NIS - libdoc.who.int - World Health Organization

Folium cum Flore Crataegi
the cells along the veins. Epidermis of floral pedicel and receptacle contain
abundant covering trichomes similar to those on the leaf, but longer
and more undulating; calyx with numerous anomocytic stomata on the
outer epidermis, inner epidermis with a striated cuticle; epidermal cells of
corolla distinctly papillose; fibrous layer of anther with characteristic
thickenings; pollen grains spherical to elliptical, up to 45 µm in diameter,
with 3 germinal pores and faintly granular exine. Epidermal cells of stem
have thickened anticlinal outer walls; cortex parenchymatous with prismatic
and cluster crystals of calcium oxalate; dense groups of small, tightly
packed pericyclic fibres with much thickened and lignified walls; xylem
completely lignified, composed of scattered vessels, thick-walled fibres
and parenchyma separated by distinct medullary rays containing browncoloured
matter; larger vessels with bordered pits, smaller elements with
annular or spiral thickening; central pith parenchymatous and lignified,
cells with moderately thickened walls and numerous pits (12, 15).
Powdered plant material
Yellowish-green. Unicellular covering trichomes, usually with a thick
wall and wide lumen, almost straight or slightly curved, pitted at the base;
fragments of leaf epidermis with cells which have sinuous to polygonal
anticlinal walls and large anomocytic stomata surrounded by 4–7 subsidiary
cells; parenchymatous cells of mesophyll containing cluster crystals
of calcium oxalate, usually 10–20 µm in diameter; cells associated with
veins contain groups of small prismatic crystals. Petal fragments showing
rounded polygonal epidermal cells, strongly papillose, thick walls with
clearly visible wavy striations in the cuticle; anther fragments showing
endothecium with an arched and regularly thickened margin. Stem fragments
containing collenchymatous cells, bordered, pitted vessels and
groups of lignified sclerenchymatous fibres with narrow lumina. Numerous
spherical to elliptical or triangular pollen grains up to 45 µm in diameter,
with 3 germinal pores and a faintly granular exine (1).
General identity tests
Macroscopic and microscopic examinations, thin-layer chromatography
(1, 7), and microchemical test for the presence of procyanidins (7).
Purity tests
Microbiological
Tests for specific microorganisms and microbial contamination limits are
as described in the WHO guidelines on quality control methods for medicinal
plants (16).
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