MEDICAL BOTANY - A.G. Serbin - 2003

SECTION 3. SYSTEMATICS

SUPERKINGDOM EUCARYOTA — EUCARYOTA. KINGDOM PLANTAE

CLASS DICOTYLEDONES — Dicotyledones

SYSTEM OF FLOWERING PLANTS PROPOSED BY A.L. TAKHTAJIAN (1987)

Subclass Hamamelididae — Hamamelididae

Family Urticaceae — Urticaceae

Stinging nettle — Urtica dioica (Fig. 3.15). A perennial dioecious herb distributed everywhere as a weed. Rhizome long, creeping.

Stems erect, four-sided, with closed nodes, covered with long stinging hairs (Fig. 3.15,1). Leaves decussately opposite, long-petiolate, stipulate. Leaf blade thin, dark green, oblong-ovate or cordate, acuminate, with a coarsely serrate margin and a network of pinnate Veins prominent on the lower surface. The epidermis contains lithocyst Cells enclosing cystoliths (Fig. 3.15,2), which are clusters of calcium carbonate crystals. Flowers small, forming axillary unisexual racemose thyrrses exceeding the petiole in length. Perianth segments and stigma persist in fruit.

Class="center">Fig. 3.15. Urtica dioica

Flower formulas:

Fruits are ovoid, compressed nutlets about 1 mm long, enclosed in 4 greenish perianth lobes, of which the 2 inner ones are larger than the outer and cover the fruit. Surface matte, light gray in color.

The herb and leaves are used as a hemostatic, wound-healing, and multivitamin agent, as well as for rheumatism, diabetes, Skin conditions, Hair loss, and Metabolic Disorders.

Family Fagaceae — Fagaceae

English oak, or common oak — Quercus robur (Fig. 3.16). Grows in Europe, North America, Western Asia, the Crimea, and the Caucasus. A monoecious tree up to 50 m tall, growing sympodially. Leaves alternate, short-petiolate, oblong-obovate, pinnately lobed, lobes unequal, obtuse, entire. Leaves unfold either during flowering (in April) and fall off for the winter, or in May and remain dry through the winter (durmast oak). Mature leaves pubescent below. Male flowers gathered in long axillary racemose thyrrses. Female flowers sit 2–5 in the axils of upper leaves, surrounded by a broad cup-shaped involucre of leaf-like outgrowths, which turns into a saucer-shaped cupule in fruit.

Flower formulas:

Fruit is an oblong-barrel-shaped acorn 2–3.5 cm long, brownish-brown with longitudinal stripes, with a cup-shaped cupule at the base and a small spine at the apex. Cupule scales woody, short, tightly appressed, grayish-tomentose. Pedicel longer than the petiole (6–8 cm).

Uses: wood in the national economy; acorns as fodder and as a dietary coffee substitute; bark of young shoots as an astringent and anti-inflammatory agent; old bark for leather tanning.

Fig. 3.16. Quercus robur

Family Betulaceae — Betulaceae

Silver birch, or weeping birch — Betula verrucosa (B. pendula) (Fig. 3.17). Grows in gardens and parks, planted as shelterbelts and windbreaks, and for slope stabilization. A monoecious, frost-hardy tree up to 20 m tall, living up to 150 years. Trunk covered with smooth white bark — birch bark with horizontally elongated lenticels. It easily peels off in thin layers. Shoots slightly pendulous, reddish-brown, glabrous, with glandular-warty lenticels, bearing vegetative, generative, and mixed buds. Leaves alternate, simple, petiolate, rounded-rhombic, acuminate, with an irregularly doubly serrate margin. Young leaves bright green, shiny, and sticky due to resinous wart-like glands. Blooms simultaneously with leaf unfolding. Male flowers on short pedicels, arranged in groups of 3 in a dichasial pattern in the axils of reddish-brown bracts, forming long catkins at the ends of branches. Perianth simple, 1–2-leaved, stamens forked.

Fig. 3.17. Betula verrucosa

Floral formula:

Pistillate flowers lack a perianth and possess two bracts fused with a three-lobed cover scale. They are gathered in clusters of 5 within dichasia on shortened lateral shoots, forming short, cylindrical, green catkins. The pistil features a two-celled inferior Ovary and two filiform stigmas.

Floral formula:

The fruit is a flatly compressed, oblong-elliptic nut equipped with two broad membranous wings.

The birch bark and wood are utilized as industrial raw Materials and for producing activated carbon and tar. The buds and leaves serve as diuretic, cholagogue, and expectorant agents. They are employed in treating rheumatism, myositis, wounds, and for strengthening hair. Birch sap is recommended for Bronchitis, furunculosis, Gout, eczema, and lichen. Betulin found in the bark exhibits antiseptic properties.