Brosimum

  • Authority

    Berg, Cornelius C. 1972. Olmedieae, Brosimeae (Moraceae). Fl. Neotrop. Monogr. 7: 1-229. (Published by NYBG Press)

  • Family

    Moraceae

  • Scientific Name

    Brosimum

  • Type

    Type species. Brosimum alicastrum Swartz.

  • Synonyms

    Alicastrum P.Browne, Piratinera, Ferolia Aubl., Galactodendrum, Brosimopsis, Piratinera guianensis Aubl., Brosimum guianense (Aubl.) Huber, Ferolia guianensis Aubl., Brosimum rubescens Taub., Galactodendrum utile Kunth, Galactodendron Rchb., Brosimopsis lactescens S.Moore, Brosimum alicastrum Sw.

  • Description

    Description - Monoecious or dioecious trees. Leaves entire, sometimes dentate or repand, with globose-capitate or oblongoid-capitate pluricellular hairs; stipules free or connate, fully amplexicaul or not. Inflorescences bisexual or unisexual, (sub) globose, hemispherical, turbinate, or convexly discoid, receptacle at first completely covered with peltate bracts; staminate flowers several to numerous, perianth well-developed and 4-3(-2)-lobed to 4-3(-2)-parted, vestigial, or lacking, stamens 4-1, anthers latrorse to extrorse, pistillode lacking; pistillate flowers one to several; testa with thickened part, sometimes vascularized, embryo transverse or oblique, cotyledons equal or unequal.

  • Discussion

    History.

    The genus Brosimum was described by Swartz in 1788. It was based on two species from Jamaica, B. alicastrum and B. spurium. Both species had already been described by Browne (1756), who named one of them, the so-called "breadnut," Alicastrum. This name, applied as genus name by Kuntze (1891), was rejected in favour of the commoner name Brosimum by the Botanical Congress at Vienna (1905).

    Trécul (1847) mentioned in his treatment of the Artocarpeae six Brosimum species: B. alicastrum, B. spurium, B. gaudichaudii Trécul (1847), B. aubletii Poeppig & Endlicher (1838), B. echinocarpum Poeppig & Endlicher (1838), and B. microcarpon Schott (1827). B. spurium was recognized as a member of the genus Pseudolmedia by Grisebach (1859), B. microcarpon as a Coussapoa species by Miquel (1853), whereas B. echinocarpum proved to belong to the genus Mayna (Flacourtiaceae). Although the genus was not well-founded at first, most of the more than forty species described hitherto were correctly added to the genus. In the meantime, however, Brosimum has had to compete nomenclaturally and taxonomically with several other genera. One of them, Piratinera, was described with one species by Aublet (1775). Piratinera guianensis was listed as a synonym of B. aubletii by Poeppig & Endlicher (1838). Thus they and Trécul regarded Brosimum and Piratinera as congeneric. This was generally accepted, but several authors (eg Baillon 1877) used the name Piratinera instead of the commoner genus name Brosimum. In 1905 Brosimum was made a nomen conservandum and Piratinera was rejected in favour of the former name by the Botanical Congress at Vienna. This was not accepted by those who still applied the rule of absolute priority. Greater confusion was brought about by the opinion of Pittier (1918), given in a study dealing with the generic status of Brosimum and Piratinera. He stated that thesegenera are to be regarded as distinct and well-founded. Although some studies of the wood anatomy appeared to give support to Pittieri opinion (cf Record & Mell 1924; Pfeiffer 1926), it was not generally accepted (cf Ducke 1922; Mildbraed 1927; Macbride 1937). However, even in recent taxonomic literature one may meet with Brosimum and Piratinera treated as separate genera, in spite of the weakness of the differentiating characters mentioned by Pittier. It is remarkable that Pittier in the same paper decribed three Helicostylis species (Olmedieae), which proved to belong to the genus Brosimum.

    In 1895 Spencer Moore described the genus Brosimopsis, with B. lactescens, and placed it in the Euartocarpeae. Ducke (1922) transferred it to the Olmedieae. Ducke found similarities with Brosimum, but he placed Brosimopsis in the Olmedieae mainly on account of the occurrence of unisexual inflorescences. In 1939 he added some other differentiating characters found in the wood and the latex. He also described several new Brosimopsis species and transferred Brosimum acutifolium to this genus.

