Vicoa

They are annual or perennial herbs,[2] with simple (undivided or unsegmented),[3] or entire (not divided) leaves.[2] The leaves are arranged alternate (at different levels along the stem),[2][3] with pinnately veining (lateral veins are arranged either side of the main vein) and they are mostly amplexicaule (the base is dilated and clasping the stem) at the base.[2] They have flowers which have solitary,[2] radiate heads (ray floret surrounding disc florets),[2][3] which are either axillary (beside a leaf joint) or leaf opposed.[2] They have a peduncle (flower stalk),[2] and involucral bracts which are inbricate (overlapping) in several rows.[3] The achenes (one-seeded indehiscent fruit) are subterete (partially circular in cross-section) with a pappus (a tuft or ring of hairs or scales borne above the ovary) of unequal bristles.[3]

There are about 14 accepted species;[1]

• Vicoa albertoregelia C.Winkl.
• Vicoa cernua Dalzell
• Vicoa chodzhakasiani (Kinzik.) Nabiev
• Vicoa discoidea (Nabiev) Kamelin
• Vicoa glanduligera Krasch.
• Vicoa indica (L.) DC.
• Vicoa krascheninnikovii Kamelin
• Vicoa lignea (Mesfin) D.Gut.Larr., Santos-Vicente, Anderb., E.Rico & M.M.Mart.Ort.
• Vicoa multicaulis (Boiss.) Benth. & Hook.f.
• Vicoa parietarioides Nevski
• Vicoa propinqua Nevski
• Vicoa rupicola Krasch.
• Vicoa varzobica (Kamelin & Kinzik.) Nabiev
• Vicoa vestita (Wall. ex DC.) Benth. ex Hook.f.

Some species are still to be accepted, such as Vicoa gokhalei from India.[4]

The genus name of Vicoa is in honour of Giambattista Vico (1668–1744), an Italian philosopher, rhetorician, historian, and jurist during the Italian Enlightenment.[5] It was first described and published in Ann. Sci. Nat. (Paris) Vol.17 on page 418 in 1829.[1]

It was then absorbed into the genus of Pentanema, until in 2018, the Vicoa genus was re-established due to molecular analysis of the Pentanema genus.[6]

It is native to parts of Africa and Asia. From the island of Cape Verde, (Macaronesia), then the African countries of; Angola, Benin, Burkina Faso, Central African Republic, Chad, Eritrea, Ethiopia, Guinea-Bissau, Ivory Coast, Malawi, Mali, Mauritania, Mozambique, Senegal, Somalia, Sudan, Tanzania, Togo, Uganda, Zambia and Zimbabwe. Parts of Western Asia; Afghanistan and Iran. Central Asia; Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan and Uzbekistan. China; south-central and southeast China and Tibet. Indian subcontinent; East Himalaya, India, Nepal, Pakistan, Sri Lanka and West Himalaya. Lastly, parts of Indochina; Myanmar, Thailand and Vietnam.[1]

Some species such as Vicoa indica have used in folk medicine, in the Himalayas.[2][7][8] The roots were used to treat kidney troubles and the leaves were used for stomach problems.[9]