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Dioscorea esculenta; photograph (c) 胡正恆(Jackson Hu), some rights reserved (CC BY) CC BY(c) 胡正恆(Jackson Hu), some rights reserved (CC BY) · observed growing wild · 2023-01-14

Dioscorea esculenta (Lour.) Burkill

Lesser yam; Asiatic yam; Chinese yam

Dioscoreaceae · Assam, Bangladesh +17 · listed by its genus as a bulb, tuber or caudex

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Dioscorea esculenta, photograph (c) 胡正恆(Jackson Hu), some rights reserved (CC BY)Dioscorea esculenta, photograph (c) 胡正恆(Jackson Hu), some rights reserved (CC BY)Dioscorea esculenta, photograph Amer Amer Lazim, CC BY-SA, via GBIFDioscorea esculenta, photograph Kouakou Jérôme Yao, CC BY-SA, via GBIFDioscorea esculenta, photograph H. Zell, CC BY-SA 3.0, via Wikimedia CommonsDioscorea esculenta, photograph H. Zell, CC BY-SA 3.0, via Wikimedia Commons 12 photographs ›
Habitat figures
Cold floor (1 night in 100)
20.5°C
Record low 17.7 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
28°C
Jan, Feb, Mar, Apr, May, Jun, Sep, Oct, Nov and Dec at the habitat CHELSA
Rain a year (median across the range)
1,785mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
29–35DLI
Lowest to highest month (DLI) CHELSA
The year in the habitat's months, not shifted
  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec
Rain spread: 70% of the median year's rain takes 8 months, so no short rainy season. rain rule, CHELSA
Not shifted: the shift rule does not apply to this habitat. The chart is in the habitat's months.

Summary

Dioscorea esculenta is a species of flowering plant in the family Dioscoreaceae. It is sometimes referred to by the common name lesser yam, and is native to Island Southeast Asia and introduced to Near Oceania and East Africa by early Austronesian voyagers. This yam is grown for its edible tubers, though it has smaller tubers than the more widely-cultivated Dioscorea alata and is usually spiny.

Quoted from Wikipedia, "Dioscorea esculenta", CC BY-SA 4.0.

About the genus · Dioscorea

Dioscorea is a genus of over 600 species of flowering plants in the family Dioscoreaceae, native throughout the tropical and warm temperate regions of the world. The vast majority of the species are tropical, with only a few species extending into temperate climates. It was named by the monk Charles Plumier after the ancient Greek physician and botanist Dioscorides.

Quoted from Wikipedia, "Dioscorea", CC BY-SA 4.0.

Cultivation

Grouped as a bulb, tuber or caudex, listed under the genus Dioscorea in the archetype table, and Kew describes it as “climbing tuberous geophyte”.

Seasons

The rain rule reads no short rainy season: 70% of the median year's rain (1,358 mm of 1,849 mm) takes 8 months, December to May and August to September. Mean temperature moves 2.0 °C between the warmest and coldest month. Months are the habitat's, southern hemisphere. The temperature curve moves under 4 °C between the warmest and coldest month, where the shift rule does not apply, so they are not shifted for a collection elsewhere.

Rain

1,849 mm in the median year at the habitat, 1,358 mm of it December to May and August to September. Wettest month March at 203 mm, driest month November at 108 mm. Across the grid cells of the range the year's total runs 1,450 mm to 3,178 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,785 mm, is the year's rain at the top of the page; the 1,849 mm here is the median year's, the twelve monthly medians added, which the rain rule reads. Habitat calendar, southern hemisphere; median year across the grid cells of the range, CHELSA.

Light

Open sky over the habitat: 29 to 35 mol/m²/day across the year (daily light integral, median year across the grid cells of the range, CHELSA; the lowest 10th-percentile month across the cells is 24, the highest 90th-percentile month 43).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 20.5 °C, the absolute minimum 17.7 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 36.9 °C. Monthly means: the coldest month's mean nightly low 22.0 °C in January (across the grid cells of the range 13.1 °C to 26.1 °C), the warmest month's mean daily high 28.3 °C in March and May (median year across the grid cells of the range, CHELSA). Cold floor: 20.5 °C, which is the 1st-percentile night over 44 years at a typical spot in the range (NASA POWER).

