Hamamelidis Folia. Br. Hamamelis Leaves.
[Hamamelis, U. S. 1890. Witchhazel Leaves]
Related entry: Hamamelis Bark
"Hamamelis Leaves are the fresh or dried leaves of Hamamelis virginiana, Linn." Br. "The dried leaves of Hamamelis virginiana Linne (Fam. Hamamelidaceae), collected in autumn before the flowering of the plants, and without the presence of more than 10 per cent. of stems or other foreign matter." N. F.
Hamamelidis Folia, N. F.; Feuilles de Hamamelis, Fr. Cod.; Witchhazel, Witch Hazel Leaves.
These leaves were deleted from the U. S. P. IX, but were retained in the British Pharm., 1914, and National Formulary IV.
The National Formulary IV added the following to the U. S. P. VIII definition: "Before the flowering of the plants and without the presence of more than 10 per cent. of stems or other foreign matter."
The British Pharm., 1914, describes the leaves as follows: "Broadly oval in outline, from seven to fifteen centimeters long. Upper surface dark green or brownish-green, under surface paler; apex obtuse, margin sinuate; narrowed towards the base, oblique, slightly cordate, and shortly petiolate. Veins pinnate and prominent on the under surface, where they are furnished with stellate hairs. No marked odor; taste astringent and slightly bitter." Br.
The N. F. IV description is as follows: "Petioles from 1 to 1.5 cm. in length; laminae when entire broadly elliptical or rhomboid-ovate, usually inequilateral, mostly from 8 to 12 cm. in length; summits usually acute, sometimes rounded or acuminate; bases slightly heart-shaped and oblique; margins sinuate or sinuate-dentate; upper surfaces pale or brownish-green, occasionally dark brown with a few stiff, straight hairs; lower surfaces lighter in color, somewhat hairy, midrib and veins prominent. Odor slight; taste astringent, slightly aromatic and bitter. Transverse sections show in addition to the epidermal layers, a palisade layer consisting of a single row of cells and a dorsal pneumatic tissue made up of three to six rows of strongly branching cells; large collateral, fibro-vascular bundles occur in the midrib and petiole, the tracheae narrow, mostly spiral and associated with numerous narrow, strongly lignified and porous wood fibers; around the phloem occurs a nearly continuous circle of bast fibers, possessing strongly lignified walls; calcium oxalate in mono-clinic prisms, from 0.01 to 0.035 mm. in diameter, either in the cells of the mesophyll or in crystal fibers associated with the bast fibers. Under the microscope, surface sections of Hamamelis Leaves show upon the lower surface narrow elliptical stomata, about 0.015 mm. in length and with two to four neighboring cells; from both surfaces, but especially from the under surface, arise stellate hairs composed of from four to twelve cells united at the base, the individual cells being from 0.02 to 0.075 mm. in length, either straight or more or less bent and with very thick walls and narrow lumina, the latter sometimes only apparent in the lower portion of the cells. Hamamelis Leaves yield not more than 6 per cent. of ash." N. F.
The microscopical characteristics of the hamamelis leaves have been described by Hans Kramer in B. P. G., xvii, p. 323.
Off. Prep.—Fluidextractum Hamamelidis Foliorum, N. F. (Br.); Liquor Hamamelidis, Br.; Unguentum Hamamelidis (from Liquid Extract), Br.
