Dioscorea nummularia var. belophylla Prain

Small climbers up to 5m. Tubers small, subfusiform. Trichomes absent. Stems twining to right, terete, shallowly longitudinal ridge, unarmed. Petioles 4–6.5 cm, slender. Leaves simple, opposite or sometimes alternate, dull green above, ovate to oblanceolate, 7.5–13 X 2–8 cm, base cordate or hastate with round basal lobes or deltoid, apex acuminate, margin entire, chartaceous, veins 9, main and first pair of veins reaching apex. Bulbils rare and narrow clavate. Male inflorescences simple, spicate, 1 or 2 per axil, 2.5–4 cm. Flowers green to brown, sessile; outer tepals ovate, inner tepals ovate to orbicular. Stamens 6, inserted on tepals base. Pistillode conical, tiny lobed. Female inflorescences simple, spicate, 1–3 per axil, 10–15 cm. Flowers sessile, outer and inner tepals oblong. Staminode absent. Ovary terete; styles short, free; stigma simple or bifid. Infructescences 5–8 cm including peduncles. Capsule obovate, 25–28 X 27–36 mm, base cuneate, apex retuse, deflexed. Seeds ovoid-round, wings broadly round.

Distribution: Nepal, W Himalaya, E Himalaya, Assam-Burma and S Asia.

Altitudinal range: 100–1600(–2700) m.

Ecology: Commonly found in the foothills.

Flowering: September–November. Fruiting: December–January.

Aletris alpestris var. occidentalis H.Hara

Helmia bulbifera (L) Kunth.; Polynome bulbifera (L) Salisb.

भ्याकुर Bhyakur, गिठ्ठा Gittha (Nepali).

Climbers to 25 m. Tubers globose to cylindric, solitary, shallowly buried. Trichomes absent. Stems twining to left, terete with deep longitudinal groove, unarmed. Petioles 5–15 cm, deep longitudinal channeled, lateral nodal flanges clasp stem. Leaves simple, alternate, bright to dark green and glaucous above, ovate to orbicular, 7–18 X 5–15 cm, base cordate with deep sinus, apex long acuminate, margin entire or undulate, thinly chartaceous, 5–9 veins, main and first pair of veins reaching apex. Bulbils abundant, globose to ovoid. Male inflorescences compound, spicate, 4–6 per axil, 8–30 cm. Flowers subsessile, pale green or red to brown, scented; outer tepals elliptic, inner tepals oblong. Stamens 6, inserted on tepal base. Pistillode conical, entire column. Female inflorescences simple spicate, 2–6 per axil, 5–25 cm. Flowers subsessile, light green; outer tepals and inner tepals oblong. Staminodes 6, inserted on tepal base. Ovary terete to elliptic; styles fused at base; stigma recurved. Infructescences 15–30 cm. Capsule pale green, oblong, 10–15 X 15–20 mm, base truncate to round, apex acute, reflexed. Seeds ovoid to ellipsoid, wings oblong.

Distribution: Nepal, W Himalaya, E Himalaya, Tibetan Plateau, Assam-Burma, S Asia, E Asia, SE Asia; Africa, Australasia.

Altitudinal range: 200–2600 m.

Ecology: Common twiner in old clearings and disturbed areas in seasonal forests, moist evergreen forests, hill evergreen forests and limestone vegetation.

Flowering: July–November. Fruiting: October–December.

This species is easily recognized by its large, broadly ovate to orbicular leaves and scented male flowers. Some population have smooth bulbils and tubers with white mucilage and are known locally as mitho githa (‘sweet yam’) while others with warty bulbils and tubers with reddish yellow mucilage are called tite githa (‘bitter yam’).

Tubers are boiled and eaten as a vegetable or pickled, and juice of the tubers is used as an anthelmintic (Manandhar, 2002).