Humidity

Relative humidity at the habitat: 65 to 66% across the year (monthly means, median year across the grid cells of the range, CHELSA). A figure about the air, saying nothing about how the plant takes water.

How this section is made

Each card states this species' habitat figures with their sources, and what two fixed rules read from them; nothing here says what the plant does, wants or tolerates. The rules · the terms.

Seasons. Read from the median year of CHELSA monthly rainfall and mean temperature across the grid cells of the range: the rain rule takes the smallest set of months carrying 70% of the rain and calls it winter when its mean is more than half a degree below the year's, summer when more than that above, and neither in between; the temperature rule, used only under 120 mm, names the cooler six months when they are at least a degree cooler than the other six. Months are shifted for the other hemisphere only where the temperature curve moves 4 °C or more and the habitat lies 10° or more from the equator. A reading of the curves, not an observation of the plant.

Rain. CHELSA monthly precipitation, median year across the grid cells of the range. The rain that falls where the species is recorded; nothing about how the plant takes water.

Light. CHELSA shortwave radiation at each envelope cell, a daily-mean flux taken to a daily total and converted at 2.07 mol of PAR per MJ. The sky over the habitat, measured; what reaches a plant under a rock, a shrub or a shade cloth is not.

Temperature. NASA POWER daily minima and maxima over 44 years at a typical spot in the range, lapse-corrected -123 m to its elevation; CHELSA monthly means, median year across the grid cells of the range. The cold floor is the 1st-percentile night named in its sentence. Not a measured survival limit for any plant in a pot.

Humidity. CHELSA relative humidity, median year across the grid cells of the range.

Group. Listed under the genus Dioscorea in the archetype table, and Kew describes it as “climbing tuberous geophyte”. A group is taken only where Kew's description of the species agrees with the table's listing. The table gives no figure and no prose; the cold floor is the habitat's alone.

Climate across the habitat

Habitat months, southern hemisphere

Habitat climate of Dioscorea esculenta through the yearWarmest months January, February, March, April, May, June, September, October, November and December, mean daily high 28 °C; coldest month January, mean nightly low 22.0 °C; 1,849 mm of rain in the median year (the twelve monthly medians added). Medians across the range, from CHELSA; the extremes at the edge from NASA POWER. Habitat months, southern hemisphere.5°10°15°20°25°30°35°40°36.9° 99th-percentile day, NASA POWER17.7° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0100200300400500mm rainDLI 29–35RH 65–66%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 16 habitat cells, CHELSA cold quarter: the three months around the coldest month's mean nightly low extremes over 44 years at a typical spot in the range, from NASA POWER, marked at the edge, in no month DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C28 / 20–3028 / 20–3128 / 20–3328 / 20–3428 / 19–3228 / 18–3127 / 18–3127 / 18–3128 / 20–3028 / 21–3028 / 21–3028 / 20–29
Night °C22 / 13–2622 / 14–2624 / 13–2624 / 13–2625 / 13–2625 / 12–2524 / 11–2524 / 11–2523 / 11–2523 / 12–2523 / 13–2623 / 13–26
Rain mm192 / 7–386196 / 20–416203 / 48–420143 / 62–289157 / 98–213127 / 57–310128 / 34–322130 / 20–368171 / 19–297128 / 28–292108 / 22–258166 / 4–438
DLI32 / 26–3735 / 27–3634 / 27–3933 / 27–4132 / 27–3829 / 25–3630 / 26–3533 / 27–3634 / 29–3932 / 30–4331 / 27–4330 / 24–39
RH %65 / 54–7165 / 54–7265 / 54–7165 / 57–7065 / 62–6965 / 64–7065 / 63–7066 / 63–6965 / 63–6865 / 61–6965 / 57–7066 / 54–70

Records on both sides of the equator: the 5 cells at least 10° south of it have seasons six months apart and are left out, not combined into a year no place has. These figures are across the 16 cells that remain: the 5 at least 10° north and the 11 within 10° of the equator, which stay in either way.

