylloge Fl. Congol. (see Taxonomic Literature entry 1595)
1914 acquisition of the private herbarium Van den Bossche ("Herbarium Horti Thenensis"; 12,990 specimens). Information in De Wildeman, Icon. horti then. & Pl. nov. horti then. (Taxonomic Literature entries 1429 & 1434).
1916 acquisition of the private herbarium of Alfred Cogniaux (5251 specimens: 1263 Cucurbitaceae, 3997 Melastomataceae and 11 orchids) But the bulk of orchid fragments collected by him probably was acquired later or not counted
1931 building of two new herbarium rooms and transformation of the basement into herbarium room. Note that the report 1925 mentioned: A... les armoires destinées à contenir l'herbier deviennent insuffisantes. Pour certaines familles ... les disposer sur les tables ou les armoires où ils se couvrent de poussière.
1932 collection Martin Martens (University Louvain) given by Pierre Martens (it contains inter alia many Galeotti specimens)
1934 herbarium of the Congo Museum (Tervuren) transferred to the Garden, including inter alia the collections of Corbisier-Baland (specimen example: 837831)
1935-1970 no doubt the most intensive period for the botanical exploration of Congo, mainly due to the activity of two institutes. The INEAC (Institut National pour l'Etude Agronomique du Congo) had a botany department undertaking a global botanical inventory, with several research stations (Luki, Mulungu, Yangambi, ...) throughout the country. It was carried out by numerous collectors, to name a few Devred, Gilbert, A. Léonard, J. Léonard, Pierlot. Among these Jean Louis (specimen example: 837825) no doubt assembled, from 1935 to 1939, the best collection from the Congo Basin (17,000 specimens with very complete labels, all represented by two sheets in BR). The Institut des Parcs Nationaux du Congo on the other hand made a systematic exploration of the National Parks (collectors inter alia de Witte, de Saeger, Lebrun
1939 acquisition by the state of the Bouchout Domain (93 hectares) from the Royal family to constitute a new location for the Botanic Garden; the herbarium and library building in the Domein van Bouchout was finished in 1958
1966 establishment of two research departments, 'Spermatophyta-Pteridophyta' and 'Bryophyta-Thallophyta' responsible for the curation of the vascular plant herbaria and the herbaria of non-vascular cryptogams
1969 publication of a list of endangered and rare vascular plants of Belgium (Delvosalle, Demaret, Lawalrée and Lambinon), based on the comparison of herbarium specimens and recent chorological information; one of the first 'Red Lists' on the European continent (if not the first)
1974- 1975 transfer to the herbarium building in Bouchout Domain (collections of the department Bryophyta-Thallophyta in 1974, those of the department Spermatophyta-Pteridophyta in 1975)
1997 acquisition of the private batological herbarium of J.Van Winkel (more than 20,000 Rubus specimens from Belgium and W Europe)
1999 ca. 90,000 specimens of the herbarium of the Carnoy institute (LV)
are given by the Catholic University of Leuven, inter alia with Schimper
collections from Ethiopia
