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Rotheca serrata; photograph (c) swanand kesari, some rights reserved (CC BY) CC BY(c) swanand kesari, some rights reserved (CC BY) · observed growing wild · 2025-09-17

Rotheca serrata (L.) Steane & Mabb.

Blue Fountain Bush

Lamiaceae · China South-Central, China Southeast +18

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Rotheca serrata, photograph (c) Aadi Kulkarni, some rights reserved (CC BY)Rotheca serrata, photograph (c) Ravuri Krishna Chaitanya, some rights reserved (CC BY)Rotheca serrata, photograph (c) Ravuri Krishna Chaitanya, some rights reserved (CC BY)Rotheca serrata, photograph (c) Ravuri Krishna Chaitanya, some rights reserved (CC BY)Rotheca serrata, photograph (c) Ravuri Krishna Chaitanya, some rights reserved (CC BY)Rotheca serrata, photograph (c) Ramesh Shenai, some rights reserved (CC BY) 75 photographs ›
Habitat figures
Cold floor (1 night in 100)
10.8°C
Record low 7.0 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
33°C
Apr at the habitat CHELSA
Rain a year (median across the range)
2,321mm
7 months of 25 mm or more in the median year CHELSA
Open-sky light
23–44DLI
Lowest to highest month (DLI) CHELSA
The year in your months, northern hemisphere
  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec
A rainy season, June to September, neither the cool nor the warm half of the year. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Rotheca serrata, commonly known as the blue fountain bush, the blue-flowered glory tree or the beetle killer, is a species of flowering plants in the family Lamiaceae. It is native to India, Sri Lanka and Malaysia.

Quoted from Wikipedia, "Rotheca serrata", CC BY-SA 4.0.

About the genus · Rotheca

Rotheca is a genus of flowering plants in the family Lamiaceae. Estimates of the number of species in the genus vary from about 35 to as many as 60. Three of the species are native to tropical Asia, with the rest occurring in Sub-Saharan Africa. More on Wikipedia ›

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

Cultivation

Seasons

The rain rule reads a rainy season with no name: 70% of the median year's rain (1,480 mm of 1,801 mm) falls in June to September, whose mean temperature, 24.1 °C, is within half a degree of the year's, 24.0 °C, so it is neither the cooler nor the warmer part of the year. Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: December to March.

Rain

1,801 mm in the median year at the habitat, 1,480 mm of it June to September. Wettest month July at 509 mm, driest months (2 at 2 mm); 2 months under 5 mm. Across the grid cells of the range the year's total runs 970 mm to 4,175 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 2,321 mm, is the year's rain at the top of the page; the 1,801 mm here is the median year's, the twelve monthly medians added, which the rain rule reads. Habitat calendar, northern hemisphere; median year across the grid cells of the range, CHELSA.

Light

Open sky over the habitat: 23 to 44 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 19, the highest 90th-percentile month 46).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 10.8 °C, the absolute minimum 7.0 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 38.7 °C. Monthly means: the coldest month's mean nightly low 14.9 °C in January (across the grid cells of the range 12.4 °C to 21.9 °C), the warmest month's mean daily high 32.9 °C in April (median year across the grid cells of the range, CHELSA). Cold floor: 10.8 °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: 51 to 72% 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 +9 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.