How this section is made
Each figure is the median across the 16 grid cells on land that hold in-range records (18 records in those cells; 3 more cells hold records but no land by the elevation layer, so those records sit at sea and the cells are left out), with the 10th–90th percentile span across those cells after the slash where it differs. A dash is a month one or more of those cells has no figure for in the grid (a variable CHELSA does not carry there), so no median is taken rather than one over fewer cells. Extremes and elevation were read at a typical spot in the range, cell 1679:5639 (6.025, 101.975). Over 44 years there: absolute minimum 17.7 °C, 1st-percentile night 20.5 °C, 99th-percentile day 36.9 °C. Normals: CHELSA V2.1 1981–2010 climatology, 0.05° cells (each the mean of ~36 1 km pixels). Across the range: median and 10th–90th percentile of each month across the 16 distinct grid cells holding 18 of the 30 in-range records (3 further cells with records at sea, by the elevation layer, left out) on the northern side of the equator (5 cells poleward of 10° north, 5 poleward of 10° south: the two sides' seasons are not combined, and cells within 10° of the equator stay in); extremes and elevation at the typical cell 1679:5639 (its coldest month's mean nightly low nearest the median across cells); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell 6.00_101.875, lapse-corrected -123 m at 6.5 °C/km. Elevation: ETOPO 2022, 12 m (cell mean).

Natural habitat

Native range as published by WCVP; the marker is where the records are densest and decides nothing: the climate was read across the cells of the in-range records placed well enough to read one, not at the marker.
Openly licensed records inside the range, framed on where they fall.
NativeAssam, Bangladesh, East Himalaya, Nepal, West Himalaya, Cambodia, Myanmar, Thailand, Vietnam, Borneo, Jawa, Lesser Sunda Is., Malaya, Maluku, Philippines, Sulawesi, Sumatera, Bismarck Archipelago, New Guinea · introduced: Burkina, Ivory Coast, Madagascar, Seychelles, China South-Central, Hainan, China Southeast, Nansei-shoto, Taiwan, India, Maldives, Andaman Is., Nicobar Is., Fiji, Niue, Samoa, Tonga, Wallis-Futuna Is., Cook Is., Pitcairn Is., Society Is., Tuamotu, Caroline Is., Marianas, Mexico Central, Cuba, Leeward Is. AB Ant, Puerto Rico, Trinidad-Tobago, Windward Is. · regions are the level-3 units of the World Geographical Scheme for Recording Plant Distributions, as Kew's World Checklist records ranges, some under historical names such as Yugoslavia or Czechoslovakia (how).
Map marker-10.533, 142.217 · in the densest population, 23 records (24% of those in range)
Kew's description“climbing tuberous geophyte” · “seasonally dry tropical” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 96 georeferenced records inside the native range; the climate across the range on the 18 of them in the land cells it reads, of 30 placed to within 10 km; the map shows only the 89 openly licensed ones, which alone would put the marker in the same place. 131 records outside the WCVP native range not used. 66 in-range records are placed to worse than 10 km, or with no stated accuracy (admitted only as a person's observation to three decimals), and stay on the map but off the climate.
How this section is made
The map marker: the openly licensed record nearest the middle of the densest 1° population of the 96 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Dioscorea esculenta, photograph 1did not loadDioscorea esculenta, photograph 2did not loadDioscorea esculenta, photograph 3did not loadDioscorea esculenta, photograph 4did not loadDioscorea esculenta, photograph 5did not loadDioscorea esculenta, photograph 6did not load

Photographs: (c) 胡正恆(Jackson Hu), some rights reserved (CC BY) (2); Amer Amer Lazim, CC BY-SA, via GBIF; Kouakou Jérôme Yao, CC BY-SA, via GBIF; H. Zell, CC BY-SA 3.0, via Wikimedia Commons (2).

Similar habitat climate The 6 nearest by mean daily high, mean nightly low and rain, month by month. How.

