Gen info
- Acalypha is a genus of flowering plants in the family Euphorbiaceae. It is the sole genus of the subtribe Acalyphinae. It is one of the largest euphorb genera, with about 450-462 species.
- The genus name Acalypha is from Ancient Greek akaluphe, meaning "nettle", referring to the nettle-like leaves.

Botany
Large shrubs, 2–5 m tall, monoecious; flowering branches 25–30 cm long, 2–5 mm diam. Indumentum glabrous to hairy, denser on young parts, with simple straight hairs. Stipules persistent, ovate to narrowly elliptic, 10–25 by 2–5 mm, midrib outside hairy and with capitate trichomes. Leaves: petiole 2–15 cm long, glabrous or with sparse straight hairs of 0.5–1 mm long; blade ovate to elliptic, 9–20 by 5–8 cm, length/width ratio 1–2.5, chartaceous, not variegated, green when fresh; base acute to weakly cordate, with a pair of glands of 1–2 by c. 0.5 mm, and scattered glandular trichomes; margin serrate, teeth 1–2 by 2–3 mm, with a gland on tooth tip; apex acute to acuminate; upper surface nearly glabrous, lower surface sparse to densely hairy, surfaces flat or slightly sunken between the veinlets; base 3-nerved, upper secondaries 5–8 per side. Staminate inflorescences  axillary, 1 per axil, spicate, in different axils than pistillate ones; peduncle 5–40 mm long, indumentum velvety, hairs to 0.2 mm long; fertile portion 80–245 by 1.5–2.5 mm, internodes 1–3 mm long. Staminate flowers: bract ovate, 0.5–1 by 0.3–0.5 mm, with outside sparse hairs of c. 0.2 mm long; pedicel 0.5–1 mm long, with straight hairs to c. 0.2 mm long; calyx 0.5–1 mm diam, sepals ovate to elliptic, c. 0.5 by 0.2–0.3 mm, with straight hairs to c. 0.2 mm long, midrib verrucate in distal half, apex acute; filaments c. 0.3 mm long, thecae 0.3–0.4 by c. 0.2 mm. Pistillate inflorescences  axillary or terminal, solitary, spicate, straight, many-flowered, in different axils than staminate ones; peduncle 8–20 by 1.5–2 mm long, nearly glabrous; fertile portion 9–30 by 0.3–1 cm, internodes 2–10 mm long. Pistillate flowers 1–1.5 mm diam; 1 or 2 per bract; bract stipules ovate to elliptic, 0. 5–1 by 0.25–0.5 mm; bracts sessile, 4–10 by 4–9 mm, foliaceous, accrescent, strongly veined outside, without dots, sparsely hairy outside, sometimes with short capitate trichomes, inside with sparse sessile glands; bract teeth 9–13, apical tooth 0.75–1 by c. 0.5 mm, apex acute to obtuse, lateral teeth 0.5–1 by 0.75–1 mm, apex acute; pedicel 0(–0.5) mm long; calyx 1–1.5 mm diam, sepals 3, ovate to elliptic, 0.75–1.5 by c. 1 mm, hairy outside, without verrucae, glabrous inside; ovary globose, c. 1 by 1 mm, trilocular; stigmas 3, 2.5–5 mm long, each 4–6 times divided, base hairy. Bisexual inflorescences  absent. Fruits  globose, 2–2.5 by c. 1.5 mm, verrucate, covered with bulbous-based trichomes, columella 1.5–2 mm long. Allomorphic fruits  unknown.  Seeds prolate, 1–1.5 by c. 1 mm.

Distribution
- Native to the Philippines.
- Also native to Borneo, Caroline Is., Maluku, New Guinea, Sulawesi.

Constituents
- Aqueous leaf extract yielded alkaloid, phenol, flavonoid, tannin, and saponin, supported by functional groups like carboxylic acid, alcohols, amine, conjugated alkene, aromatic esters, and alkyl aryl ether. (see study below) (3)

Properties
Studies have suggested antibacterial properties.

Parts used
Stem sap, leaves.

Uses
Folkloric
- Stem sap used to treat eye wounds or cataracts.
- In Mindoro, used for treatment of ringworm, (3)
Others
- Wood: Tree used for fencing.

Studies
• Antibacterial / Leaves: Study evaluated the phytochemical constituents and antibacterial activity of lyophilized aqueous leaf extract of Acalypha amentacea using agar-well diffusion. Dose of 500 mg/ml showed high zones of inhibition for Staphylococcus aureus (21.78 mm), Escherichia coli (21.36 mm), Serratia marcescens (21.90 mm), Klebsiella pneumonia (21.44 mm), and Enterococcus faecalis (20.52 mm). Compared to antibiotic Rifampicin, A. amentacea exhibited better bioactivity against all the tested bacteria except for S. aureus (p<0.05) and comparable to Ofloxacin against E. faecalis. Activity may be attributed to some of its photoconstituents i.e., alkaloid, phenol, flavonoid, tannin, saponin. (see constituents above) (3)
• Antibacterial against MRSA / Leaves: Study of ethanolic extract of A. amentacea leaves for antimicrobial activity using paper disc diffusion and spot testing assays showed inhibition of growth of MRSA (methicillin-resistant Staphylococcus aureus). It was ineffective against E. coli and metallo beta-lactamase producing Pseudomonas aeruginosa. (4)

Availability
Wild-crafted.

Additional Sources and Suggested Readings
(1)
Acalypha amentacea / KEW: Plants of the World Online
(2)
(3)
Antibacterial activity of the lyophilized aqueous leaf extract of the Philippine green-leafed Acalypha amentacea Roxb. (Maslakot-Ambulong) against selected human bacterial pathogens / Romnick Ureta, Gary Antonio C Lirio, Ma Peach Navarro Ogbac, Zandre Isabelle Cruzado / Malaysian Journal of Microbiology, 2019; 15(6): pp 463-470 / DOI: 10.21161/mjm.180323
(4)
Antibacterial property of ethanolic leaf extracts from Ficus septica (Hauili fig tree) and Acalypha amentacea (Balingud) along Wawa Dam, Rodriguez, Rizal against selected multidrug resistant bacteria / / James Lyle Benedict M Doctolero, Maria Daniela J Robles / Bachelor's Thesis, 2019: BS in Biology / Animo Repository
(5)
Performance of TiO2 based dye-sensitized solar cells fabricated with dye extracted from leaves of Peltophorum pterocarpum and Acalypha amentacea as sensitizer / P Sanjay, K Deepa, J Madhavan, S Senthil / Material Letters, 2018; Vol 219: pp 158-162 / DOI: 10.1016/j.matlet.2018.02.085

DOI: It is not uncommon for links on studies/sources to change. Copying and pasting the information on the search window or using the DOI (if available) will often redirect to the new link page. (Citing and Using a (DOI) Digital Object Identifier)