1. Dioscorea pentaphylla
Botanical name: Dioscorea pentaphylla L., Sp. Pl.
Common name/ Local name: Five leaf yam/Noora kizhangu
Family: Dioscoreaceae
Description: A climber with underground tuber has seen in degraded deciduous forests and in sacred groves. The plant produces horseshoe-shaped bulbils about a centimeter long. Leaves 3-5-foliolate.The tubers of this plant are hairy, black outside, inner fleshy and white. New plants can sprout from the bulbils and found in degraded deciduous forests and also in sacred groves. Tubers are used as vegetable occasionally. The Flowering & fruiting has observed from August to November.
Significance: Edible and medicinal uses. The Root may consume on cooking. Male inflorescences and young leaves are consumable as well. The extract of the plant is traditionally used for boils and swellings.
2. Dioscorea hispida
Botanical name: Dioscorea hispida Dennst.
Common name/ Local name: Asiatic bitter yam/ Kottunoora
Family: Dioscoreaceae
Description: Climbing herb with a fibrous root system. The outline is globose, sometimes slightly elongated and pale yellow to light grey. Bulbils are absent, trifoliolate leaves, herbaceous and pubescent. Male inflorescence spike and female inflorescence is solitary. Fruit a large woody capsule, honey-colored, margin sometimes freed in dehiscence. Seed winged
Significance: The tuber is the chief famine food. The tuber is slightly toxic because of the high content of the alkaloid dioscorine. The toxin in the tubers is often extracted and used as bait for animals or other devious purposes. It is also used for eliminating fish from shrimp pond cultures. It’s consumption requires much time for detoxification and it includes slicing of yams and washing the fresh or boiled tubers several time in salt water or in running water.
3. Dioscorea hamiltonii
Botanical name: Dioscorea hamiltonii Hook.f., Fl. Brit. India
Local name: Kaluvenni
Family: Dioscoreaceae
Description: Dioscorea hamiltonii is mostly seen in semi-evergreen and moist deciduous forests .The Stem angled and glabrous with leaves ovate or lanceolate. Male inflorescence is slender axillary spikes and female inflorescence is spikes. Fruit is orbicular and glabrous with flowering and fruiting during October to December. The plant is distributed in Indo-Myanmar region.
Significance: It is edible and has medicinal properties. The root has to be cooked for consumption. It has been used for the treatment of stomach ache and for the poor appetite. The crushed tubers are given as body refrigerant during summer seasons and good for treating diarrhoea.
4. Dioscorea oppositifolia
Botanical name: Dioscorea oppositifolia L., Sp. Pl.
Common name/ Local name: Chinese yam/ / Air potato/ Kavalakalasu
Family: Dioscoreaceae
Description: Dioscorea oppositifolia is a deciduous perennial creeping and climbing vine, the leaves are long-pointed with a heart-shaped base. Leaves can be alternate or opposite in arrangement on the stem. The margins, leaf-stalk and stems are purplish to red in color. The small yellowish-white flowers arise from the axils of the leaves. The flowers are bell-shaped and the male flowers are in bundles, spikes or panicles at the end of the branches. Flowers have a spicy fragrance similar to cinnamon. Flowering and fruiting have seen from August to October. Bulbils or small aerial tubers are produced in the axils of the leaves. The plant is distributed in Indo-Malaysian region and China
Significance: The tuber and bulbils are edible, although the bulbils are generally not collected and used as food. The edible tuber is used as a herbal tonic. It stimulates the stomach and spleen and has an effect on the lungs and kidneys. The tubers are medicinally used for chronic diarrhea, asthma, dry coughs, frequent or uncontrollable urination and diabetes. The flowers have cinnamon fragrance and the twining vine is attractive for arbors, trellises and porches.
5. Dioscorea bulbifera
Botanical name: Dioscorea bulbifera L., Sp. Pl.
Common name: Aerial Yam
Family: Dioscoreaceae
Description: Dioscorea bulbifera or Aerial yam is mostly seen in moist deciduous forests and also in plains. It is a perennial climbing plant with glabrous and non-spiny leaf and tuberous rootstock. The stems twine left-handed, scramble over the ground or twine into the surrounding vegetation and produce aerial axillary bulbils. The flowering and fruiting mainly occurs in September to October. The plant is often cultivated in tropical areas mainly for its roots and edible aerial bulbs. Distribution of plants is of Paleotropics.
Significance: Aerial tubers are boiled, baked or fried for consumption. It is with an agreeable taste. Edible species of Dioscorea have opposite leaves whilst poisonous species have alternate leaves. The aerial bulbs of this species contain toxic substances including the alkaloid dioscorine, this can be neutralized by thorough cooking. Both the tuber and the bulbil of wild races have medicinal uses. The root extract has been used to expel threadworm and the extract is dripped into wounds to expel worms and germs. The tuber has considered as diuretic and used as a remedy for diarrhoea and haemorrhoids.
6. Dioscorea tomentosa
Botanical name: Dioscorea tomentosa J. Koenig ex Spreng., Pl. Min. Cogn. Pug.