Dioscorea nepalensis (Jacquem. ex. Prain & Burkill) Sweet ex Bernardi; Tamus nepalensis Jacquem. ex Prain & Burkill

कुकुर तरुल Kukur tarul, काँडे भ्याकुर Kande bhyakur (Nepali).

Climbers to at least 10 m. Tubers horizontal, ginger shaped, ligneous with finer roots. Trichomes absent. Stems twining to left, terete, unarmed. Petioles 2–7 cm, terete. Leaves simple, alternate, light green, ovate or subdeltoid, 5–13 X 3–11 cm, base cordate, apex acuminate, margin entire, subcoriaceous, hispid on vein beneath; upper surface glabrous, 5–7 veins, main and first pair of veins reaching apex. Bulbils absent. Male inflorescences simple, cymule of 2 flowers, 1–3 per axil, 10–20 cm. Flowers yellowish green, subsessile; outer and inner tepals equal, ovate. Stamens 6, inserted on torus margin, anthers didynamous. Pistillode with entire column. Female Inflorescences simple, spicate, solitary, flowers 6 or more, 5–20 cm. Flowers light green, subsessile; outer and inner tepals thick, ovate. Staminodes 6, inserted on torus margin. Ovary elliptic; styles free; stigma recurved. Infructescences 4–6 cm. Capsule red-straw with purple to brown spot, globose or obovoid, 15–25 X 20–30 mm, base round, apex emarginate, reflexed. Seeds ovate, wings round.

Distribution: Nepal, W Himalaya, E Himalaya, Tibetan Plateau, Assam-Burma, S Asia, E Asia and SE Asia.

Altitudinal range: 200–3900 m.

Ecology: Common climber in subtropical and temperate forests.

Flowering: June–August. Fruiting: August–September.

Juice of the tuber is used as an anthelmintic, and axillary bulbils are used for gastritis and dysentery (Manandhar, 2002).

Oncus esculentus Lour., Fl. Cochinch. 1:194 (1790).

सुथानी तरुल Suthani tarul, काँडे तरुल Kande tarul (Nepali).

Climbers to 10 m. Tubers cylindric to irregularly lobed in wild landraces. Trichomes T-shaped. Stems twining to left, terete, woody and densely spiny toward base, spines lax on upper stem. Petioles 6–14 cm, slender, lateral nodal flanges reduced to a pair of spines on either side of each node. Leaves simple, alternate, yellowish green to dark green above, pale below, broadly ovate to orbicular, 5–13 X 3–11 cm, base cordate, apex acuminate, margin entire, chartaceous; 7–9 veins with main vein, first and second vein pairs reaching apex. Bulbils absent. Male inflorescences simple, racemose, 1 or 2 per axil, 1.7–5 cm. Flowers solitary, pale green to yellow, sessile; outer tepals elliptic, inner tepals obovate. Stamens 6, inserted on tepals base. Pistillode with entire column with 3-longitudinal ridges. Female inflorescences simple, spicate, 1 or 2 per axil, 10–40 cm. Flowers pale yellow to green; outer tepals elliptic-ovate; inner tepals narrowly ovate-oblong. Staminodes 6, inserted on torus base. Ovary cylindric; styles with fused column; stigma recurved. Infructescences 10–40 cm. Capsule obovate-oblong, 10–15 X 15–20 mm, base truncate, apex with small sinus, reflexed. Seeds round, winged.

Distribution: Nepal, W Himalaya, E Himalaya, Assam-Burma, S Asia and SE Asia.

Altitudinal range: 2100–2600 m.

Ecology: In open areas human settlements or cultivated as a food crop.

Flowering: June–August. Fruiting: August–October.

Plants of the World (https://powo.science.kew.org/) recognized Dioscorea esculenta as a native species of Nepal.

Dioscorea glabra var. longifolia Prain & Burkill; Dioscorea oryzetorum var. latifolia Prain & Burkill

 पातली तरुल Patali tarul (Nepali).

