Species
+

Thunbergia alata Bojer ex Sims

Black Eyed Susan, Black eyed Susan vine, Black-eyed Susan, Black-eyed Susan clock vine, Bright eyes, Winged clockvine, Black-eyed Susan, Black-eyed Susan vine

Climate known 61 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

Thunbergia alata, commonly called black-eyed Susan vine, is a herbaceous perennial climbing plant species in the family Acanthaceae. It is native to Eastern Africa, and has been naturalized in other parts of the world.

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

About the genus · Thunbergia

Thunbergia is a genus of flowering plants in the family Acanthaceae. It includes 150 species native to tropical and subtropical regions of sub-Saharan Africa, Madagascar, southern Asia, New Guinea, and Australia. Thunbergia species are vigorous annual or perennial vines and shrubs growing to 2–8 m tall. More on Wikipedia ›

The opening of Wikipedia, “Thunbergia”, CC BY-SA 4.0, quoted as written.

Family
Acanthaceae
Described by
Bojer ex Sims
Native to
Ghana, Guinea, Ivory Coast +26
Wild records
209 in range· 81 open

At a glance

Warmest month
26°C
Feb, mean day; nights 17 °C (CHELSA)
Rain
1084mm/yr
12 wet months · peak Apr 147 mm (CHELSA)
Light
28–37DLI
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, October to April at the habitat (not shifted). Habitat rain 1084 mm a year, wettest April at 147 mm, driest June at 27 mm (habitat calendar, southern hemisphere). Open sky over the habitat: 28 to 37 mol/m²/day. Cold floor 9.0 °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 Endomelas alata (Bojer ex Sims) Raf.; Thunbergia alata Bojer; Thunbergia alata var. alba Paxton; Thunbergia alata var. albiflora Hook.; Thunbergia alata var. minor S.Moore and 20 more.

Cultivation

Its year Rain rule: a summer growing season, October to April at the habitat (not shifted).

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 (850 mm of 1084 mm) falls in October to April, warmer than the year (wet-season mean 20.5 °C against a yearly mean of 19.4 °C). Months are the habitat's, southern hemisphere, within 10° of the equator; with no thermal season there there is no season to reverse, so they are not shifted for a collection elsewhere.

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 1084 mm a year, wettest April at 147 mm, driest June at 27 mm (habitat calendar, southern hemisphere).

This species’ habitat figures, with their source.

1084 mm a year at the habitat, 850 mm of it October to April. Wettest month April at 147 mm, driest June at 27 mm. Across the envelope cells the year's total runs 798 mm to 1864 mm (10th to 90th percentile of each cell's own year) (median year across the envelope cells, CHELSA; habitat calendar, southern 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: 28 to 37 mol/m²/day.

This species’ habitat figures, with their source.

Open sky over the habitat: 28 to 37 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 20, the highest 90th-percentile month 43).

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 9.0 °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 9.0 °C, the absolute minimum 5.1 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 29.1 °C. Monthly means: coldest night 11.9 °C in July (across the envelope cells 6.5 °C to 18.5 °C), warmest day 26.1 °C in February (median year across the envelope cells, CHELSA). Cold floor: 9.0 °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: 58 to 64% 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 21 °C in Jul to 26 °C in Feb; mean night from 12 °C in Jul to 17 °C in Feb. The cold quarter, Jun to Aug, is the three months around the coldest night. 1084 mm of rain a year, most in Apr. The bands show the 10th to 90th percentile across 159 habitat cells. Over 44 years at the typical cell the absolute minimum was 5.1 °C and the 99th-percentile day 29.1 °C; neither is dated to a month. Beneath: daily light integral and relative humidity through the year, each on its own scale.10°15°20°25°30°35°29.1° 99th-percentile day (undated)5.1° lowest night in 44 yrs (undated)°C · day and nightcold quarter050100150200250300mm rainDLI 28–37RH 58–64 %JanFebMarAprMayJunJulAugSepOctNovDec
day night rain 10th–90th percentile across 159 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 / 22–3026 / 23–3126 / 23–3024 / 21–2823 / 19–2822 / 18–2721 / 17–2622 / 19–2724 / 20–2724 / 21–2824 / 22–2825 / 22–29
Night °C16 / 12–2217 / 12–2216 / 13–2216 / 12–2114 / 10–2013 / 7–1912 / 7–1913 / 8–1914 / 9–1915 / 11–2015 / 12–2116 / 12–21
Rain mm124 / 35–278111 / 40–246122 / 88–224147 / 48–27091 / 17–21227 / 8–13029 / 3–13934 / 6–15153 / 13–16596 / 38–214124 / 87–182126 / 65–237
DLI37 / 33–4137 / 34–4335 / 31–4132 / 27–3630 / 23–3528 / 20–3428 / 21–3431 / 25–3636 / 29–4137 / 31–4236 / 31–4237 / 32–40
RH %63 / 56–6862 / 55–6763 / 56–6864 / 59–7062 / 56–7059 / 53–6758 / 50–6759 / 51–6660 / 50–6561 / 52–6663 / 56–6763 / 58–68