Climate across the habitat

Habitat months, northern hemisphere

Habitat climate of Rotheca serrata through the yearWarmest month April, mean daily high 33 °C; coldest month January, mean nightly low 14.9 °C; 1,801 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, northern hemisphere.0°10°20°30°40°38.7° 99th-percentile day, NASA POWER7.0° lowest night in 44 years, NASA POWER°C · day and nightcold quarter050010001500mm rainDLI 23–44RH 51–72%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 263 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 / 24–3130 / 26–3232 / 28–3433 / 28–3632 / 28–3528 / 25–3127 / 24–2926 / 23–2927 / 25–2928 / 25–3028 / 24–3127 / 23–31
Night °C15 / 12–2216 / 14–2219 / 16–2421 / 19–2522 / 20–2622 / 19–2621 / 19–2521 / 18–2421 / 18–2420 / 17–2417 / 15–2315 / 13–22
Rain mm2 / 1–1362 / 0–7811 / 2–10624 / 4–17584 / 28–249294 / 87–961509 / 95–1370393 / 118–952284 / 141–463152 / 95–29637 / 20–2519 / 5–204
DLI35 / 29–3739 / 34–4143 / 36–4444 / 36–4641 / 32–4429 / 24–3323 / 19–3224 / 19–3329 / 26–3432 / 28–3432 / 27–3332 / 27–34
RH %53 / 47–6551 / 45–6351 / 43–6255 / 46–6661 / 55–6769 / 62–7672 / 64–8271 / 65–8169 / 64–7563 / 56–6957 / 50–6854 / 48–66
How this section is made
Each figure is the median across the 263 grid cells holding the 335 in-range records, 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 1542:5150 (12.875, 77.525). Over 44 years there: absolute minimum 7.0 °C, 1st-percentile night 10.8 °C, 99th-percentile day 38.7 °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 263 distinct grid cells holding 335 of the 335 in-range records; extremes and elevation at the typical cell 1542:5150 (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 13.00_77.500, lapse-corrected +9 m at 6.5 °C/km. Elevation: ETOPO 2022, 851 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.
NativeChina South-Central, China Southeast, Tibet, Assam, Bangladesh, East Himalaya, India, Nepal, Pakistan, Sri Lanka, West Himalaya, Cambodia, Laos, Myanmar, Thailand, Vietnam, Borneo, Jawa, Malaya, Sumatera · introduced: Seychelles · 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 marker18.254, 73.707 · in the densest population, 131 records (23% of those in range)
Kew's description“shrub” · “wet tropical” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 567 georeferenced records inside the native range; the climate across the range on the 335 of them placed to within 10 km; the map shows only the 316 openly licensed ones, which alone would put the marker 705 km away. 16 records outside the WCVP native range not used. 232 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 567 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Rotheca serrata, photograph 1did not loadRotheca serrata, photograph 2did not loadRotheca serrata, photograph 3did not loadRotheca serrata, photograph 4did not loadRotheca serrata, photograph 5did not loadRotheca serrata, photograph 6did not load

Photographs: (c) Aadi Kulkarni, some rights reserved (CC BY); (c) Ravuri Krishna Chaitanya, some rights reserved (CC BY) (4); (c) Ramesh Shenai, some rights reserved (CC BY).

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

Dalbergia latifolia Dalbergia latifolia Indian rosewood Photo: CC BY, Ravuri Krishna ChaitanyaDiospyros montana Diospyros montana Bombay Ebony Photo: CC BY, SahajaPavetta indica Pavetta indica Indian pavetta Photo: CC BY, Ravuri Krishna ChaitanyaTerminalia chebula Terminalia chebula Myrobalan Photo: CC BY-SA, Dinesh ValkeFicus amplissima Ficus amplissima Indian Bat Fig Photo: CC BY, rajesh rockySapindus trifoliatus Sapindus trifoliatus Threeleaf soapberry Photo: CC BY, renjus box

Other Rotheca 3 in the reference

Rotheca hirsuta Rotheca hirsuta Butterfly Bush Photo: CC BY, Sunčana BradleyRotheca microphylla Rotheca microphylla Musical Note Photo: CC BY, Ashwin ARotheca myricoides Rotheca myricoides Cats-whiskers Photo: CC BY, Jacek Pietruszewski

Names & registers

Also known as Clerodendrum bracteosum; Clerodendrum cuneatum; Clerodendrum divaricatum; Clerodendrum farinosum; Clerodendrum farinosum var. pubescens and 32 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Lamiaceae
Described by
(L.) Steane & Mabb.
Native to
China South-Central, China Southeast, Tibet +17
Wild records
567 in range · 316 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; 2 records within 1 km of a botanic garden, herbarium or zoo left out (1 at a herbarium, 1 at a zoo; 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 13.00_77.500, lapse-corrected +9 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22
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
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 38 datasets via GBIF.org; each carries its own licence.

Cultifolio

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