Genus Caesulia in Tribe Inuleae
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!Caesulia (Roxb.) is a small genus of the Asteraceae, comprising roughly five herbaceous species native to the Indian subcontinent and nearby regions of Southeast Asia (Hind, 2020; POWO, 2024). The type species, originally described as Caesulia alata (L.) DC., is now treated as a synonym of Laggera alata (L.) DC., which serves as the nomenclatural reference for the group (WFO, 2024).
Plants are erect or prostrate herbs with opposite, simple leaves lacking stipules. The compact capitula are arranged in corymbs or panicles; each head bears several lanceolate phyllaries and a few white to pale pink florets. Corollas are tubular with five short lobes; the inferior ovary bears a single basal ovule and the fruit is a small achene crowned by a pappus of fine bristles that aids wind dispersal (Govaerts et al., 2020; Hind, 2020).
Species are concentrated in the Western Ghats and the Himalayan foothills, with a few taxa extending to Sri Lanka, Bangladesh and northern Myanmar (WFO, 2024). They occupy lowland to mid‑elevation disturbed sites, forest margins and grassy slopes, often appearing as early‑successional elements of secondary vegetation (Hind, 2020).
Generalist insects—bees, flies and small beetles—frequently visit the capitula and serve as primary pollinators (Hind, 2020). The achenes bear a pappus of numerous fine hairs, facilitating wind‑assisted dispersal; some populations also show secondary ant‑mediated transport when seeds fall beneath the parent plant.
Roxburgh originally described Caesulia as a distinct genus within the tribe Inuleae of Asteraceae, but later treatments placed it among the core Laggera clade. Molecular phylogenetic analyses (Hind, 2020) demonstrated that Caesulia is nested within Laggera, leading to the synonymization of all former Caesulia species under Laggera in the major global checklists (POWO, 2024; WFO, 2024). Regional floristic works sometimes retain Caesulia as separate, stressing the characteristic pappus (Fuentes & Bagchi, 2015), although this view is not followed by the principal databases (Govaerts et al., 2020).
The genus has limited horticultural use; a few species are occasionally cultivated for modest white flower heads, while others are minor weeds in rice and millet fields (Govaerts et al., 2020). No significant timber or food crops are derived from Caesulia.
Deforestation, agricultural expansion and urban development threaten several narrow‑endemic populations; a coordinated field survey is needed to assess their conservation status and guide future management.