Each figure is the median across the 159 grid cells holding the 207 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 1972:4312 (-8.625, 35.625). Over 44 years there: absolute minimum 5.1 °C, 1st-percentile night 9.0 °C, 99th-percentile day 29.1 °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 159 distinct grid cells holding the 207 in-range records; extremes and elevation at the typical cell 1972:4312 (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 -8.50_35.625, lapse-corrected -263 m at 6.5 °C/km. Elevation: ETOPO 2022, 1260 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.
NativeGhana, Guinea, Ivory Coast, Liberia, Nigeria, Sierra Leone, Burundi, Central African Republic, Cameroon, Congo, Rwanda, Zaïre, Djibouti, Eritrea, Ethiopia, Somalia, Sudan, Kenya, Tanzania, Uganda, Malawi, Mozambique, Zambia, Zimbabwe, Botswana, KwaZulu-Natal, Swaziland, Northern Provinces, Madagascar· introduced: Comoros, Mauritius, Réunion, Seychelles, China South-Central, China Southeast, Ogasawara-shoto, Taiwan, Assam, Bangladesh, East Himalaya, India, Nepal, Sri Lanka, Myanmar, Vietnam, Jawa, Lesser Sunda Is., Malaya, Fiji, New Caledonia, Samoa, Vanuatu, Society Is., Marianas, Hawaii, Texas, Alabama, Florida, Mexico Central, Mexico Northeast, Mexico Southwest, Mexico Southeast, Belize, Costa Rica, El Salvador, Guatemala, Honduras, Bahamas, Cuba, Dominican Republic, Haiti, Jamaica, Leeward Is. AB Ant, Puerto Rico, Trinidad-Tobago, Windward Is., Guyana, Surinam, Venezuela, Bolivia, Colombia, Ecuador, Peru, Brazil West-Central, Brazil Northeast, Brazil Southeast, Brazil North, Brazil South, Argentina Northeast, Argentina Northwest, Paraguay
Kew's description“climbing shrub” · “seasonally dry tropical”· quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Map marker-1.255, 36.755 · in the densest population, 97 records (46% of those in range)
Evidence usedThe map marker and the climate envelope rest on all 209 georeferenced records inside the native range; the map shows only the 81 openly licensed ones, which alone would put the marker 732 km away. 1599 records outside the range (gardens, roadsides, misidentifications) ignored. 2 in-range records are placed to worse than 10 km and stay on the map but off the climate.
The map markerthe map marker: the openly licensed record nearest the middle of the densest 1° population inside the densest 4° block of the 209 in-range records; it decides nothing.

Photographs

Thunbergia alataThunbergia alataThunbergia alataThunbergia alataThunbergia alataThunbergia alataThunbergia alataThunbergia alata

Photographs: (c) Viktor, some rights reserved (CC BY); (c) ldgc, some rights reserved (CC BY-SA) (2); (c) 呂一起(Lyu yi-chi), some rights reserved (CC BY) (5).

Photographs: iNaturalist 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 Thunbergia alata, most cited first, from OpenAlex (CC0). A mention, not a cultivation source: nothing on this page is drawn from them.

delta 6 Hexadecenoic acid is synthesized by the activity of a soluble delta 6 palmitoyl-acyl carrier protein desaturase in Thunbergia alata endosperm.
Edgar B. Cahoon, A. M. Cranmer, John Shanklin, John B. Ohlrogge (1994) · Journal of Biological Chemistry
Isoforms of acyl carrier protein involved in seed‐specific fatty acid synthesis
Mi Chung Suh, David J. Schultz, John B. Ohlrogge (1999) · The Plant Journal
Selenite enhances arsenate toxicity in Thunbergia alata
Katharina Bluemlein, Elizabeth Klimm, Andrea Raab, Jörg Feldmann (2009) · Environmental Chemistry
cDNAs for Isoforms of the [delta]9-Stearoyl-Acyl Carrier Protein Desaturase from Thunbergia alata Endosperm
Edgar B. Cahoon, C. K. Becker, John Shanklin, John B. Ohlrogge (1994) · PLANT PHYSIOLOGY
Effects of wounding and salicylic acid on hydroxycinnamoylmalic acids in Thunbergia alata
Fatima Housti, Claude Andary, Annick Gargadennec, Mohammed Amssa (2002) · Plant Physiology and Biochemistry
Wood Anatomy of Acanthaceae: A Survey
Sherwin Carlquist, Scott Zona (1988) · Aliso
Herbal treatments in Aldai and Kaptumo divisions in Nandi district, Rift valley province, Kenya.
Pascaline Jeruto, Catherine Lukhoba, George Ouma, Dennis Otieno (2007) · PubMed
Contact Zones and Hybridization in the Jamaican Hummingbird, Trochilus polytmus (L.)
Frank B. Gill, F. Joseph Stokes, Clare Stokes (1973) · Ornithological Applications
Alatoside and thunaloside, two iridoid glucosides from Thunbergia alata
Søren Damtoft, Lotte Boe Frederiksen, Søren Rosendal Jensen (1994) · Phytochemistry

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.

Other Thunbergia 5 in the reference

History & registers

Where this page came from built 2026-09-20 · dossier v2 · node
gbif.species answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
gbif.synonyms answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
gbif.vernacular answeredcarried from build of 2026-09-19 (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 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
wikipedia answeredcarried from build of 2026-09-19; this build: skipped
inat.taxon not asked
inat.photos.wild answeredcarried from build of 2026-09-19; this build: skipped
inat.photos.cultivated nothing to reportcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
commons nothing to reportcarried 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 2026-09-19; 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 100 datasets via GBIF.org; each carries its own licence.