    The position of the genus Ferolia Aublet (1775), with F. guianensis, was for long doubtful. Mainly on account of the (unclear) description of the "fruit", Jussieu (1789) referred Ferolia with doubt to Parinarium), a genus of the Chrysobalanaceae. Baillon (1877) referred Ferolia to Piratinera, also with doubt. Lanessan (1886) and Pfeiffer (1926) took up F. guianensis and regarded it as related to Piratinera. Huber (1910) pointed out the similarities between F. guianensis and Brosimum paraensis, and their conspecificity could be confirmed by study of the type specimen of F. guianensis (cf Berg 1968). Standley (1929), in discussing the history of the genus Ferolia, pointed out the consequences for the nomenclature of Brosimum, as Brosimum was not conserved against Ferolia.

    The genus Galactodendrum was described by Kunth in a footnote to an account by Humboldt & Bonpland (1819) dealing with the so-called cow tree (palo de vaca). The species G. utile was published later (Humboldt, Bonpland & Kunth 1825). The species was associated with Brosimum and was soon included in that genus (cf Sweet 1830).

    Habit.

    Brosimum is a genus of trees, which in many species may reach a considerable height and which in some species may have buttresses. Plants of B. gaudichaudii, inhabiting mainly the campos cerrados of central South America, are predominantly small trees or shrubs.

    Latex.

    The trees yield white or yellowish latex, in some species in large amounts. There seem to be distinct differences in the characters of the latex. According to Ducke (1939) it bitter in Brosimum lactescens and B. acutifolium but has a sweet taste at least in B. alicastrum and some species of Brosimum subgen Ferolia.

    Indument.

    Uncinate hairs are found on leaves, twigs, and or inflorescences in all species. In some species they are met with in most specimens, in others only in a few specimens. They are especially common in juvenile specimens. The pluricellular hairs, mainly found on the lower leaf surface, are globose-capitate to ovoid-capitate in Brosimum subgen Brosimum, oblongoid-capitate to ovoid-capitate in Brosimum subgen Ferolia. In B. utile they are more or less sunken.

    Leaves.

    These are mostly more or less inequilateral. Their margins are mostly entire, but often dentate in B. gaudichaudii. The leaf margin is repand in one subspecies each of B. utile and B. parinarioides. The stipules are fully amplexicaul and connate in subgenus Ferolia, but free and not fully amplexicaul in subgenus Brosimum; they are usually caducous.

    The leaves of B. potabile have stomatal crypts. Less distinct stomatal crypts in B. parinarioides. Papillate epidermal cells are found on the lower leaf surface of all species of section Piratinera, in B. alicastrum, in B. potabile, and in several specimens of B. utile. In B. utile and B. alicastrum the epidermal papillae are short and confined to the stomatal areas. In B. potabile the epidermal papillae gradually pass into hairs. In the species of section Piratinera the epidermal papillae may be rather long, especially around the stomata, where they may form more or less distinct extra-stomatal chambers; they are usually not confined to the stomatal areas. Crystal-containing cells occur in the species of subgenus Brosimum, except perhaps in B. glaucum. Such cells are not found in the species of subgenus Ferolia.

    Inflorescences.

    To the remarks about the inflorescences and flowers of Brosimum made in the general part, the following may be added. The inflorescences are sometimes convexly discoid to turbinate (eg in many specimens of B. guianense), but mostly hemispherical or (sub)globose. In several species, especially of the subgenus Ferolia, the inflorescences are more or less lobed and foveate, so that they may show some resemblance to cauliflowers. In the pits of the receptacle, staminate flowers, or in several cases actual stamens may be found.

    Brosimum lactescens and B. costaricanum are the only species in which the staminate flowers may be complete by having a well-developed perianth with 4 segments and well-developed stamens. In B. lactescens the number of stamens may be reduced to 2. All intermediates between complete flowers and those with fewer tepals and only 2 stamens may be found. In B. utile subsp allenii most staminate flowers have rather well-developed perianths and 2 stamens; in other subspecies the perianth is vestigial and the number of stamens is reduced to one; while in the Amazonian subspecies the perianth may be wanting. In several species, eg the closely related species B. gaudichaudii, B. glaucum, and B. glaziovii, the perianth is lacking. In these three species, however, the perianth appears to be replaced by a modified perianth-like bract. In B. acutifolium one to three bracts may form a perianth-like structure. The developing stamens of the species lacking a well-developed perianth are protected by the bracts, that cover the whole surface of the flower-bearing part of the receptacle at first, in some species also by perianth-like bracts, and in the species with foveate receptacles also by perianth-like bracts, and in the species with foveate receptacles also by the position of the staminate flowers. The anthers are latrorse, or extrorse if, as in most cases, the connective is broad. The anther often makes an angle up to 90° with the filament. In B. alicastrum subsp alicastrum the thecae are fused, giving a peltate anther, which opens circumscissilly.