Climbers to 25m. Tubers globose to clavate. Trichomes absent. Stems twining to right, terete, base woody and spiny. Petioles 2.5–6.5 cm, slender. Leaves simple, opposite, alternate to subopposite towards base, pale green to dark green and glaucous above; ovate, elliptic-oblong, 5–9 X 3–6 cm, base round or truncate to cordate; apex acute, margin entire, subcoriaceous; veins 5–7, main and first pair of veins reaching apex. Bulbils globose to ovoid. Male inflorescences simple or compound, spicate, 1 or 2 per axil 6–15(–30) cm. Flowers greenish brown, sessile; outer tepals ovate-oblong, inner tepals obovate. Stamens 6, inserted on torus. Pistillode conical, lobed. Female inflorescences simple, spicate; 1 or 2 per axil, 5.5–30 cm. Flowers pale green, subseesile; outer tepals ovate, inner tepals obovate. Staminodes 6, inserted on tepals base. Ovary ovate to elliptic; styles 3, free, falcate; stigma recurved. Infructescences 10–30 cm. Capsule yellowish green, ovate to obovate, 13–19 X 25–36 mm, base truncate to round, apex retuse, deflexed. Seeds ovoid to lenticular, wings circular.

Distribution: Nepal, W Himalaya, E Himalaya, Assam-Burma, S Asia, E Asia and SE Asia.

Altitudinal range: 100–900(–2400) m.

Flowering: July–November. Fruiting: October–February.

Ecology: Commonly found in open disturbed areas in mixed deciduous forest, hill evergreen forest, pine forest, rocky outcrop vegetation, beach forest.

This species is very variable in the size and shape of its leaves depending on the habitat it is found in, with larger leaves typical when growing in fertile soil. The lower surfaces of leaves and immature capsules have a whitish bloom of wax.

Dioscorea persimilis Prain & Burkill

वन तरुल Ban tarul (Nepali).

Climbers to at least 10 m. Tubers cylindric to clavate, descending vertically into substrate. Trichomes absent. Stems twining to right, terete with shallow longitudinal ridges, unarmed. Petioles 3.5–9.5 cm, terete. Leaves simple, opposite or subopposite toward base, yellowish green to dark green, narrow to broad ovate, 7–11 X 5–8 cm, base cordate, apex acuminate, margin entire, coriaceous, red purple pulvini at base; veins 5–7, with main, first and second vein pairs reaching apex. Bulbils globose to sub globose. Male inflorescences simple or compound, spicate, 2–4 per axil, 4.5–30 cm. Flowers green-yellow, sessile; outer tepals ovate, inner tepals obovate. Stamens 6, inserted on torus. Pistillode conical, lobed. Female inflorescences simple, spicate, 2–6 per axil, 5–20 cm, shallowly angled, weakly flexuous. Flowers light green, subsessile; outer tepals elliptic to ovate, inner tepals obovate. Staminodes 6, inserted on torus. Ovary elliptic to obovate; styles fused into a 3-lobed erect column; stigma oblong, recurved. Infructescences 6–20 cm. Capsule light green, obovate, 15–35 X 25–40 mm, base truncate, apex retuse, deflexed. Seeds ovoid lenticular, wings circular.

Distribution: Nepal, E Himalaya, Assam-Burma, S Asia, E Asia and SE Asia.

Altitudinal range: 300–1700 m.

Ecology: Chiefly found in open areas of mixed deciduous forests and limestone vegetation.

Flowering: July–November. Fruiting: November–March.

Tubers and bulbils are consumed as vegetables and as a staple food. Medicinally the crushed tubers are used as a cooling agent and for diarrhea. It is used as religious offering (Sharma & Bastakoti, 2009).

