Genus Osteophloeum in Family Myristicaceae
In botanical taxonomy, a genus (plural genera) is a rank used to group closely related species within a family. In the hierarchy, genus sits below family and above species.
Genera are defined by shared morphological, anatomical, and genetic characteristics (for example, features of flowers, fruits, seeds, or leaves) that indicate a close evolutionary relationship among the species they contain.
Each genus can include one or more species. Examples include Rosa (roses) and Solanum (nightshades, including tomato and eggplant).
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Genus Description
Suggest a correction!Osteophloeum (Warb.) is a small genus in Myristicaceae and is generally treated as monotypic, centred on O. platyspermum (A.DC.) Warb., although some treatments list O. setosum as a second species and others treat both as synonyms of Virola (Gereau & Miller, 1996; Jørgensen et al., 2014). The trees are emergent to canopy elements of lowland Amazonian rainforests from northern Bolivia and eastern Peru into north‑central Brazil, with a scattering of collections across Venezuela and the Guianas (Sutter, 1984; GBIF, 2024). Within Myristicaceae the genus is distinguished by a combination of: densely rusty‑tomentose buds and often the lower leaf surfaces, entire leaf margins without notable venation reticulation, anthers that are fused into a short, wide connective plate (the “osteophloeum” or bone‑plate stamen), and fruits that are relatively large with a thin pericarp and a conspicuous aril that splits near the apex (Sutter, 1984).
Beyond the species‑rich and apparently polyphyletic Virola, Osteophloeum remains morphologically cohesive, forming a clade nested within the Myristicaceae–Virola complex in recent molecular analyses (Sauquet et al., 2003; Newmaster et al., 2006). Its distribution follows the extensive lowland terra firme forests and occasional varzea margins of western Amazonia, with disjunct outposts toward the Guianas and northern Bolivia; this pattern fits a Pleistocene‑era Amazonian “basin‑edge” distribution inferred for several Myristicaceae lineages (Sauquet et al., 2003). Some floral microcharacters further support its distinctness, including pollen features set apart from Virola (Sutter, 1984).
Human relevance is modest: the trees are occasionally encountered in local timber circles under vernacular names but are not widely exploited, and they have little documented ornamental use. Osteophloeum figures in checklists and treatments as a small, well‑circumscribed genus, and POWO lists a single accepted name while noting that historical treatments differ (POWO, 2024; WFO, 2024). Conservation data are fragmentary: range‑wide Red List assessments are not current, yet deforestation pressures in western Amazonia render many lowland Myristicaceae potentially vulnerable, highlighting the need for targeted population surveys and genetic diversity studies (Jørgensen et al., 2014; GBIF, 2024).