Local name: Noolamkizhangu
Family: Dioscoreaceae
Description: Dioscorea tomentosa mainly distributed in semi-evergreen, moist and dry deciduous forests and in India and Sri Lanka. The stem is twining to the left tomentose. Leaves are 3-foliolate with sub equal broadly ovate leaflets, oblique at base, abruptly acuminate distantly flowered fascicles at nodes on long peduncle. The flowering and fruiting mainly occurs in July to December.
Significance: it is used as a precursor for the synthesis of many steroidal drugs as corticosteroids, sex hormones and oral contraceptives. It has also been used in rheumatism.
7. Dioscorea belophylla
Botanical name: Dioscorea belophylla Voigt, Hort. Suburb. Calcutt.
Common name / Local name: Pear-Leaved Yam / Hekku
Family: Dioscoreaceae
Description: Dioscorea belophylla or Pear-leaved yam mostly seen in moist deciduous forests. It is a climber with small tubers. Stems are hairless, twining anti-clockwise. Leaves are usually opposite, simple, variable, ovate, heart-shaped or arrow shaped with round basal lobes or triangular, long-pointed, hairless and 9-nerved. Male flower is spikes, 1-2 together in the axils or sometimes forming leafless panicles. Female flower spikes are 5.5-12 cm long, solitary or 2 together, arising in leaf axils. Flowering is during July to October.
Significance: Pear-Leaved Yam has been used as a folk remedy to treat conjunctivitis, diarrhoea and dysentery. The saponin and alkaloid content are considered important. These toxic metabolites occur in varying concentrations in yam tubers. Yams have been well acknowledged by the herbalist community for generations claiming its efficiency in enhancing fertility in males. This may be due to the presence of steroidal sapogenins such as diosgenin which have been isolated from yams. Natural tendency to ward off microbes makes them good candidates for treating fungal and yeast infections. These compounds served as natural antibiotics, which help the body to fight infections and microbial invasion.
8. Dioscorea pubera
Botanical name: Dioscorea pubera Blume, Enum. Pl. Jav
Local name: Arikizhngu
Family: Dioscoreaceae
Description: Dioscorea pubera are mostly seen in semi-evergreen forests. The stem twining to the right and terete. Leaves are very rarely alternate, broadly elliptic, abruptly acuminate, coriaceous margins and glabrous. Male spikes 12 x 4 mm, solitary or 2-3 together, drooping; peduncle to 12 cm long, bracts lanceolate. Flowers closely packed with the flowering and fruiting occurs during February to March.
Significance: the species are known to be bitter in taste or unpalatable when taken raw. The rural and local people who use them as food supplements make them edible with different traditional practices. While investigating traditional food systems and palatability of D. pubera, the nutritive and antioxidant content not only enrich the diet of the local and rural people. It has ethnomedicinal importance . The tubers are used for birth control and for the treatment of skin infections. Tubers and vegetative parts of these species are used in multiple traditional medicinal formulations.
9. Dioscorea intermedia
Botanical name: Dioscorea intermedia Thw.,Enum. Pl. Zeyl.
Local name: Shoddikalasu
Family: Dioscoreaceae
Description: Dioscorea intermedia is an evergreen green forest plant with elliptic or oblanceolate leaf with cylindrical shaped tubers. October to January is the flowering and fruiting season. Its distribution ranges from Sri Lanka to Southern India in south Western Ghats and the distribution is rare.
Significance: the tuber and bulbils are edible, although the bulbils are generally not collected for food. It is used as a remedy for stomach ache and consumed for poor appetite.
10. Dioscorea kalkapershadii
Botanical name: Dioscorea kalkapershadii Prain&Burkill, J. Asiat. Soc. Bengal
Local name: Nara
Family: Dioscoreaceae
Description: Dioscorea kalkapershadii are mostly seen in ever green forests. It is climbers, stem slender, sparsely prickly, hirsute, length glabrescent. Leaves are alternate, compound, rarely a few of the uppermost leaves simple, rusty-hairy, rarely 3 near the tips, coarse, obovate or elliptic, acuminate, base acute, lateral asymmetric, smaller and wider in proportion. Spikes are long, rusty-tomentose, male flowers in 1-2-nate spikes on long racemes, fertile stamen with staminodes, ovary inferior and 3-celled with short styles. Capsules 3-winged and reflexed upwards and seeds winged at the base. The flowering season is from September to December. Its distribution is restricted and ranges from South Western Ghats.
Significance: The root and the bulb of the plant are used as a source of diosgenin, which is prepared as an extract. Dioscorea kalkapershadii is often promoted as a natural alterative for vaginal dryness in older women, menstrual cramps and weak bones. The application includes wild yam creams for the skin and to reduce menopausal symptoms such as hot flashes.
11. Dioscorea spicata
Botanical name: Dioscorea spicata Roth, Nov. Pl. Sp.
Local name: Kavalakizhzngu
Family: Dioscoreaceae
Description: Dioscorea spicata are mostly seen in Shola and semi-evergreen forests. It has elliptic lanceolate leaf and small cylindrical tuber, which is edible. Flowering and fruiting season is during September to December. The distribution of the taxon ranges from Sri Lanka to tropical rainforest to Southern India.
Significance: The tubers are used as a food source