A collaboration of coast and countryside organisations on The Lizard Peninsula

With its long flowering period (May to early autumn) and beautiful scent when crushed, Pineappleweed is a common find by paths, on wasteland and in arable grass on the Lizard.
Photo: Steve Townsend

PINEAPPLEWEED

Scientific name: Matricaria discoidea

Other common names: Pineapple Mayweed, Disc Mayweed

Conservation status: No designations

Pineappleweed is a common and widespread plant, often found on paths and as a coloniser of wasteland, as well as being an arable weed. It is a curious looking plant, rather like a chamomile but with no white ‘petals’.

However, Pineappleweed belongs to the Daisy family (Asteraceae), one of the most advanced families, from an evolutionary perspective, of flowering plants. Each ‘flower’ of a plant in Asteraceae is in fact made up of many small flowers – or inflorescences – which are of two types: either tube-like and clustered in a central disc (the disc florets), or having the superficial appearance of petals round this disc (the ray florets). Many Daisy family flowerheads have both disc and ray florets, but not all do. This is the reason for the appearance of Pineappleweed: it is simply that it possesses no ray florets, but its cone-shaped head is still crammed with greeny-yellow disc florets.

This annual plant has another very distinguishing feature, which is given away by its name: crush it, and it has a very strong scent of pineapple. An erect plant, to about 35 cm tall, its leaves are divided pinnately, and are very similar to Chamomile in appearance. The flowering period is long, from May to November.

It is not in fact native to Britain. Pineappleweed originated in Asia, and is also possibly native to parts of North America, from where it arrived here. It was first recorded in mainland Britain in 1871, as an escape from Kew Gardens. It owes its rapid spread since then to being transported with motor vehicles, from the pre-tarmac days when seed-carrying mud from roads could be carried by tyres for long distances (Mabey, 1997).

Did you know…?

…Pineappleweed is now distributed across the boreal and temperate zones in the northern hemisphere.

…It is used in herbal medicine as an anti-inflammatory, and for gynaecological disorders (its genus name Matricaria is derived from the Latin word for ‘uterus’).

More information and references:

Mabey, R., 1997. Flora Britannica. Chatto & Windus, London.

Rose, F. and O’Reilly, C., 2006. The Wild Flower Key, 2nd edition. Frederick Warne, London.

Stace, C., 2010. New Flora of the British Isles, 3rd edition. Cambridge University Press, Cambridge.

Websites:

Online Atlas of the British and Irish Flora: http://www.brc.ac.uk/plantatlas/index.php?q=plant/matricaria-discoidea

 

Published: September 2013
Author: Amanda Scott
Photos: Steve Townsend

Click here for information about other plant species found on the Lizard.