Calendula
officinalis L.
Standardized Common
Name: Calendula
Other Common Names: Marigold, Pot
Marigold
Family: Asteraceae
(Compositae)
Taxonomy: Calendula includes about a dozen species, mostly Mediterranean or
Southwest Asian. Calendula officinalis is native to Europe and western
Asia, and is widely cultivated.
Description: Annual herb, 40–60
cm high. Leaves alternate, (3–)7–14(–17) cm long, oblanceolate to obovate,
thick, pubescent; base spatulate or tapering; apex acute to obtuse; margins
entire to serrate. Inflorescence a single terminal head, 4–7 cm across.
Involucre 1.5–2 cm across, with 2 rows of bracts (phyllaries); phyllaries 8–15
mm long, to 2 mm wide, lanceolate, curved, acute, tough, pubescent, dark
greyish-green with light brown margins. Receptacle flat, bearing 2–3 rows of
ray florets and numerous disk florets. Ray florets female, yellow to orange;
tube to 2 mm long, pubescent with long hairs; ligule 1.5–2.5(–3.5) cm long, 3–7
mm broad, oblanceolate, 4–5-veined, (1–)3(–4)-dentate with small teeth,
glabrous. Disk florets perfect, <5 mm long; corollas orange-yellow to
brownish, funnelform; tube sparsely pubescent at base; teeth 5, spreading,
pointed; corolla easily separated from ovary. Achenes without pappus, 1–2 mm
thick, tapering or sometimes beaked at base and apex; dorsal surface dark
brownish-green, pubescent with 2–3 rows of minute spiny bumps, often with pale
lateral wings; ventral surface paler, glabrous.
Parts
in Commerce:
Ligulate florets
Identification: Identification of
composites is easier when the entire head is available for examination. The
ligulate florets are frequently sold stripped from the heads, so that
relatively few characters remain, and fruits should be rare. Features to note
in the ray florets include:
- Yellow to
orange, glabrous
- Tube <2 mm
long, hairy, enclosing style and bifid stigma
- Ligule 1.5–3.5
cm long, 3–7 mm broad
- Ligule apex
usually with 3 small pointed teeth
- Main veins
4(–5), central 2 running to notches between teeth; veins faint, lesser
veins may be present between main veins
- No pappus
present
- Immature achene
curved, 1–2 mm thick, often winged
- Dorsal side of
achene darker, pubescent, with rows of small spiny bumps; ventral side
paler, glabrous and without bumps
- Taste weak,
slightly bitter or salty
Some
disk florets are expected to be present among harvested ligulate florets; these
are small, yellow to orange, reddish-purple or brownish, with a narrowly
funnelform tube and 5 lobes. Phyllaries, if present, should be narrowly
lanceolate to nearly linear, 8–15 mm long, stiff and pubescent.
References:
Meikle RD. Calendula. In: Tutin TG, Heywood VH, Burges NA, et al.,
eds. Flora Europaea. Vol. 4. Cambridge: Cambridge University
Press; 1976:206–207.
Wichtl M, ed. Herbal Drugs and
Phytopharmaceuticals, 3rd English
ed. Stuttgart: medpharm Scientific Publishers and Boca Raton, FL: CRC Press;
2004:100–103.
World Health
Organization. WHO Monographs on Selected Medicinal Plants. Vol. 2. Geneva: World Health Organization;
1999–2002:35–44.
Youngken HW. Text-Book of Pharmacognosy, 5th ed. Philadelphia, PA: The
Blakiston Company; 1943:874–875.
Figure 14: a–d, Calendula
officinalis involucre, ray floret base, ray floret corolla and disk floret.
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