PlantaeDB Logo
Login Sign-up

Genus Elionurus in Family Poaceae

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).

Do you wish to read more about plant taxonomy? Click here!

Genus Description

Suggest a correction!

Elionurus (Humb. & Bonpl. ex Willd.) is a genus in the grass family Poaceae, placed in tribe Andropogoneae (subfamily Panicoideae). It includes about 15–20 species of caespitose or rhizomatous perennial grasses, with the type species E. elegans often cited in regional treatments (Clayton et al., 2006). The genus is widespread across tropical and subtropical Africa, with extensions into Madagascar and the Comoros, and smaller distributions in southwestern Asia, northern Australia, and parts of Central and South America; most taxa occur in savanna woodland, grassland, and seasonally dry scrub, typically at low to mid elevations (POWO, 2024; WFO, 2024; Van Welzen, 1999).

Morphologically Elionurus is distinguished by dense, often compact inflorescences that are solitary or paired and comprise one to several racemes. The raceme rachis is frequently flattened or winged, and a distinctive feature is a pair of minute, ear-like appendages at the base of each raceme that in many species overlap to form a “clip” around the paired sessile and pedicellate spikelets (Clayton et al., 2006). The glumes are typically membranous to slightly indurated, and the lemmas are awned or unawned; the sessile spikelet is usually bisexual, the pedicellate spikelet male or sterile. Plants bear leaf blades that are linear, often flexuous, and the inflorescences are subtended by an involucre of flag leaves that are sometimes conspicuous (Clayton et al., 2006). The fruit is a caryopsis, and the ovary bears basal appendages characteristic of Andropogoneae.

Diversity and range centers are in southern and eastern Africa, where several narrow endemics occur in Kenya, Tanzania, and the Zambezian region (Clayton et al., 2006). Elsewhere the genus is more widespread but generally low in species density, reflecting adaptation to seasonally arid environments. Little species-level detail is well supported across continents, so regional floras and regional networks record the genus but emphasize the need for revision (GBIF, 2024).

Intrinsic biology remains poorly documented beyond general andropogonoid traits. The ear-like raceme bases and compact inflorescences likely facilitate wind capture and spatio-temporal structuring of pollen release, although specific pollination syndromes are not resolved (Clayton et al., 2006). Seed dispersal appears to rely on the caryopsis and associated structures typical of savanna grasses; chromosome numbers are reported inconsistently and are not robustly synthesized (Clayton et al., 2006).

Taxonomically, Elionurus is stable at generic rank, although species delimitation varies among treatments. Several taxa originally described in Elionurus from the Americas have been transferred to Schizachyrium in some accounts (Van Welzen, 1999; Peterson et al., 2015), reflecting the fine morphological boundaries that separate these closely related andropogonoid genera. This difference underscores the need for molecular phylogenetic testing and consistent typification across regions; current evidence supports circumscribing Elionurus with Old World taxa, while Old World taxa are retained within Elionurus or Schizachyrium inconsistently (Peterson et al., 2015). Such variation means “about” is appropriate when quantifying species richness and distribution (POWO, 2024; WFO, 2024).

Human relevance is modest. Elionurus species contribute to natural forage in savanna systems but are not major cultivated crops or timber sources, nor are they widely used as ornamentals (Clayton et al., 2006; Van Welzen, 1999). Weedy behavior is not prominent, and global invasions are not recorded (GBIF, 2024).

Conservation and outlook are constrained by uneven taxonomy and distributional gaps; targeted field surveys and DNA-based revisions are needed to resolve species boundaries, clarify the Schizachyrium relationship, and evaluate potential threats to regional endemics (Peterson et al., 2015; Clayton et al., 2006).

Pick a Species to see its components: