Phytolacca acinosa

Phytolacca acinosa Roxb. (incl.: P. esculenta Van Houtte) (E-As.) – An increasing, locally naturalised garden escape. First recorded in 1960 on a talus slope of the Albertkanaal in Kanne. From 1990 onwards seen as an urban weed in many cities: Antwerpen, Brugge, Brussel, Gent, Izegem, Kortrijk, Leuven, Liège, Menen, Tielt, Tongeren and doubtlessly elsewhere. Phytolacca acinosa most often occurs in gardens or parks (under trees or shrubs, foot of walls,…), in cemeteries or in urban wasteland. It produces berry-like fruits that are frequently eaten by birds and most populations are obviously birdsown. Phytolacca acinosa often occurs in single specimens but more or less luxuruous populations are increasingly recorded. It may be considered by now as fully naturalised and future invasive behaviour cannot be excluded.

Herbarium specimen

A leaf of Phytolacca acinosa Fruits of Phytolacca acinosa

Phytolacca acinosa is considered here in a broad sense as to include all eastern Asian related taxa that are cultivated for ornament (P. esculenta and P. latbenia (Buch.-Ham.) H. Walter). The distinction of these taxa is critical and diagnostic features often overlap. Clement (1982, 1998) provides an identification key that includes all minor taxa of Phytolacca in cultivation (and as escapes) in the British Isles. The Belgian collections of the Phytolacca acinosa group are usually more or less intermediate between P. acinosa and P. esculenta: inflorescence axes are often scabrid-glandular (like in P. acinosa) but floral characters more resemble P. esculenta. Phytolacca latbenia (with 10-16 stamens instead of 7-9) is perhaps more distinct and has also been claimed as an escape in Belgium. Recent taxonomists tend to include these minor taxa in a broadly circumscribed Phytolacca acinosa (see for instance Ghosh & Sikdar 1983, Dequan & Larsen 2003).

Another Asian species, Phytolacca polyandra Batalin (syn.: P. clavigera W.W. Smith), is locally naturalised in the British Isles (Clement & Foster 1994). It is probably more closely related to Phytolacca americana (both share the basally connate carpels) but otherwise much resembles P. acinosa in general appearance. It might have been overlooked or possibly should be included in the synonymy of Phytolacca acinosa as well (see for instance van der Meijden 2005).

Phytolacca acinosa is often confused with P. americana in Belgium. In fact many records of the latter doubtlessly belong to Phytolacca acinosa, by far the commonest representative of the genus in Belgium. Phytolacca acinosa always is a much smaller plant (rarely exceeding 100 cm) with an erect inflorescence and broader leaves. Moreover, at least in Belgium, it starts flowering much earlier: Phytolacca acinosa starts flowering from May onwards whereas Phytolacca americana does not flower before July.

Phytolacca acinosa, Tielt, plantation weed, June 2009, F. Verloove

Phytolacca acinosa, Tielt, plantation weed, June 2009, F. Verloove

Selected literature

Adolphi K. (1995) Neophytische Kultur- und Anbaupflanzen als Kulturflüchtlinge des Rheinlandes. Nardus 2: 272 p.

Balogh L. (2005) Phytolacca esculenta Van Houtte Magyarországon. Flora Pannonica 3: 135-161.

Clement E.J. (1982) Pokeweeds (Phytolacca ssp.) in Britain. BSBI News 32: 22-23.

Clement E.J. (1998) Phytolacca. In: Rich T.C.G. & Jermy A.C. (eds.), Plant crib: 79. BSBI, London.

Clement E.J. & Foster M.C. (1994) Alien plants of the British Isles. BSBI, London: XVIII + 590 p.

Dequan L. & Larsen K. (2003) Phytolaccaceae. In: Wu Z.Y. & al. (eds.), Flora of China, vol. 5. Science Press, Beijing & Missouri Botanical Garden Press, St. Louis: 435-436.

Dieu J.-M., Lambinon J. & Rousselle J. (1997) Quatre adventices sur les trottoirs de la ville de Liège: Catapodium marinum, Diplotaxis muralis, Elsholtzia ciliata et Phytolacca esculenta. Nat. Mosana 50(1): 17-18.

Ghosh R.B. & Sikdar J.K. (1983) A revision of the Indian Phytolaccaceae (sensu lato). J. Econ. Taxon. Bot. 4(1): 153-163.

Skalický V. (1972) Lícidlo jedlé (Phytolacca esculenta van Houtte), nový zplanĕlý druh kvĕteny ČSSR a NDR a rozšíření druhů Phytolacca esculenta van Houtte a P.americana L. v ČSSR. Preslia 44(4): 364-369.

Terpo A. & Balint K.E. (1985) A `karmazsinbogyo' (Phytolacca) fajok kiwadulasa es a Ph. americana meghonosodasa Magyarorszagon. Bot. Közlem. 72(1-2): 127-139.

Van der Meijden R. (2005) Heukels’ Flora van Nederland (23e druk). Wolters-Noordhoff, Groningen: 685 p.

Verloove F. (2002) Ingeburgerde plantensoorten in Vlaanderen. Mededeling van het Instituut voor Natuurbehoud n° 20: 227 p.

Verloove F.(2006) Phytolacca esculenta. In: Van Landuyt W., Hoste I., Vanhecke L., Van den Bremt P., Vercruysse W. & De Beer D., Atlas van de flora van Vlaanderen en het Brussels gewest. Instituut voor Natuur- en Bosonderzoek, Nationale Plantentuin van België en Flo.Wer: 666.

Wyrzykiewicz-Raszewska M. (2009) Phytolacca acinosa Roxb. – a new anthropophyte in the flora of Poland. Steciana 13: 3-7. [available online at:]

Zieliński J., Petrova A. & Natcheva R. (2012) New species for the Bulgarian flora. Phytol. Balcanica 18(2): 197-204. [available online at:]

Scratchpads developed and conceived by (alphabetical): Ed Baker, Katherine Bouton Alice Heaton Dimitris Koureas, Laurence Livermore, Dave Roberts, Simon Rycroft, Ben Scott, Vince Smith