Dioscorea daemona Roxb.; Dioscorea hirsuta Blume; Dioscorea hispida var. daemona (Roxb.) Prain & Burkill

Robust climbers to 20 m. Tubers clavate to globose, often lobed, sparsely scattered with small roots. Trichomes dense on young shoots and inflorescences, simple. Stems twining to left, base woody and very prickly, mature stem glabrous. Petioles 6–20 cm, terete; petiolules 7–10 mm. Leaves palmately compound, 3-foliolates, alternate, yellowish green to dark green; terminal leaflet obovate, 10–22 X 6–12 cm, base cuneate, apex acuminate; lateral leaflet ovate, 8–15 X 6–9 cm, asymmetric, base obtuse, apex acute, chartaceous, veins 3, all reaching apex. Bulbils absent. Male inflorescences compound, spicate, 1–2(–3) per axil, 8–30 cm. Flowers dense, yellowish brown, sessile; outer and inner tepals ovate. Stamens 6, inserted on tepals base. Pistillode entire. Female inflorescences simple, raceme, 1(–2) per axil, 5–30 cm. Flowers light green, sessile; outer tepals obovate, inner tepals ovate-oblong. Staminodes 6, inserted on tepals base. Ovary cylindric to elliptic; styles free, recurved; stigma bifid. Infructescences 15–30 cm. Capsule glaucous green, oblong to obovate, 4–5.3 X 2–3.4 cm, base truncate, apex acute, reflexed. Seeds ovoid to lenticular, wings oblong to ovate.

Distribution: Nepal, W Himalaya, E Himalaya, Tibetan Plateau, Assam-Burma, S Asia, E Asia, SE Asia; and Australasia.

Altitudinal range: 200–1300 m.

Ecology: In open areas of mixed deciduous forest with well-drained soil.

Flowering: March–June. Fruiting: July–November.

The tubers are poisonous, but are consumed by Chepang people during severe food shortages after they have been chopped, soaked and boiled. Tubers are also used to treat skin disorders (Sharma & Bastakoti, 2009).

Dioscorea kamoonensis var. brevifolia Prain & Burkill; Dioscorea kamoonensis var. praecox Prain & Burkill; Dioscorea kamoonensis var. straminea Prain & Burkill

रानी भ्याकुर Rani bhyakur, त्यागुना Tyaguna (Nepali).

Slender climbers up to 3 m. Tubers ovoid to globose with fibrous roots. Trichomes present on all parts except inner whorl tepals, simple. Stems twining to left, terete, unarmed. Petioles 1.5–8 cm, slender; petiolules 5—10 mm. Leaves palmately compound, 3-or 5-foliolate, alternate, pale green to dark green above; terminal leaflet oblanceolate to obovate, 5–12 X 1.8–5 cm, base cuneate, apex acuminate; lateral leaflets elliptic to obovate, 4–8 X 1.5–3.5, base cuneate, apex acute, chartaceous; single main vein prominent below. Bulbils globose to ovoid. Male inflorescences simple or compound, racemose, 1–4 per axil, 2–8 cm. Flowers greenish yellow, sessile; outer tepals ovate, pubescent, inner tepals oblong, glabrous. Stamens 3, inserted on outer tepals base; staminodes 3. Pistillode entire. Female inflorescences simple, spicate, 2–5 per axil, 5–18 cm. Flowers light green, sessile; outer tepals ovate, pubescent, inner tepals obovate, glabrous. Staminodes 6, inserted on tepals base. Ovary ovoid, styles free, stigma recurved. Infructescences 8–15 cm. Capsules red to brown, oblong to elliptic, 15–25 X 10–15 mm, base truncate, apex retuse, reflexed. Seeds ovoid to lenticular with apical projection, wings oblong.

Distribution: Nepal, W Himalaya, E Himalaya, Tibetan Plateau, Assam-Burma, S Asia, E Asia, and SE Asia.

Altitudinal range: 100–1900(–3800) m.

Ecology: Common climber in open areas of hills and in evergreen and deciduous forests.

Flowering: August–October. Fruiting: October–December.

