Close-up views:

The young plants:

The overall appearance of this plant resembles that of the Indian Borage (Plectranthus amboinicus). One feature that differentiate them is the characteristic of the stem. Plectranthus monostachyus has a 4-angled stem while that of Indian Borage is round. Some matured plants seemed to have nodules among its roots. Additionally, it seemed that Indian Borage rarely bears flowers in Singapore while Plectranthus monostachyus can be seen flowering all the time under sunny condition.

The synonym Solenostemon monostachyus is used more often when referring to this herb. The transferred of Solenostemon monostachyus to Plectranthus was described in a publication by Kew in 2001 [1].

The first time that I came across this herb in Singapore was in 2007 at Sungei Buloh Wetland Reserve, around the outdoor classroom area. A large population could be seen thriving on a deserted plot that was used to grow some other herbs in the past. Over the years, I started to see more of them in other open areas. The herb was not listed in the Singapore flora checklist published in 2009. The official status of this herb in Singapore was finally established in a local publication in 2015 [2]. Interestingly, Indian Borage (Plectranthus amboinicus) mentioned in the same article was also not listed in the 2009 plant checklist although it is a common cultivated herb here.

Its native range is tropical West Africa. It is no wonder that there are many articles published over the years from that region on its potential medicinal potential [3-11].

References:

[1] Pollard BJ, Paton A. A New Rheophytic Species of Plectranthus L'Her. (Labiatae) from the Gulf of Guinea. Kew Bulletin 2001;56(4):975-982.

[2] Chung YS, Teo S, Chong KY, Kurukulasuriya BR, Tan HTW. Weed risk assessments of the exotic species of Plectranthus L'Her. (Lamiaceae) in Singapore. Nature in Singapore 2015;8:1-13. | Read article |

[3] Okokon J, Davis KA, Azare BA. Antipyretic and antimalarial activities of Solenostemon monostachyus. Pharm Biol 2016;54(4):648-653.

[4] Okokon JF, Davis K, Nwidu LL. Anti-inflammatory and antinociceptive activities of Solenostemon monostachyus aerial part extract in mice. Avicenna J Phytomed 2016;6(3):284-294. | Read article |

[5] Gbadamosi IT, Oloyede AA. The mineral, proximate and phytochemical components of ten Nigerian medicinal plants used in the management of arthritis. Afr J Pharm Pharmacol 2014;8(23):638-643.

[6] Afolabi IS, Osikoya IO, Fajimi OD, Usoro PI, Ogunleye DO, Bisi-Adeniyi T, Adeyemi AO, Adekeye BT. Solenostemon monostachyus, Ipomoea involucrata and Carica papaya seed oil versus Glutathione, or Vernonia amygdalina: methanolic extracts of novel plants for the management of sickle cell anemia disease. BMC Complement Altern Med 2012;12:262. | Read article |

[7] Okoko T, Ere D. Antioxidant activities of Solenostemon monostachyus leaf extract using in vitro methods. Sci Res Assays 2012;7:621. | Read article |

[8] Fidele KZ, Andre KB, Yao DJ, Michel OA. Action of hydroethanolic leaves extract of Solenostemon monostachyus (lamiaceae) on cardiovascular system of mammalians: blood pressure lowering effects. Int J Pharm Bio Sci 2012;2(3):310-320. | Read article |

[9] Jacques DY, Fidele K, Michel OA. Acute toxicity and antioxidant activity of hydroethanolic extract of Solenostemon monostachyus P. Beauv. leaves. J Compl Integ Med 2010;7(1).

[10] Onu UO. Some pharmacological properties Solenostemon monostachyus. J Herbs Spices Med Plants 1996;4(2):3-7.

[11] Mve-Mba CE, Menut C, Lamaty G, Zollo PHA, Tchoumbougnang F, Bessiere JM. Aromatic plants of tropical central Africa. Part XIX. Volatile components from leaves of two lamiaceae from Cameroon: Leucas deflexa hook and Solenostemon monostachyus (P.Beauv.) Briq. Flavour Fragrance J 1994;9(6):315-317.

Online Resources:

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