✵The TCM herbalism is also known as pharmaceutics of Traditional Chinese Medicine, or Chinese pharmaceutics, is the branch of health science dealing with the preparation, dispensing, and proper utilization of Chinese herbs. It is majorly composed of Introduction of Chinese Medicinals, Classification of Chinese Herbs, Formulas, and Patent medicines.
Classifications of Herbs:Herbs Clearing Heat and Drying Dampness.
Introduction: Herbs Clearing Heat and Drying Dampness: an agent or substance bitter in taste and cold in property that is effective for eliminating heat and dampness, usually used in the treatment of diseases caused by damp-heat, such as acute jaundice, acute dysentery, urinary infection, eczema, boils and abscesses.
✵Till the date Oct 10th,2019, there are totally  kinds of common TCM herbs,  kinds of related plant species, are recorded in this category. These Herbs Clearing Heat and Drying Dampness are briefly introduced separately:
Cortex Fraxini(Ash Bark).
Brief Introduction: The Herb Cortex Fraxini is the dried branch bark or trunk bark of Fraxinus rhynchophylla Hance, Fraxinus chinensis Roxb., or Fraxinus stylosa Lingelsh.(family Oleaceae), used for treating acute dysentery and inflammation of the eye. The herb is commonly known as Cortex Fraxini, Ash Bark, Qín Pí.
✵The herb Cortex Fraxini(Ash Bark) is the dried cortex or tree bark of species (1). Fraxinus rhynchophylla Hance., (2). Fraxinus szaboana Lingelsh., (3). Fraxinus chinensis Roxb., or (4). Fraxinus stuylosa Lingelsh., they are plants of the Fraxinus L. genus, the Oleaceae family of the Contortae order. These 4 commonly used species are introduced as:
(1).Fraxinus rhynchophylla Hance.: It is commonly known as F.Chinensis Roxb.var.rhynchopylla(Hance)Hemsl., or Dà Yè Chén, Hua Qu Liu, or Big Leaf Ash. Large deciduous trees, 12~15 meters tall. Bark grayish brown, smooth, lobed when old. Winter buds broadly ovate. Apex pointed, dark brown. Glossy, insides densely covered with brown fleecy fluff. Branch light yellow, straight, glabrous, last year branch dark brown, lenticels. Leaf axis masks shallow groove, lobular apex with joints, sometimes on nodes. Clusters of brown fleecy pubescence; 5~7 lobules, leathery, broadly ovate, obovate, or ovoid lanceolate, 3~11 cm long, 2~6 cm wide, vegetative branches lobule is wider, lobules significantly greater than the lateral, below 1 to the minimum, apex acuminate, flash point, or the tail, base obtuse, leaf irregular coarsely serrate, tooth slightly bend inward, sometimes waves, usually lower nearly entire, white pilose on along the vein axils, gradually bald net. Panicles terminal or axillary at annual shoot tip, ca. 10 cm long; Bracts lanceolate, ca. 5 mm long, caducous; Pedicels ca. 5 mm; Male flowers and hermaphroditic flowers; Calyx shallow cup-shaped, ca. 1 mm long, sepals triangular glabrous; No crown; Bisexual flowers with 2 stamens, ca. 4 mm; Pistil with short style, stigma 2-forked deeply lobed; Male calyx small, filaments fine, up to 3 mm; Samara linear, apex nut ca. 1 cm long, slightly raised; With persistent calyx. Its flowering period is from April to May, fruiting from September to October.
Ecological environment: It grows on slopes, river banks and roadsides below an elevation of 1,500 meters. It is a light-loving tree species, suitable for deep fertile and good water conditions on the soil. The root system is developed and has strong cold resistance, and can adapt to a wide range of temperature. The annual average temperature is 5.5~14.4 ℃, the extreme maximum temperature is 47.6 ℃ in July, and the extreme minimum temperature is over -40 ℃ in January. But the ability to withstand atmospheric drought is poor. When the relative humidity is about 45% in July-August and the temperature is above 38 ℃, the leaves will turn yellow or even fall off. It can still grow in soil when its salt content is less than 0.5%.
Distribution range: The tree is distributed in north China and the Yellow River basin provinces. In China, it mainly grows in the north and south of Tianshan mountain in Xinjiang. It grows well in Yili and the southern margin of junggar basin and Urumqi in the north and is also widely cultivated. It also grows in Hami and Turpan in the east and korla, aksu, kashgar and hotan in the Tarim basin in the south.
Trait identification: Branchlets reeled or grooved, 10~60 cm long, 1.5~3 mm. The outer surface is gray-white, gray-brown to black-brown or alternate with porphyry, flat or slightly rough, and there are gray-white circular lenticels and fine oblique wrinkles, some with branch marks; Inner surface yellow-white or brown, smooth. Hard and brittle, cross-section fibrous, yellow and white. No smell, bitter taste. The dry skin is long strips, 3~6 mm thick. The outer surface is grayish brown, with reddish-brown round or long lenticels and cracks. The quality is hard, the section fiber is stronger.