Dioscorea tenia R. Knuth

Climbers to 5 m. Tubers globose or ovoid with fibrous roots. Trichomes present on all parts except mature stem, simple. Stems twining to left, slender with shallow longitudinal ridge, unarmed. Petioles 2–3.5 cm, slender; petiolules 2–6 mm. Leaves palmately compound, 3- or 5-foliolate, alternate, pale to dark green; middle leaflet ovate to lanceolate, 4–7 X 2–3 cm, middle leaflet larger than lateral, puberulent along veins; first lateral leaflet 3.5–7 X 1–2.5 cm, secondary lateral leaflet 2–4 X 1–2 cm, base cuneate, apex acute to acuminate, margin entire or slightly undulate, chartaceous, single main vein prominent below. Bulbils abundant, spherical, black at maturity. Male inflorescences compound, racemose, 1–2 per axil, 4–15 cm. Flowers yellow to white, subsessile; outer tepals ovate to oblanceolate, inner tepals ovate. Stamens 3, inserted on tepals; staminodes 3, inserted in outer tepals. Pistillode entire. Female inflorescences simple, spicate, 1–3 per axil, 5–25 cm. Flowers pale green, sessile; outer tepals oblong, inner tepals ovate. Staminodes 6, inserted on tepals base. Ovary T–shaped, styles 3, free, fused at base; stigma lobed. Infructescences 5–25 cm. Capsule oblong, 15 X 10 mm, base and apex round, reflexed. Seeds oblong, wings wide oblong.

Distribution: Nepal, W Himalaya, E Himalaya, Tibetan Plateau, Assam-Burma, S Asia and E Asia.

Altitudinal range: 1100–2100 m.

Ecology: Open shrubby deciduous forests, moist hill areas and forest margins.

Flowering: August–October. Fruiting: October–December.

Dioscorea pentaphylla var. communis Prain & Burkill; Dioscorea pentaphylla var. palmata Burkill; Dioscorea triphylla L.

मिठे तरुल Mithe tarul, जगल्टेभ्याकुर Jagalte bhyakur, रानी भ्याकुर Rani bhyakur (Nepali).

Climbers to 20 m. Tubers cylindric to clavate. Trichomes present except male tepals and inner whorl of tepals of female flowers, simple. Stems twining to left, terete, base woody and densely prickly, usually glaucous, mature stem glabrous. Petioles 6–20 cm, slender, sometimes spiny; petiolules 7–10 mm. Leaves palmately compound, 3- or 5-foliolates, alternate, yellowish green to dark green above, obovate to oblanceolate, terminal leaf 5–14 X 4–6 cm; first lateral leaflet 8–11 X 3–5 cm, secondary lateral leaflets 6–9 X 2–4 cm, base cuneate, apex acuminate, margin entire, chartaceous, main vein prominent below. Bulbils globose to ovoid. Male inflorescences compound, spicate, 1 or 2 per axil, 5–30 cm, strong fragrant. Flowers yellowish green, subsessile; outer and inner tepals ovate-oblong. Stamens 3, inserted on torus rim; staminodes 3. Pistillode ovoid, entire. Female inforescences simple, spicate, 1–3 per axil, 3.7–25 cm. Flowers yellowish green, sessile; outer tepals ovate, inner tepals oblong. Staminodes 6, inserted on torus rim. Ovary ovoid, erect; styles free, stigma recurved. Infructescences 15–45 cm. Capsule light green, oblong to elliptic, 11–21 X 8.5–12.5 mm, base truncate, apex retuse, reflexed. Seeds lenticular to ovoid, wings oblong.

Distribution: Nepal, W Himalaya, E Himalaya, Tibetan Plateau, Assam-Burma, S Asia, E Asia, SE Asia; Australasia.

Altitudinal range: 100–2700 m.

Ecology: Common climber in open areas of disturbed mixed deciduous forests and hill evergreen forests and in cultivated land.

