Chamaemelum
nobile (L.) All.
Standardized Common
Name: Roman
Chamomile
Other Common Names: Common Chamomile,
English Chamomile, Garden Chamomile
Family: Asteraceae
(Compositae)
Taxonomy: Chamaemelum
includes six mostly Mediterranean species that are closely related to Anthemis,
a much larger genus with a broader range. The basionym of C. nobile is Anthemis nobilis L., and several wild
species commonly known as chamomiles are still placed within the genus Anthemis.
Description: Perennial herb.
Stems numerous, prostrate or ascending, branching, (5–)10–30 cm high. Leaves
alternate, sessile, 2–5 cm long, oblong, deeply 2–3-pinnatisect; lobes
numerous, crowded, linear, mucronulate, pubescent. Heads few, terminal, with
long pubescent peduncles, 1.2–3 cm in diameter; in wild material, ray florets
12–20 or rarely absent, disk florets numerous; in cultivated material, most or
all florets ligulate. Involucre hemispherical, 4–9 mm in diameter; involucral
bracts (phyllaries) 4–6 mm long, in 2–3 rows, oblong to obovate, blunt, with
scarious transparent borders and green midrib, slightly hairy. Receptacle
conical, solid, with receptacular bracts (paleae) subtending flowers; paleae
slightly shorter than disk florets (to ca. 3 mm), sometimes curving around
florets, with blunt apex, scarious, bearing minute hairs. Ray florets female;
corollas white, contracted into a tube at the base; ligules strap-shaped to
ovate-oblong, 7–10 mm long with 3 inconspicuous apical teeth, usually 4-veined
(rarely 3–6-veined). Disk florets bisexual, small; corolla yellow, tubular
below, somewhat dilated at base, upper part campanulate and five-lobed. Achenes
without pappus, ca. 1 mm long, smooth, pale greenish brown, with persistent
corolla base at apex; with 3 faint ribs, 1 adaxial and 2 lateral.
Parts
in Commerce:
Heads
Identification: Commercially
cultivated C. nobile is always more
or less doubled (with some disk florets converted to ray florets); “single
chamomile” usually refers not to the wild type but to those plants which still
have a significant number of ray florets, as opposed to “double chamomile” in
which nearly all florets are ligulate. Aromatic compounds are said to be more
concentrated in the disk florets, so the preference for doubled flowers must be
aesthetically rather than pharmacologically motivated. Since similar-looking
wild contaminants will generally have only one whorl of ray florets, cultivated
C. nobile is easily identified. In
addition to the unusual appearance of the heads, whereby most or all florets
are ligulate and white or yellowish-white, its features include:
- 1.2–3
cm in diameter
- Receptacle
conical in longitudinal section (not flat or hemispherical), solid, with 2–3
rows of involucral bracts (phyllaries)
- Receptacular
bracts (paleae) chaffy, densely covering receptacle
- Odor
characteristic, aromatic
- Taste
aromatic, bitter
If
material of wild C. nobile is to be
identified, many more species are similar enough to represent possible
contaminants; smaller features should then be observed, such as the following:
- Corolla
tube of ray florets distended at base, narrowly tubular below, bell-shaped at
the top
- Achenes
<1 mm long, with three faint, widely spaced ribs (not with 4+ ribs or with
heavy ribs), crowned with persistent corolla base
- Pappus
absent
- Receptacular
bracts green to transparent, not with dark brown edges and apices, nor densely
woolly.
Adulterants: Cultivated C. nobile is easily distinguished from
most potential adulterants. Doubled heads of Tanacetum parthenium (L.) Sch. Bip. (Feverfew) are a reported
adulterant; these flowers can be distinguished by their flattened receptacle.
Doubled heads of feverfew sometimes have bracts on the receptacles, but they
are comparatively few in number, more acute, and less membranous than those of C. nobile. The achenes of the ray
florets also have a pappus in the form of a small corona. Flowers of Achillea ptarmica are also reported as
potential adulterants; these likewise lack a conical receptacle, and are less
than 12 mm in diameter.
Wild
C. nobile could be confused with
several plants, including species of Matricaria
and Anthemis (c.f. Matricaria
chamomilla L.) whose common names include “chamomile,” emphasizing
their close resemblance. Matricaria
is distinguished by its hollow receptacle. Anthemis,
while very similar to Chamaemelum,
lacks the swollen, persistent corolla base; in several common species, the
achenes are >1 mm long with more than 3 ribs, and may have a small corona.
Species of Tripleurospermum, closely
related to Matricaria, may be
distinguished by the presence of orange resin sacs on the lobes of the disk
corollas. Other species of Chamaemelum
have similar capitula, but have not been found as contaminants in commerce;
these differ mainly in the above-mentioned features of the receptacular bracts.
References:
Bremer K, Humphries CJ.
Generic monograph of the Asteraceae – Anthemidae. Bull Nat Hist Mus London (Bot). 1993;23:71–177.
Moore
DM, Tutin TG, Walters SM, eds. Compositae. In: Tutin TG, Heywood VH, Burges NA, et al., eds. Flora
Europaea. Vol. 4. Cambridge: Cambridge University Press; 1976:103–410.
Wichtl M, ed. Herbal Drugs and
Phytopharmaceuticals, 3rd English
ed. Stuttgart: medpharm Scientific Publishers and Boca Raton, FL: CRC Press;
2004:127–129.
Figure 18: a–b, Chamaemelum
nobile head.
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