Eucalyptus deglupta Eucalyptus deglupta Indonesian gum Photo: CC BY, Marilyne Busque-DuboisDerris elliptica Derris elliptica Oiltree Photo: CC BY, pbsgPentaspadon motleyi Pentaspadon motleyi Pelong Photo: CC BY, fmunozNepenthes neoguineensis Nepenthes neoguineensis Nepenthaceae Photo: CC BY, Alfindra PrimaldhiClaoxylon indicum Claoxylon indicum Laping Budak Photo: CC BY, Donald DavesneFicus brusii Ficus brusii Moraceae Photo: CC BY, Cheongweei Gan

Other Dioscorea 31 in the reference

Dioscorea alata Dioscorea alata Water yam Photo: CC BY, chiuluanDioscorea balcanica Dioscorea balcanica Balkan Yam Photo: CC BY-SA, Kurt Stüber Dioscorea basiclavicaulis Dioscoreaceae Dioscorea bemandry Dioscorea bemandry Dioscoreaceae Photo: CC0, author not statedDioscorea bulbifera Dioscorea bulbifera Air potato Photo: CC0, author not statedDioscorea caucasica Dioscorea caucasica Dioscoreaceae Photo: CC BY, Yurii BasovDioscorea cayenensis Dioscorea cayenensis Yellow Guinea yam Photo: CC0, TomwsulcerDioscorea cirrhosa Dioscorea cirrhosa Shoulang Yam Photo: CC BY, Francisca WuDioscorea collettii Dioscorea collettii Dioscoreaceae Photo: CC BY, 謝麗霦Dioscorea communis Dioscorea communis Black bryony Photo: CC BY, Sabarni SarkerDioscorea deltoidea Dioscorea deltoidea Elephant's Foot Photo: CC BY, Ramnarayan KDioscorea dodecaneura Dioscorea dodecaneura Ornamental yam Photo: CC BY, Paulo Mascaretti all 32 ›

Names & registers

Also known as Dioscorea aculeata; Dioscorea aculeata var. spinosa; Dioscorea esculenta subsp. fasciculata; Dioscorea esculenta subsp. tiliifolia; Dioscorea esculenta var. esculenta and 15 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Dioscoreaceae
Described by
(Lour.) Burkill
Native to
Assam, Bangladesh, East Himalaya +16
Wild records
96 in range · 89 open

Every figure here is derived from public data by a stated rule and names its source; nothing about this species is written for its page by a person or by AI, apart from the marked, credited quotations. How →

Where this page came from built 2026-10-22
GBIF species record gbif.species answeredasked 2026-10-22
GBIF synonyms gbif.synonyms answeredasked 2026-10-22
GBIF common names gbif.vernacular answeredasked 2026-10-22names fetched 2026-10-22
WCVP native range wcvp.distribution answeredas of 2026-06-04
GBIF occurrence records gbif.occurrences answeredas of 2026-10-21GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21; 4 records within 1 km of a botanic garden, herbarium or zoo left out (3 at a botanic garden or arboretum, 1 at a herbarium; Wikidata's list)
Habitat climate climate answeredasked 2026-10-22
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell 6.00_101.875, lapse-corrected -123 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22IPNI and POWO linked by Kew's number for Dioscorea esculenta (Lour.) Burkill (the item's: IPNI 30332005-2, POWO 317946-1)
Wikipedia wikipedia answeredasked 2026-10-22
iNaturalist photographs, wild inat.photos.wild answeredasked 2026-10-22from iNaturalist's open data of 2026-09-27: research-grade observations with an open-licence photograph, the 24 whose photographs iNaturalist received last (the open data holds no votes); filled 2026-10-22
iNaturalist photographs, cultivated inat.photos.cultivated not asked
GBIF media gbif.media answeredasked 2026-10-22
Wikimedia Commons commons answeredasked 2026-10-22
OpenAlex papers openalex not askednot yet asked for this reference; a later fill takes the papers from OpenAlex's snapshot

Every source is recorded as having answered, reported nothing, refused, failed, not been asked, or answered twice where one answer is taken (“not taken: two items answered”), and, for a source asked when this page was built, when: the figures are as the source held them that day; a source read from a file (Kew's World Checklist, a GBIF download) says "as of" the file's day instead; a row carried from an earlier build of the page names that build instead. Only “nothing to report” is ever shown as an absence. Records came from 42 datasets via GBIF.org; each carries its own licence.

Cultifolio

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