Taxonomic History of Humiriaceae

Abstract

A more detailed species-by-species taxonomic history of the family is given in Cuatrecasas (1961) and only the major contributions before that date are highlighted here. The first genera of Humiriaceae were described and illustrated by Aublet (1775), Houmiri Aubl., with the single species H. balsamifera (later Latinized to Humiria) and Vantanea guianensis Aubl. Aublet placed these genera in the class Polyandria and order Monogynia of the Linnaean system. Nees and Martius (1824) described the genus Helleria, which was later placed in synonymy with Vantanea Aubl. (Bentham 1853). Martius (1827) described the genus Sacoglottis with a single species S. amazonica and also Humirium floribundum (now a variety of Humiria balsamifera). He considered these genera to be related to Meliaceae, Symplocaceae, and Styracaceae, an opinion supported by Endlicher (1840). Jussieu (1829) was the first to treat the group at the family level including two genera: Humirium with two species and Helleria of Nees and Martius (1824) also with two species that are now in Vantanea. He also recognized Sacoglottis as belonging in this family, so in effect he brought together all three genera of the family that had been described by 1829. Planchon (1848) compared the Humiriaceae with Erythroxylaceae and the Linaceae due to morphological affinities to Erythroxylum P. Browne and Roucheria Planch, respectively. Bentham (1853) published a concise summary of the family treating the three genera Humiria, Sacoglottis, and Vantanea. The separation of these genera was mainly based on the number of stamens, Vantanea with numerous stamens, Humiria with 20 stamens, and Sacoglottis with 10 stamens. He also noted the number of ovules, two in Vantanea and one in Sacoglottis, but Humiria with one or two ovules. Baillon (1873) united all known Humiriaceae into the single genus Houmiri, which included 15 species placed in five sections: Humirium (20 stamens), Aubrya (10 free stamens), Saccoglottis (10 stamens + 10 staminodia), Vantanea (20–60 stamens), and Vantaneoides (never formally published), and the genus was placed in his Linaceae. Baillon (1874) repeated the same division of Humiriaceae and placed his series Humiriées in the Linaceae. The next major contribution to the family was by Urban (1877) in Martius’ Flora brasiliensis. Urban recognized three genera: Humiria with three species, Saccoglottis with nine species, and Vantanea with four species. Saccoglottis was grouped into three subgenera: Eusaccoglottis with two Brazilian species but recognizing that the African Aubrya gabonensis of Baillon (1862) belonged here; subgenus Humiriastrum with three species; and subgenus Schistostemon with four species. Urban divided the family into two groups distiguished by the number of stamens and number of cells in the thecae of the anthers: Vantanea with thecae with two locules and many stamens and Humiria and Saccoglottis with unilocular thecae and fewer stamens. The subgenera were divided by staminal characters: subg. Eusaccoglottis with 10 stamens, subg. Humiriastrum with 20 undivided stamens, and subg. Schistostemon with 20 stamens, the latter with 5 tridentate ones bearing 3 anthers. Urban (1893) later described Sacoglottis glaziovii Urb. based on material sent to him from Brazil, and this was transferred to Humiriastrum by Cuatrecasas (1961). Hallier (1921) followed Baillon in keeping the Humiriaceae and Linaceae united into a single family. Ducke (1922–1933; 1935–1937) in a series of important papers about Amazon plants published four new species of Vantanea and five of Sacoglottis, as well as several new varieties. Two of Ducke’s new species of Sacoglottis were later given generic status by Cuatrecasas (1961) one named appropriately Duckesia (after Adolpho Ducke whose work was a major contribution to the taxonomy of the Amazonian species of Humiriaceae) and the other Hylocarpa. Ducke (1938) summarized much of his work on Humiriaceae and provided a key to the genera Sacoglottis and Vantanea, placing them in Linaceae. Winkler (1931) in the second edition of Pflanzenfamilien followed Baillon and Hallier in including the family in Linaceae, but as the subfamily Humirioideae. Otherwise Winkler (1931) followed Urban’s system without any changes.