Hyparrhenia rufa
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Hyparrhenia rufa Common Names: Jaraguá grass, Giant thatching grass,
Red thatching grass, Rooigras Scientific
Classification Kingdom: Plantae Clade: Tracheophytes Clade: Angiosperms Clade: Monocots Clade: Commelinids Order: Poales Family: Poaceae Genus: Hyparrhenia Species: H. rufa Synonyms: Andropogon rufus (Nees) Kunth, Cymbopogon rufus (Nees) Rendle, Sorghum rufum (Nees) Kuntze, Trachypogon rufus Nees Morphological Description Hyparrhenia rufa is a perennial, tufted C4 grass, typically 1–3.5 meters
tall, occasionally reaching 4 meters, forming dense clumps with short rhizomes.
Its key characteristics include: · Culms: Erect, robust, cylindrical, up to 1 cm in diameter, often
reddish at the base, forming dense tussocks (Fern, 2024). · Leaves: Linear, flat or folded, 30–60 cm long × 0.5–1 cm wide, with
a rough texture; leaf sheaths hairy, blades green to reddish (Prance &
Jongkind, 2015). · Inflorescence: Loose, terminal panicle (20–80 cm), bearing paired racemes
with 4–8 awned spikelets; spikelets covered in reddish-brown hairs, giving a
distinctive appearance (Kew Science, n.d.). · Seeds: Small, enclosed in spikelets with sticky awns, aiding
dispersal by adhesion to animals or wind (Skerman & Riveros, 1990). Distribution and Habitat Hyparrhenia rufa is native to Africa and widely introduced globally: · Geographic Range: Native to tropical and southern Africa
(Senegal to Ethiopia, south to South Africa); introduced to the Americas
(Brazil, Colombia, USA), Asia (India, Indonesia), and Australia; common in
Nigeria’s savanna and northern regions (Kew Science, n.d.). · Habitat: Thrives in savannas, open grasslands, disturbed areas
(roadsides, fallow fields), and riverine fringes; prefers well-drained, heavy
soils (pH 5.0–7.5) but tolerates occasional waterlogging; grows at elevations
up to 2,000 m with 500–2,000 mm annual rainfall (Fern, 2024). · Ecological Role: Competitive C4 grass, often dominant
post-fire or in overgrazed areas; supports soil stabilization but can reduce
biodiversity by outcompeting native species (Baruch et al., 1985). Ethnopharmacology Hyparrhenia rufa has limited direct ethnopharmacological documentation, but
its traditional uses in Nigeria and other African regions are noted, primarily
for non-medicinal purposes. Recent studies on related grasses suggest potential
medicinal applications, though specific pharmacological validation for H. rufa is scarce (Mongalo et al., 2015): · Wound Healing: In Nigeria, ash from burnt H. rufa culms is applied to wounds for its
antiseptic properties. While no direct studies confirm this, related Poaceae
species like Cymbopogon citratus exhibit antimicrobial activity due to terpenoids, suggesting
potential for H. rufa (Mongalo et al.,
2015). · Respiratory Relief: In Hausa communities, smoke from
burning H. rufa is inhaled to
relieve colds. This aligns with traditional uses of grasses for fumigation,
though specific volatile compounds in H. rufa (e.g., terpenes) require analysis
(Burkill, 1985). · Antipyretic Potential: In northern Nigeria, decoctions of H. rufa culms are used to reduce fever. While
unvalidated for H. rufa, phenolic compounds in
Poaceae grasses show antipyretic effects, indicating research potential (Irondi
et al., 2017). · Nutritional Support: Seeds are occasionally consumed in Nigeria
during scarcity, providing carbohydrates and fiber. Nutritional analysis shows
seeds contain 6–9% crude protein, supporting general health (Madubuike et al.,
1994). ⚠ Toxicity Profile: Hyparrhenia rufa is generally non-toxic and widely used as
livestock forage. It contains 0.85% oxalic acid, below levels causing oxalate
poisoning in cattle or horses. No significant human toxicity is reported,
though inhalation of smoke from burning grass may cause respiratory irritation
in sensitive individuals. Prolonged livestock grazing on mature plants may reduce
nutritional intake due to high fiber (29–43% crude fiber) and low protein
(1.5–9.2%). Allergic reactions to pollen are possible (Skerman & Riveros,
1990). Additional Uses · Forage: Primary use in Nigeria as fodder for cattle, goats, and
sheep; high biomass (up to 20 t/ha) but low protein (1.5–9.2%) requires
supplementation (Skerman & Riveros, 1990). · Thatching: Culms used in Nigeria for roofing due to durability and
water resistance; widely used in rural housing (Burkill, 1985). · Erosion Control: Dense root system stabilizes soils in
Nigeria’s savannas, used in agroforestry and land rehabilitation (Fern, 2024). · Cultural: In Hausa culture, culms are used in mats and baskets; burnt
grass in rituals for purification (Burkill, 1985). · Phytoremediation: In Nigeria, used to remediate
hydrocarbon-contaminated soils, enhanced by cow dung, showing high biomass and
pollutant uptake (Ruley et al., 2020). References
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