

At a glance
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
From few records: 15 records in 4 grid cells. The records.
Summary
Hibiscus insularis, the Phillip Island hibiscus, is a species of flowering plant in the mallow family Malvaceae, that is endemic to Phillip Island, a small island to the south of Norfolk Island, South Pacific. The entire natural extent of this species is just two small clumps, and each clump apparently consists of multiple separate stems of a single genotype. It has been propagated and planted more widely on Phillip Island, but only vegetatively which does not increase the genetic diversity. Seedlings apparently have not been observed in the wild. More on Wikipedia ›
Quoted from Wikipedia, "Hibiscus insularis", CC BY-SA 4.0.
About the genus · Hibiscus
Hibiscus is a genus of plants in the family Malvaceae native to the tropics and subtropics. The genus is quite large, comprising 319 species. Hibiscus are renowned for their large, showy flowers and those species are commonly known simply as "hibiscus", or less widely known as rose mallow. More on Wikipedia ›
Quoted from Wikipedia, "Hibiscus", CC BY-SA 4.0.
Cultivation
Seasons
The rain rule reads no short rainy season: 70% of the median year's rain (886 mm of 1,221 mm) takes 8 months, March to August and November to December. Mean temperature moves 5.6 °C between the warmest and coldest month. Months are the habitat's, southern hemisphere; shifted six months for a northern-hemisphere collection: September to February and May to June.
Rain
1,221 mm in the median year at the habitat, 886 mm of it March to August and November to December. Wettest months (2 at 128 mm), driest month October at 70 mm. Across the grid cells of the range the year's total runs 1,188 mm to 1,299 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 1,218 mm, is the year's rain at the top of the page; the 1,221 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: 17 to 44 mol/m²/day across the year (daily light integral, median year across the grid cells of the range, CHELSA).
Warmth and air
Monthly means: the coldest month's mean nightly low 16.1 °C in August (across the grid cells of the range 16.0 °C to 16.3 °C), the warmest month's mean daily high 23.0 °C in February (median year across the grid cells of the range, CHELSA). Cold floor: none read. The nearest figure is 16.1 °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: 57 to 63% 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
From few records: this habitat climate is read from 15 records in 4 grid cells; a page says so under 12 records or 5 cells, and shows the figures as read.
Habitat months, southern hemisphere
Mean daily high from 18 °C in Jul, Aug and Sep to 23 °C in Jan, Feb and Mar; mean nightly low from 16 °C in Aug to 22 °C in Jan and Feb. The cold quarter, Jul to Sep, is the three months around the coldest month's mean nightly low. 1,221 mm of rain in the median year (the twelve monthly medians added), the wettest months (2 at 128 mm). The bands show the 10th to 90th percentile across 4 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 | 23 / 22–23 | 23 / 23–23 | 23 / 22–23 | 22 / 21–22 | 20 / 20–20 | 19 / 19–19 | 18 / 18–18 | 18 / 17–18 | 18 / 18–18 | 19 / 19–19 | 20 / 20–20 | 22 / 21–22 |
| Night °C | 22 / 21–22 | 22 / 22–22 | 21 / 21–22 | 20 / 20–21 | 19 / 19–19 | 18 / 17–18 | 17 / 16–17 | 16 / 16–16 | 17 / 17–17 | 18 / 17–18 | 19 / 19–19 | 20 / 20–21 |
| Rain mm | 82 / 79–88 | 90 / 87–97 | 94 / 91–101 | 116 / 112–125 | 118 / 115–125 | 128 / 125–136 | 128 / 126–135 | 102 / 100–107 | 93 / 92–98 | 70 / 68–75 | 94 / 91–100 | 106 / 103–113 |
| DLI | 44 / 43–44 | 40 / 40–40 | 34 / 34–34 | 27 / 27–27 | 21 / 21–21 | 17 / 17–17 | 19 / 19–19 | 24 / 24–25 | 32 / 32–32 | 39 / 38–39 | 43 / 42–43 | 44 / 44–44 |
| RH % | 63 / 61–64 | 62 / 61–63 | 61 / 60–62 | 60 / 59–61 | 58 / 57–59 | 58 / 57–58 | 57 / 56–58 | 57 / 56–57 | 58 / 57–59 | 59 / 58–59 | 60 / 59–60 | 62 / 61–63 |
The daily extremes were read at a NASA POWER cell that is 0% 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 13.1 °C, 1st-percentile night 15.2 °C, 99th-percentile day 24.5 °C.
How this section is made
Natural habitat
How this section is made
Photographs
Photographs: (c) naturewatchwidow, some rights reserved (CC BY) (2); Melburnian, CC BY 2.5, via Wikimedia Commons; Tatiana Gerus from Brisbane, Australia, CC BY 2.0, via Wikimedia Commons (2); Krzysztof Ziarnek, Kenraiz, CC BY-SA 4.0, via Wikimedia Commons.
Related
Similar habitat climate The 6 nearest by mean daily high, mean nightly low and rain, month by month. How.
Asplenium dimorphum Three-in-one fern Photo: CC BY, Sue Carnahan
Araucaria heterophylla Norfolk Island pine Photo: CC BY, naturewatchwidow
Sphaeropteris excelsa Norfolk tree fern Photo: CC0, author not stated
Alyxia gynopogon Apocynaceae Photo: CC BY-SA, bushmanjim
Rhopalostylis baueri Kermadec Five Finger Photo: CC0, author not statedOther Hibiscus 54 in the reference
Hibiscus aethiopicus Cape Hibiscus Photo: CC BY, Martjie Fia Fourie Hibiscus aridicola Malvaceae
Hibiscus arnottianus White Molokai Hibiscus Photo: CC0, author not stated
Hibiscus biseptus Arizona rose-mallow Photo: CC BY, Jose Luis Leon de la Luz
Hibiscus calyphyllus Lemonyellow rosemallow Photo: CC0, author not stated
Hibiscus clayi Clay's hibiscus Photo: CC0, author not stated
Hibiscus coccineus Scarlet rose-mallow Photo: CC0, author not stated
Hibiscus coulteri Desert rose-mallow Photo: CC BY, Ulises Pinedo all 55 ›Names & registers
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 2026-10-22
gbif.species answeredasked 2026-10-22gbif.synonyms answeredasked 2026-10-22gbif.vernacular answeredasked 2026-10-22names fetched 2026-10-22wcvp.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; 11 records within 1 km of a botanic garden, herbarium or zoo left out (6 at a botanic garden or arboretum, 2 at a herbarium, 3 at a zoo; Wikidata's list)climate answeredasked 2026-10-22climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell -29.00_168.125, lapse-corrected +70 m at 6.5 °C/km; read, and set aside: NASA POWER's cell is mostly sea (0% land), so no cold floor is shownwikidata answeredasked 2026-10-22wikipedia answeredasked 2026-10-22inat.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 2026-10-22commons answeredasked 2026-10-22openalex 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 6 datasets via GBIF.org; each carries its own licence.