(2).Fraxinus szaboana Lingelsh.: It is commonly known as F. ChinensisRoxb.var.acuminata Lingelsh.; F.caudata J.L.Wu; F.Rhynchophylla Hance var.huashanensis J.L.Wuet Z．W．Xie., or Jiān Yè Chén, or Sharp Leaf Ash. Small deciduous trees, 3~8 meters high; Bark gray. Winter bud is big, aciculate conical, the outer side is close with yellow-brown fuzz and white glandular hair, inside is close with brown fleecy pilose. Branchlets yellow, glabrous or finely pilose, spinescent, lenticels small and prominent, brown, elliptic, scattered. Pinnately compound leaves 12~20 cm long; Petiole 3~5 cm long, base slightly enlarged, tufts of brown fleecy pilose when tender, soon shed; Leaf axis relatively thin, slightly curved, upper mask narrow groove, groove edge is deep, lobular apex is articular, by fine pilose; 3~7 lobulars, hard paper, lanceolate, oval thin egg shape lanceolate, 4.5~9 cm long and 2~4 cm wide, apical lobule is usually larger, apex long acuminate to acute, base cuneate to obtuse, margin with sharp blade, glabrous above, below and on each side of midrib base is sometimes pale yellow or white pilose, midrib above recess, lateral veins 6~8 pairs, flat above, the following bump, fine veins bulge grid junction; Petiole 2~3 mm long or subsessile. Panicle terminal or axillary shoot, 5~8 cm long; Peduncle 1.5~2 cm long, sometimes branched base with leaflike bracts, pilose or chrose-hairy, lenticels scattered, inconspicuous; Male flower and bisexual flower different plant; Calyx cup-shaped, ca. 1.5 mm long, calyx teeth triangular apex; No crown; Style shorter, stigma 2-branched. Samara spatulate, 3~3.5 cm long, ca.5 mm wide, middle-upper widest, apex obtuse, base tapering, lower wing reaching the middle of nut, nut ca. 1.2 cm long, raised, veins slender straight; Calyx teeth of persistent calyx orderly, distanced from the base of the nut. Its flowering period is from April to May, fruiting from July to September.
This species is distinct from Fraxinus rhynchophylla Hance.: branchlets, axles, and leaflets covered with hairs. 3~7 leaflets, leaflet apex long acuminate to caudate apex, often white pilose below midvein base. Flowers without corolla, open at the same time as leaves; Calyx cup-shaped, distanced from the base of the nut.
Ecological environment: This species grows in mountains areas with altitude above 1,000 meters above sea level. It is produced in the Yellow River, the Yangtze River valley provinces. The type specimens were collected from Hubei province.
(3).Fraxinus chinensis Roxb.: It is commonly known as F.Chinensis Roxb.Var.rotundata Lingelsh., or Bái Là Shù, or White-Wax Ash. Small deciduous trees, about 15 meters tall. The bark is smooth gray and lobed with age. Leaves opposite. Leaves odd-feathered, 3~7 leaflets, broadly ovate, long ovate or obovate, 4~12 cm long, 3.5~7 cm wide; Apical central lobules especially broad, base cuneate, trailing winglike or united with petiole, apex acute, margin shallowly coarsely obtusely serrate, abaxially veins brownish pilose, petiole opposite swollen, yellowish-brown pilose. Flowers white, terminal panicle, 4 calyxes, corolla not present, 2 stamens, ovary superior, 2 locules. Samara oblanceolate, containing 1 seed.
Different from the former two species: lobules are ovate, obovate-oblong to lanceolate, apex acute to acuminate; Calyx tubular, appressed to nut base.
Ecological environment: This species grows in the slope of the sun, broad leaf forest, river wetland. It is produced in north China or the Yangtze river basin provinces, southwest China.
(4).Fraxinus stuylosa Lingelsh.: It is commonly known as F.Jallax Lingelsh., or Sù Zhù Chén. Small deciduous trees, about 8 meters high, branches sparse; Bark grayish brown, longitudinally lobed. Buds ovate, dark brown, shiny when dry, sometimes varnished.
Branchlets pale yellow, straight and smooth, nodes enlarged, glabrous, lenticels sparsely convex. Pinnately compound leaves 6~15 cm long; Petiole slender, 2~5 cm long; Leaf axis thin and straight, upper mask narrow groove, leaflets inserted with joints, base thickened, glabrous; Lobular 3~5 pieces, hard paper, ovoid lanceolate to broadly lanceolate, 3.5~8 cm long, 0.8~2 cm wide, apex long acuminate, base broadly cuneate, next to short shank, sometimes obtuse, margin finely toothed, glabrous or sometimes white pilose on veins on the below, midrib above recess, raised below, lateral veins 8~10 on, fine veins effect is not obvious; Petiole 2~3 mm long, glabrous.
Panicles terminal or axillary annual branch tips, 8~10 (~14) cm long, branches slender, loose; Peduncle flat, glabrous, more lenticels, especially evident fruit; Pedicels slender, ca. 3 mm long; Calyx cup-shaped, ca. 1 mm long, 4 calyx teeth, narrowly triangular, acute, equal to calyx tube; Corolla yellowish, lobes linear-lanceolate, ca. 2 mm long, ca. 1 mm wide, apex obtuse; Male flowers with 2 stamens, slightly longer than corolla lobes, anthers oblong, filaments slender; Female flower not seen. Samara oblong-lanceolate, 1.5~3.5 cm long, 2.5~5 mm wide, widest in upper-middle, apex acute, obtuse or concave, with a small apex (persistent style), lower wing reaching above the middle nut, nut protuberant. It is flowering in May, fruiting in September.
The difference between this species and other three species is that the leaflets are sessile or nearly sessile, the leaves are ovate-lanceolate to lanceolate, and the leaf axis is thin and straight. Flowers corolla, first leaf, then flower; Calyx teeth prominent.
Ecological environment: This species grows in mountainside mixed wood forest, elevation 1,300-3,200 meters. Produced in northwest and southwest, middle area of the Yellow River.