35 photographs › At a glance
- Jan
- Feb
- Mar
- Apr
- May
- Jun, shaded
- Jul, shaded
- Aug, shaded
- Sep, shaded
- Oct, shaded
- Nov, shaded
- Dec, shaded
Summary
Bikkia tetrandra (Chamorro: gausåli) is an herbaceous member of the family Rubiaceae, distinguished by its white square-shaped flowers. It is native to Papuasia and islands of the western Pacific, including the Caroline Islands, Fiji, Mariana Islands, New Caledonia, New Guinea, Niue, Solomon Islands, Tonga, Vanuatu, and Wallis-Futuna Islands. The stems ignite easily and can be used to make torches or candles.
Quoted from Wikipedia, "Bikkia tetrandra", CC BY-SA 4.0.
Cultivation
Seasons
The rain rule reads a summer growing season: 70% of the median year's rain (1,368 mm of 1,870 mm) falls in December to June, warmer than the year (wet-season mean 25.2 °C against a yearly mean of 24.1 °C). Months are the habitat's, southern hemisphere; shifted six months for a northern-hemisphere collection: June to December.
Rain
1,870 mm in the median year at the habitat, 1,368 mm of it December to June. Wettest month March at 259 mm, driest month September at 85 mm. Across the grid cells of the range the year's total runs 1,594 mm to 2,942 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,878 mm, is the year's rain at the top of the page; the 1,870 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: 22 to 43 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 21, the highest 90th-percentile month 44).
Warmth and air
Monthly means: the coldest month's mean nightly low 21.1 °C in August (across the grid cells of the range 19.4 °C to 24.3 °C), the warmest month's mean daily high 27.3 °C in February (median year across the grid cells of the range, CHELSA). Cold floor: none read. The nearest figure is 21.1 °C, the coldest month's mean nightly low, August, in the median year (CHELSA); a month's mean of its nightly lows is warmer than the nights a floor is read from. The daily extremes were read at a weather cell that is mostly sea and are not used.
Relative humidity at the habitat: 58 to 64% 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. CHELSA monthly means, median year across the grid cells of the range. No cold floor is read without a daily extremes series; the coldest month's mean nightly low named in its sentence is not one. 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, southern hemisphere
Mean daily high from 22 °C in Aug to 27 °C in Jan, Feb and Mar; mean nightly low from 21 °C in Jul, Aug and Sep to 25 °C in Jan, Feb, Mar and Apr. The cold quarter, Jul to Sep, is the three months around the coldest month's mean nightly low, centred on the 3 months in a row that tie for it. 1,870 mm of rain in the median year (the twelve monthly medians added), the wettest month Mar. The bands show the 10th to 90th percentile across 36 habitat cells. Beneath: daily light integral and relative humidity through the year, each on its own scale.
Figures by month
| Figure | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Day °C | 27 / 26–28 | 27 / 27–28 | 27 / 27–28 | 26 / 26–28 | 25 / 24–28 | 24 / 23–27 | 23 / 22–27 | 22 / 22–27 | 23 / 23–27 | 24 / 23–27 | 25 / 24–28 | 26 / 25–28 |
| Night °C | 25 / 24–26 | 25 / 25–26 | 25 / 24–26 | 25 / 23–26 | 23 / 22–25 | 22 / 21–25 | 21 / 20–24 | 21 / 19–24 | 21 / 20–25 | 22 / 21–25 | 23 / 22–25 | 24 / 23–26 |
| Rain mm | 201 / 166–339 | 245 / 190–306 | 259 / 205–309 | 192 / 152–308 | 158 / 130–257 | 139 / 115–234 | 105 / 91–230 | 94 / 70–158 | 85 / 72–204 | 99 / 67–191 | 119 / 92–230 | 174 / 153–297 |
| DLI | 42 / 34–43 | 39 / 35–40 | 35 / 35–36 | 31 / 30–32 | 25 / 24–31 | 22 / 21–29 | 23 / 22–29 | 28 / 27–32 | 35 / 33–36 | 40 / 38–41 | 42 / 37–43 | 43 / 33–44 |
| RH % | 64 / 63–66 | 64 / 64–66 | 64 / 63–66 | 63 / 61–65 | 60 / 59–65 | 60 / 58–65 | 58 / 56–65 | 58 / 57–64 | 59 / 58–65 | 60 / 59–64 | 61 / 60–65 | 63 / 62–66 |
Records on both sides of the equator: the 16 cells at least 10° north of it have seasons six months apart and are left out, not combined into a year no place has. These figures are across the 36 cells that remain: the 31 at least 10° south and the 5 within 10° of the equator, which stay in either way.
The daily extremes were read at a NASA POWER cell that is 16% land: neither it nor the next candidates whose coldest month's mean nightly low is within 2 °C of the median across cells sit in a POWER cell that is mostly land, and the rule reads a cold floor only from a cell that is mostly land, so none is read for this species. Nor is the coldest month's mean nightly low taken as one: it is a mean of a month's lows, not its coldest night. What that cell gave over 44 years: absolute minimum 18.5 °C, 1st-percentile night 20.3 °C, 99th-percentile day 28.6 °C.
How this section is made
Natural habitat
How this section is made
Photographs
Photographs: (c) nick_goldwater, some rights reserved (CC BY); (c) Nielbert Raner, some rights reserved (CC BY) (3); (c) Kate Brown, some rights reserved (CC BY-SA); (c) Rachael Kaiser, some rights reserved (CC BY).
Related
Similar habitat climate The 6 nearest by mean daily high, mean nightly low and rain, month by month. How.
Canavalia sericea Silky jackbean Photo: CC BY, Debra Baker
Agathis macrophylla Fijian Kauri Pine Photo: CC BY, Neal Kelso
Melicope denhamii Rutaceae Photo: CC BY, Dominik Maximilián Ramík
Mimusops coriacea Mimusops Photo: CC BY, fmunoz
Pavetta opulina Rubiaceae Photo: CC BY-SA, Zoé Thivet
Fagraea berteroana Cape jitta Photo: CC BY, rainerburkardNames & registers
Also known as Bikkia australis; Bikkia australis var. commersoniana; Bikkia australis var. fosteriana; Bikkia comptonii; Bikkia forsteriana and 8 more. (GBIF Backbone)
The record
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 2026-10-21
gbif.species answeredasked 2026-10-21gbif.synonyms answeredasked 2026-10-21gbif.vernacular answeredasked 2026-10-21names fetched 2026-10-21wcvp.distribution answeredas of 2026-06-04gbif.occurrences answeredas of 2026-10-21GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21; 1 record within 1 km of a botanic garden, herbarium or zoo left out (1 at a botanic garden or arboretum; Wikidata's list)climate answeredasked 2026-10-21climate.extremes answeredasked 2026-10-21NASA POWER (MERRA-2) daily 1981–2024, cell -20.50_166.875, lapse-corrected +22 m at 6.5 °C/km; read, and set aside: NASA POWER's cell is mostly sea (16% land), so no cold floor is shownwikidata answeredasked 2026-10-21wikipedia answeredasked 2026-10-21inat.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 2026-10-22inat.photos.cultivated not askedgbif.media answeredasked 2026-10-21openalex not askednot yet asked for this reference; a later fill takes the papers from OpenAlex's snapshotEvery 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 24 datasets via GBIF.org; each carries its own licence.