Species
+

Cajanus cajan (L.) Huth

Ambatri, Cajan, Catjan, Catjan Pea

Climate known 65 photographs
Add one to my plants Sow seed

Every figure on this page is derived from public data by a stated rule and says its source; nothing here is written by a person or a model, except the Wikipedia passage, which is quoted and marked as such. How it is made.

Summary

The pigeon pea is a perennial legume from the family Fabaceae native to the Eastern Hemisphere. The pigeon pea is widely cultivated in tropical and semitropical regions around the world, being commonly consumed in the Indian Subcontinent, Southeast Asia, Africa, Latin America and the Caribbean.

Text from Wikipedia, “Pigeon pea”, CC BY-SA 4.0, quoted as written. Kept separate from everything derived here.

About the genus · Cajanus

The genus Cajanus is a member of the plant family Fabaceae. There are 37 species, mainly distributed across Africa, Asia and Australasia.

Text from Wikipedia, “Cajanus”, CC BY-SA 4.0, quoted as written.

Family
Fabaceae
Described by
(L.) Huth
Native to
Assam, India, West Himalaya
Wild records
380 in range· 371 open

At a glance

Warmest month
38°C
May, mean day; nights 26 °C (CHELSA)
Rain
1131mm/yr
6 wet months · peak Jul 321 mm (CHELSA)
Light
26–45DLI
mol/m²/day, winter to summer, open sky (CHELSA shortwave)
In short condensed by rule from the cultivation cards · not written by a person
Rain rule: a summer growing season, July to September in the northern hemisphere (July to September at the habitat, northern). Habitat rain 1131 mm a year, wettest July at 321 mm, driest December at 9 mm (habitat calendar, northern hemisphere). Open sky over the habitat: 26 to 45 mol/m²/day. Cold floor 7.5 °C (1st-percentile habitat night, NASA POWER).
Each sentence is one card's own one-line form, written by the same rule as the card (Its year, Rain, Light, Temperature); the note cannot say what a card does not. Months are given for the northern hemisphere (set your site in Settings to change this), and the habitat's own alongside. The cards · the figures.

Also known as Cajan cajan (L.) Huth; Cajan cajan (L.) Millsp.; Cajan indorum Medik.; Cajan inodorum Medik.; Cajanum thora Raf. and 28 more.

Cultivation

Its year Rain rule: a summer growing season, July to September in the northern hemisphere (July to September at the habitat, northern).

This species’ habitat figures, and what two fixed rules read from them.

The rain rule reads a summer growing season: 70% of the year's rain (815 mm of 1131 mm) falls in July to September, warmer than the year (wet-season mean 27.6 °C against a yearly mean of 25.8 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: January to March.

Read from the median year of CHELSA monthly rainfall and mean temperature across the envelope cells: 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 gives a season to reverse. A reading of the curves, not an observation of the plant.

Rain Habitat rain 1131 mm a year, wettest July at 321 mm, driest December at 9 mm (habitat calendar, northern hemisphere).

This species’ habitat figures, with their source.

1131 mm a year at the habitat, 815 mm of it July to September. Wettest month July at 321 mm, driest December at 9 mm. Across the envelope cells the year's total runs 739 mm to 1694 mm (10th to 90th percentile of each cell's own year) (median year across the envelope cells, CHELSA; habitat calendar, northern hemisphere).

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

Light Open sky over the habitat: 26 to 45 mol/m²/day.

This species’ habitat figures, with their source.

Open sky over the habitat: 26 to 45 mol/m²/day across the year (daily light integral, median year across the envelope cells, CHELSA; the lowest 10th-percentile month across the cells is 22, the highest 90th-percentile month 47).

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.

Warmth and air Cold floor 7.5 °C (1st-percentile habitat night, NASA POWER).

This species’ habitat figures, with their source.

Temperature

Coldest: the 1st-percentile night over 44 years at the typical cell is 7.5 °C, the absolute minimum 4.4 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 40.1 °C. Monthly means: coldest night 12.6 °C in January (across the envelope cells 8.6 °C to 17.7 °C), warmest day 38.2 °C in May (median year across the envelope cells, CHELSA). Cold floor: 7.5 °C, which is the 1st-percentile night over 44 years at the typical cell (NASA POWER).

NASA POWER daily minima and maxima 1981–2024 at the typical cell, lapse-corrected to its elevation; CHELSA monthly means, median year across the envelope cells, CHELSA. The cold floor is the figure named in its sentence. Not a measured survival limit for any plant in a pot.

Humidity

Relative humidity at the habitat: 43 to 66% across the year (monthly means, median year across the envelope cells, CHELSA). A figure about the air, saying nothing about how the plant takes water.