    The number of pistillate flowers is variable. As a rule, the inflorescences contain one central flower, but in several species they may have occasionally or often more flowers.

    Infructescences.

    When the fruits are mature the enlarged receptacles become yellow or reddish. They are then pulpy and appear to have a sour-sweet taste. The receptacles are probably eaten and the fruits are dispersed by fruit-eating animals. The large seeds have a thin testa, showing laterally, just below the hilum, a (sub)orbiculate thickened part. Vascular bundles are found in the testa of some species; they are almost confined to the thickened part of the testa. The cotyledons are equal or unequal. In subgenus Brosimum one of the cotyledons is beaked.

    Taxonomic notes.

    In the past the strong differentiation within the genus caused problems in delimitation, and, in connection with that, in the separation of genera like Piratinera and Brosimopsis. The characters on which these were based, such as the number of pistillate flowers, the shape of the receptacle (cf Pittier 1918), and the sexuality of the inflorescences (cf Ducke 1922, 1939; see p. 163), appear to be useless for the separating genera.

    The genus falls into two groups which are treated here as subgenera, Brosimum and Ferolia. Their main differentiating characters are described in the taxonomic part. Subgenus Ferolia, comprising five species, is rather uniform, unlike subgenus Brosimum. In this latter subgenus three sections are distinguished. As will be clear from the systematic arrangement of the species, the sections do not agree with the former satellite genera of Brosimum, although their names are employed for these taxa. Section Piratinera comprises B. guianense and the closely related species B. gaudichaudii, B. glaziovii, and B. glaucum\ section Brosimopsis, mainly based on characters of the staminate flowers, comprises B. lactescens and B. costaricanum; and section Brosimum includes the remaining species, B. alicastrum and B. acutifolium. The subdivisions of the genus are based chiefly on morphological characters.

    The species are variable to different extents. Some of them, like B. costaricanum, B. glaucum, B. glaziovii, and B. melanopotamicum, all with small areas, are uniform. The others, mostly with more extensive areas, are more or less strongly diversified. In a number of them (eg B. utile and B. acutifolium), regional discontinuities in the morphological variation allow the distinction of subspecies. In others (eg B. rubescens, B. lactescens, and B. guianense), the morphological differences are not important, are not clearly geographical, and/or are connected by many intermediate forms, so that subspecies cannot be distinguished. Brosimum gaudichaudii and B. guianense are examples of species with more or less continuous, less important variations; in B. guinense differences in the indument of the leaves are not distributed at random, but are more or less geographically concentrated. In B. lactescens and B. rubescens the morphological differences are somewhat geographically concentrated and partly distributed in a mosaic-like fashion, especially in the Amazon Basin; moreover, the variations are connected by intermediate forms.

    Use.

    Some species, especially Brosimum guianense and B. rubescens, furnish valuable timber. Seeds of B. alicastrum (breadnut) are eaten and its leaves are used for cattle fodder. The latex of several species (B. utile, B. potabile, and B. alicastrum) is potable. The latex of B. parinarioides and B. utile (subsp longifolium) is applied against lung diseases, that of B. alicastrum is said to stimulate lactation. The latex of B. parinarioides is sometimes used to adulterate balata. That of B. acutifolium (subsp acutifolium) is poisonous; it causes unconsciousness when drunk.

  • Distribution

    The area of the genus Brosimum ranges from Mexico and the Greater Antilles, Cuba, and Jamaica, to southern Brazil. Subgenus Ferolia is almost confined to South America; all sections of subgenus Brosimum are also represented in Central America. Some species, eg B. alicastrum, B. guianense, and B. lactescens, occupy extensive areas. The distribution of B. lactescens seems to be continuous, but the species does not seem to be equally common in all parts of its area, which extends from Mexico to sou

    Mexico North America| Cuba South America| Haiti South America| Dominican Republic South America| Puerto Rico South America| Jamaica South America| Cayman Islands South America| Brazil South America| Venezuela South America| Guyana South America| French Guiana South America| Suriname South America| Central America| Colombia South America| Ecuador South America| Peru South America|