Chamaemelum nobile

Status Disc florets UK Biodiversity Action Plan Priority species. IUCN threat category: Vulnerable (2005). Ray florets Taxonomy Magnoliopsida: Asteraceae Scientific name: Chamaemelum nobile (L.) All. Receptacle Common names: Chamomile, Camri.

Chamaemelum nobile (Anthemis nobilis L.) is one of the superficially similar group of plants often referred to as Mayweeds. Mayweeds usually have leaves divided into narrow segments and daisy-like heads with yellow disc florets in the centres and white ray florets outside (Figure 1).

Chamaemelum nobile itself is not a variable species in the wild, though some populations are distinctive (Kay & John 1994) and there are many cultivars (the Leaves aromatic, latter rarely escape or persist in the wild). Once finely divided, known, it is easily recognised, but the distinctive and hairy well-known aroma of crushed leaves is similar to some Anthemis species. No hybrids are known.

Biology & Distribution Rooting Chamaemelum nobile is predominantly recorded at nodes in SW and SE England and SW Ireland, and is Figure 1. Chamaemelum nobile (from J. E. Smith & J. Sowerby rare or extinct in Wales and central England. It is (1852). English Botany. London). occasionally introduced elsewhere (Preston et al. 2002). It is characteristic of seasonally-inundated turf, heathland, grassland, sports fields and grassy sea Key characters Procumbent, hairy, perennial herb rooting at the cliffs, especially where grazing or mowing keeps the nodes and often forming patches. Pleasantly aromatic vegetation short and open (Winship 1994). when rubbed. Leaves finely divided. Flowering Identification & Field survey heads 18-25 mm across, solitary, on long stalks. Ray florets white, spreading (rarely absent), disc florets It is easiest to identify Chamaemelum from other yellow. Receptacle scales oblong, concave, blunt. Mayweeds in flower, but with practice this can also Seed narrowed and rounded at top, enveloped by be done from the leaves and shoots alone. Keys to tube at top all Mayweed species are given in Wilson (1994) and Philp et al. (1998).

An important character is the presence of small, Lobe membranous scales on the receptacle at the base of Tube each floret in the flowering heads (Figure 2b). These scales are about ⅔ the length of the florets and are Seed hidden by them, but can be easily seen when present b c a (as in Chamaemelum and Anthemis) by plucking out the disc florets with finger-nails to leave the scales on the receptacle. A diagnostic character is that the base of the tube of the disc florets extends down and Figure 2. a Flowering head. b Disc floret and envelopes the top of the developing seed (Figure 2b). receptacular scale. c Seed Differentiation from similar species

Key to flowering plants

1. Ray florets absent; erect annual Matricaria discoidea 1. Ray florets yellow Anthemis tinctoria 1. Ray florets white 2

2. Small membranous scales present on the receptacle hidden under the disc florets (Figure 2b) 3 2. No scales present on the receptacle Matricaria and Tripleurospermum spp.

3. Procumbent perennial; tube of disk florets not flattened or winged (Figure 2b); seeds ribbed only on one face, rounded above (Figure 2c) Chamaemelum nobile 3. Erect annuals; tube of disk florets flattened and somewhat winged below; seeds ribbed on both faces, squarish above Anthemis spp.

Key to vegetative plants

1. Plants scentless or nearly so (rub fresh leaves between fingers, avoid touching eyes afterwards!) Tripleurospermum 1. Plants obviously scented 2

2. Glabrous except for hair points on leaf tips Matricaria 2. Hairy on leaves and stems 3

3. Prostrate perennial, rooting from lower leaf axils (Figure 1) Chamaemelum nobile 3. Erect, not rooting at nodes Anthemis

References Kay, Q. O. N. & John, R. F. (1994). Population Winship, H. R. (1994). Chamomile - the herb of genetics and demographic ecology of some humility in demise. British Wildlife 5(3): 163-165. scarce and declining vascular plants of Welsh Additional photographs are available on the ARKive lowland grassland and related habitats. website (http://www.arkive.org/species). Countryside Council for Wales Science Report No. 93. March 1994. Philp, E. G., Kay, Q. O. N., Wilson, P. J. & Rich, T. C. G. (1998). Chamaemelum / Anthemis / Matricaria / Tripleurospermum, Mayweeds. pages 305-306 In Rich, T. C. G. & Jermy, A. C., eds. (1998). Plant Crib 1998. BSBI, London. Plantlife (2001). Managing your land for Chamomile. Back from the brink management series. Plantlife, London. (www.plantlife.org.uk). Preston, C.D., Pearman, D. A. & Dines, T. D. eds. (2002). New Atlas of the British & Irish flora. Oxford University Press, Oxford. Wilson, P. J. (1994). British mayweeds. British Wildlife 5(3): 158-162.