CHELSA relative humidity, median year across the envelope cells.

The figures the cards read from are in Climate below, and where they came from in Natural habitat.

Climate across the habitat

Habitat climate through the yearMean day from 25 °C in Jan to 38 °C in May; mean night from 13 °C in Jan to 27 °C in Jun. The cold quarter, Dec to Feb, is the three months around the coldest night. 1131 mm of rain a year, most in Jul. The bands show the 10th to 90th percentile across 353 habitat cells. Over 44 years at the typical cell the absolute minimum was 4.4 °C and the 99th-percentile day 40.1 °C; neither is dated to a month. Beneath: daily light integral and relative humidity through the year, each on its own scale.10°20°30°40°50°40.1° 99th-percentile day (undated)4.4° lowest night in 44 yrs (undated)°C · day and nightcold quarter0100200300400500mm rainDLI 26–45RH 43–66 %JanFebMarAprMayJunJulAugSepOctNovDec
day night rain 10th–90th percentile across 353 habitat cells cold quarter: the three months around the coldest night extremes over 44 years at the typical cell, marked at the edge: undated DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C25 / 21–2928 / 25–3233 / 30–3637 / 33–3938 / 33–4135 / 30–3831 / 27–3330 / 27–3231 / 28–3230 / 28–3228 / 26–3025 / 23–29
Night °C13 / 9–1815 / 11–2019 / 16–2323 / 21–2526 / 23–2827 / 22–2825 / 22–2724 / 21–2624 / 21–2520 / 19–2316 / 14–2013 / 10–18
Rain mm15 / 3–2415 / 2–2614 / 6–3514 / 3–6331 / 10–128147 / 65–253321 / 95–485288 / 121–434206 / 119–28558 / 29–18613 / 5–599 / 5–19
DLI30 / 27–3535 / 32–4041 / 39–4345 / 41–4744 / 40–4735 / 30–4026 / 24–3126 / 22–2929 / 27–3332 / 30–3430 / 28–3229 / 25–31
RH %54 / 49–5951 / 45–5646 / 41–5543 / 38–5848 / 40–6056 / 50–6665 / 60–6966 / 62–7064 / 59–6758 / 50–6353 / 48–6153 / 49–59

Each figure is the median across the 353 grid cells holding the 380 in-range records, with the 10th–90th percentile span across those cells after the slash where it differs. Extremes and elevation were read at the typical cell 1423:5254 (18.825, 82.725). Over 44 years there: absolute minimum 4.4 °C, 1st-percentile night 7.5 °C, 99th-percentile day 40.1 °C. Normals: CHELSA V2.1 1981–2010 climatology, 0.05° cells (each the mean of ~36 1 km pixels). Envelope: median and 10th–90th percentile of each month across the 353 distinct grid cells holding the 380 in-range records; extremes and elevation at the typical cell 1423:5254 (its coldest month's mean night nearest the median across cells); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell 19.00_82.500, lapse-corrected +198 m at 6.5 °C/km. Elevation: ETOPO 2022, 841 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 every in-range record's cell, not at the marker.
Openly licensed records inside the range, framed on where they fall.
NativeAssam, India, West Himalaya· introduced: Egypt, Cape Verde, Benin, Burkina, Gambia, The, Ghana, Guinea-Bissau, Guinea, Ivory Coast, Liberia, Mali, Nigeria, Niger, Senegal, Sierra Leone, Togo, Burundi, Central African Republic, Cameroon, Congo, Gabon, Gulf of Guinea Is., Rwanda, Zaïre, Chad, Djibouti, Eritrea, Ethiopia, Somalia, Sudan, Kenya, Tanzania, Uganda, Angola, Malawi, Mozambique, Zambia, Zimbabwe, Namibia, KwaZulu-Natal, Swaziland, Northern Provinces, Comoros, Mauritius, Madagascar, Réunion, Seychelles, Turkmenistan, Tadzhikistan, Uzbekistan, Transcaucasus, Afghanistan, Gulf States, Saudi Arabia, Yemen, China South-Central, Hainan, China Southeast, Taiwan, Bangladesh, East Himalaya, Laccadive Is., Nepal, Pakistan, Sri Lanka, Andaman Is., Cambodia, Laos, Myanmar, Nicobar Is., Thailand, Vietnam, Jawa, Lesser Sunda Is., Malaya, Philippines, Sulawesi, Sumatera, Bismarck Archipelago, New Guinea, New South Wales, Queensland, Nauru, New Caledonia, Vanuatu, Cook Is., Marquesas, Society Is., Caroline Is., Marianas, Hawaii, Florida, Maryland, Mexico Southwest, Honduras, Bahamas, Bermuda, Cayman Is., Cuba, Dominican Republic, Haiti, Jamaica, Leeward Is. AB Ant, Puerto Rico, Southwest Caribbean, Trinidad-Tobago, Windward Is., French Guiana, Guyana, Surinam, Venezuela, Bolivia, Colombia, Ecuador, Peru, Brazil Northeast, Brazil South, Paraguay
Kew's description“perennial or shrub” · “seasonally dry tropical”· quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Map marker27.57, 81.59 · in the densest population, 240 records (63% of those in range)
Evidence usedThe map marker and the climate envelope rest on all 380 georeferenced records inside the native range; the map shows only the 371 openly licensed ones, which alone would put the marker 15 km away. 963 records outside the range (gardens, roadsides, misidentifications) ignored.
The map markerthe map marker: the openly licensed record nearest the middle of the densest 1° population inside the densest 4° block of the 380 in-range records; it decides nothing.