Flowering: August–December. Fruiting: November–January.

Tubers are boiled, peeled, and prepared as a vegetable and in curries and pickles. Juice extracted from the plant is applied to boils (Manandhar, 2002).

Dioscorea clarkei Prain & Burkill; Dioscorea sikkimensis Prain & Burkill

कुकुर तरुल Kukur tarul, भ्याकुर Bhyakur (Nepali).

Climbers to 5 m. Tubers ginger shaped, horizontally spreading, much branched. Trichomes absent. Stems twining to left, terete with shallowly longitudinal ridges, unarmed. Petioles 3–6.5 cm, slender. Leaves simple, alternate, yellowish green to dark green, ovate, 2–10 X 1.6–8 cm, base cordate, apex acuminate, margin entire, subcoriaceous; veins 5–7, main and first pair reaching apex. Bulbils occasionally present, globose to clavate. Male inflorescences simple, 3–6 per axil, spicate with cymule of 2 or 3 flowers, 3.5–9.5 cm. Flowers white to yellow, sessile; outer and inner tepals elliptic-oblong. Stamens 6, inserted on torus; anthers broadly ovate to oblong. Pistillode entire. Female inflorescences spicate, simple, 1 or 2 per axil, 1.7–11 cm. Flowers pale green, sessile; outer and inner tepals elliptic to oblong. Staminodes 6, inserted on torus rim; Ovary elliptic, styles free, stigma recurved. Infructescences 7.5–11 cm. Capsule yellowish green, ovate or obovate, 12–22 X 16–21 mm, base truncate, apex retuse, reflexed. Seeds lenticular or ovoid, wings semi-circular to round.

Distribution: Nepal, E Himalaya, Assam-Burma and SE Asia.

Altitudinal range: 100–1100 m.

Ecology: Generally, in open areas of limestone vegetation.

Flowering: June–September. Fruiting: September–December.

This species closely resembles with D. deltoidea morphologically, but the latter has dark green leaves. Male inflorescences are spicate with sessile cymose clusters of 3 flowers in each node.

Dioscorea anguina Roxb.

पङ्लाङ्ग तरुल Panglang tarul (Nepali).

Climbers to 5 m. Tubers narrowly cylindrical with few rootlets. Trichomes simple. Stems twining to right, cylindrical with shallow smooth longitudinal ridges, unarmed. Petioles 5.5–10 cm, slender. Leaves simple, opposite, yellowish green to dark green, ovate, 8–16.5 X 5.2–8 cm, base shallow cordate to round, cuspidate to short caudate, apex acuminate, margin entire, subcoriaceous, persistently pubescent; prominent hairs present on vein in lower surface, veins 5–7, main vein, first and second vein pairs reaching apex. Bulbils occasional, globose to ovoid. Male inflorescences simple or compound, spicate, 4-6 per axils, 10–30 cm. Flowers brown, sessile; outer tepals ovate, pubescent, inner tepals ovate, glabrous. Stamens 6, erect, inserted on torus rim. Pistillode conical, lobed. Female inflorescences simple or compound, spicate, 2–4 per axils, spikes bearing distant flowers. Flowers light green, sessile; outer and inner tepals ovate. Staminodes 6, inserted on torus. Ovary densely pubescent, styles stout, stigma divergent. Infructescences 8–20 cm. Capsule greenish yellow, reniform orbicular, 2.1- 3.5 X 1–1.5 cm, base shallowly truncate, apex retuse. Seeds ovoid to ellipsoid, surrounded by circular wing.

Distribution: Nepal, E Himalaya, Assam-Burma, S Asia and SE Asia.

Altitudinal range: 100–1000 m.

Ecology: Mostly in open areas of tropical forest and dry places.

Flowering: September–December. Fruiting: November–January.

The inner tepals of male flowers are chartaceous, glabrous, and longer, narrow than those of female flowers.