Arundo donax Linn.

Arundo donax Linn.

(Arundo donax Linn; Photo Harry Rose and maltawildplants.com)

Latin Name: Arundo donax Linn.

Family: Poaceae; Genus: Arundo

Synonym name: Aira bengalensis (Retzius) J. F. Gmelin; Amphidonax bengalensis (Retzius) Nees ex Steudel (1854), not Roxburgh ex Nees (1836); Arundo bengalensis Retzius; Arundo coleotricha (Hackel) Honda; Arundo donax var. coleotricha Hackel; Donax arundinaceus P. Beauvois; Donax bengalensis (Retzius) P. Beauvois; Scolochloa donax (Linnaeus) Gaudin.

English Name: Giantreed, Giant reed, Spanish reed.

Chinese Name: 芦竹 lu zhu

Description: Robust reed from a thick knotty rhizome. Culms very stout, erect, 2–6 m tall, 1–1.5 cm in diam., unbranched or with bamboolike clusters of slender branches from nodes. Leaf sheaths longer than internodes, usually glabrous except long pilose at mouth; leaf blades 30–60 × 2–5 cm, margins scabrous, tapering to a slender filiform apex; ligule 0.7–1.5 mm. Panicle 30–60 cm, dense, usually purplish; branches 10–25 cm, ascending. Spikelets 10–15 mm, florets 2–5; glumes narrowly lanceolate, 8–12 mm, 3–5-veined, lower glume acute, upper glume sharply acuminate; lemmas linear-lanceolate, 8–11 mm, 3–7-veined, dorsal hairs 5–6 mm, apex minutely bidentate with 1–2 mm awnlet from sinus, lateral veins also shortly extended; palea 1/2 length of lemma body. Flowering: October to December.

Distribution: Growing on stream banks, humid thick soil around houses. Distributed in Southwest and South China, Jiangsu, Zhejiang, Hunan and etc. The medicinal materials are mainly produced in Sichuan.

Part Used: Medical part: rhizome, juice extracted by heating stalk and young plant. Chinese name: roots and stem: Luzhugen. Juice extracted by heating stalk: Luzhuli; young plant: Luzhusun.

Harvest & Processing: Root and stem: collected the entire plant in summer, cut root and stem, well washed, removed fibrous root, sliced or sun-dried complete part. Juice extracted by heating stalks: fresh giantreed, cut into 30-50cm long, removed nodes, broke into two parts, heated the middle part to let juice flow out from two ends. Young plant: collected in spring, well washed and used fresh.

Physicochemical  properties  Ash:  2.39%,  extractives,  cold  water:  6.15%, hot water:   8.01%,   sodium   hydroxide   1%,   alcohol-benzene: 1.29%, dichloromethane: nodes 13.04% and  internodes11.16%,  ethanol:  nodes  5.88%  and  internodes 4.18%. 

Chemistry: Roots and stems contain indole derivatives, such as N, N-dimethyltryp-tamine,5-methoxy-N-methyl-tryptamine, dehydrobufotenine, etc. triacontane, α-amyrinacetate, β-amyrin acetate, triacontanol and campesterol, etc. Flowers contain indole derivatives, gramine and its Nb-oxide, gramine methohydroxide, N, N-dimethyltryp-tamine hydroxide, 3, 3'-bis(indolylmethyl) dimethyl ammonium hydroxide and eleagnine, etc.

Pharmacology: Decompressing, spasm-removing, slightly cholinomimetic or antiadrenergic, nervous-centralis of mammal exciting. Antibacterial and antifungal effects, Anthelmintic effects, Antifeedant activity, Antiproliferative effect, Effect on milk production and fattening performance, Central nervous effect, Effects on smooth muscles. Bufotenidine isolated from Arundo donax showed neuromuscular  blocking  activity, Arundo donax was  used  as  part  of  herbal    preparation      as    herbal  expectorant.

Properties & Actions: Root stem: bitter, cold, sweet. Juice from backed stem: bitter, cold. Tender: bitter, cold. Root and stem: clearing heat, reducing fire, promoting the production of body fluid, relieving restlessness and inducing urination. Juice extracted by heating stalks: clearing heat and removing restlessness. Young plant: clearing heat and reducing fire.

Indications & Usage: Rhizome: pyreticosis and dipsosis, osteopyrexia, hematemesis, pyretic stranguria, difficulty in urination, anemogenous toothache. Juice extracted from burnt stem: infantile chronic fever and infantile convulsions. Tender seedling: hematemesis due to lung-heat, osteopyrexia, dizziness, pyretic stranguria, otitis media, toothache. Rhizome: oral administration: decocting, 15-30g; or prepared plaster. External: appropriate amount, triturated for application. Juice extracted by heating stalks: oral administration: decocting, 15-30g. Young plant: oral administration: decocting, fresh 15-60g; or prepared plaster. External: appropriate amount, extracted juice for ear drippings.

Examples:     

1. Clearing lung heat, poisoned after eating plagued horse meat: take root and pestle natural juice, decoct and swallow.

2. Treat hematemesis due to lung heat: Giantreed sprout 500g, pestle juice, add white sugar and swallow.

Edible Uses

Rhizome - raw or cooked. The rhizome can be dried and ground into a powder to make bread, usually in conjunction with cereal flours. It can also be roasted or boiled. Leaves - cooked as a potherb. They are very bitter. The young shoots are used.

References

- Chinese Medicinal Material Images Database

- efloras.org

- theplantlist

- Ali Esmail, Al-SnafiAli, Esmail Al-Snafi (2015); The constituents and biological effects of Arundo donax - A review pharmacology of medicinal plants