Photographs

Cajanus cajanCajanus cajanCajanus cajanCajanus cajanCajanus cajanCajanus cajanCajanus cajanCajanus cajan

Photographs: (c) Josiah Londerée, some rights reserved (CC BY); (c) taniaat, some rights reserved (CC BY); (c) 胡正恆(Jackson Hu), some rights reserved (CC BY); (c) Malcolm Gould, some rights reserved (CC BY) (3); (c) Carlos Otávio Gussoni, some rights reserved (CC BY) (2).

Photographs: iNaturalist and Wikimedia Commons did not answer when this page was built; what is shown came from the sources that did.

Papers naming this species

Works whose title or abstract names Cajanus cajan, most cited first, from OpenAlex (CC0). A mention, not a cultivation source: nothing on this page is drawn from them.

Draft genome sequence of pigeonpea (Cajanus cajan), an orphan legume crop of resource-poor farmers
Rajeev K. Varshney, Wenbin Chen, Yupeng Li, Arvind K. Bharti (2011) · Nature Biotechnology
Influence of Soil Water Supply on the Plant Water Balance of Four Tropical Grain Legumes
TR Sinclair, MM Ludlow (1986) · Australian Journal of Plant Physiology
No‐tillage Effects on Soil Properties under Different Crops in Western Nigeria
Rattan Lal (1976) · Soil Science Society of America Journal
Will Elevated Carbon Dioxide Concentration Amplify the Benefits of Nitrogen Fixation in Legumes?
Alistair Rogers, Elizabeth A. Ainsworth, Andrew D. B. Leakey (2009) · PLANT PHYSIOLOGY
Development of genic-SSR markers by deep transcriptome sequencing in pigeonpea [Cajanus cajan (L.) Millspaugh]
Sutapa Dutta, Giriraj Kumawat, B. P. Singh, Deepak Gupta (2011) · BMC Plant Biology
Whole-genome resequencing of 292 pigeonpea accessions identifies genomic regions associated with domestication and agronomic traits
Rajeev K. Varshney, Rachit K. Saxena, Hari D. Upadhyaya, Aamir W. Khan (2017) · Nature Genetics

Similar habitat climate the 6 species whose habitat climate is nearest this one's: mean day and night, month by month, and rain on a log scale, in calendar order, so a habitat with the same seasons six months out is far, not near. Nothing else counts: not range, not family.

History & registers

Where this page came from built 2026-09-20 · dossier v2 · node
gbif.species answeredcarried from build of 2026-09-20 (offline re-derivation; the backbone was not asked)
gbif.synonyms answeredcarried from build of 2026-09-20 (offline re-derivation; the backbone was not asked)
gbif.vernacular answeredcarried from build of 2026-09-20 (offline re-derivation; the backbone was not asked)
wcvp.distribution answered
gbif.occurrences answeredGBIF occurrence download https://doi.org/10.15468/dl.3h4zam
climate answered
wikidata answeredcarried from build of 2026-09-20 (rederive); that build: carried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
wikipedia answeredcarried from build of 2026-09-20; this build: skipped
inat.taxon not askedcarried from build of 2026-09-20 (rederive)
inat.photos.wild answeredcarried from build of 2026-09-20; this build: skipped
inat.photos.cultivated nothing to reportcarried from build of 2026-09-20 (rederive); that build: carried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
commons not askedcarried from build of 2026-09-20 (rederive); that build: carried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
gbif.media answered
openalex answeredcarried from build of 2026-09-20; this build: skipped

Every upstream is recorded as having answered, reported nothing, or refused. Only “nothing to report” is ever shown as an absence. Records came from 131 datasets via GBIF.org; each carries its own licence.