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Ixia dubia; photograph (c) Caroline Voget, some rights reserved (CC BY) CC BY(c) Caroline Voget, some rights reserved (CC BY) · observed growing wild · 2026-09-20

Ixia dubia Vent.

Yellow Kalossie; Yellow ixia

Iridaceae · Cape Provinces · listed by its family as a bulb, tuber or caudex

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Ixia dubia, photograph (c) Caroline Voget, some rights reserved (CC BY)Ixia dubia, photograph (c) Jared Zachary Herman, some rights reserved (CC BY)Ixia dubia, photograph (c) Jared Zachary Herman, some rights reserved (CC BY)Ixia dubia, photograph (c) Jared Zachary Herman, some rights reserved (CC BY)Ixia dubia, photograph (c) Caroline Voget, some rights reserved (CC BY)Ixia dubia, photograph (c) Tony Rebelo, some rights reserved (CC BY-SA) 67 photographs ›
Habitat figures
Cold floor (1 night in 100)
6.8°C
Record low 4.4 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
25°C
Feb at the habitat CHELSA
Rain a year (median across the range)
918mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
16–52DLI
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
Wet winters: the rain comes October to March (April to September at the habitat), read as a winter growing season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Ixia dubia is an Ixia species found growing in granite slopes from Piketberg to Caldon, South Africa.

Quoted from Wikipedia, "Ixia dubia", CC BY-SA 4.0.

Cultivation

Grouped as a bulb, tuber or caudex, listed under the family Iridaceae in the archetype table, and Kew describes it as “tuberous geophyte”.

Seasons

The rain rule reads a winter growing season: 70% of the median year's rain (719 mm of 927 mm) falls in April to September, cooler than the year (wet-season mean 14.0 °C against a yearly mean of 16.3 °C). Months are the habitat's, southern hemisphere; shifted six months for a northern-hemisphere collection: October to March.

Rain

927 mm in the median year at the habitat, 719 mm of it April to September. Wettest month July at 162 mm, driest month February at 25 mm. Across the grid cells of the range the year's total runs 588 mm to 1,944 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 918 mm, is the year's rain at the top of the page; the 927 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: 16 to 52 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 15, the highest 90th-percentile month 55).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 6.8 °C, the absolute minimum 4.4 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 34.9 °C. Monthly means: the coldest month's mean nightly low 8.9 °C in July (across the grid cells of the range 5.2 °C to 12.7 °C), the warmest month's mean daily high 24.7 °C in February (median year across the grid cells of the range, CHELSA). Cold floor: 6.8 °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: 59 to 61% 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 -168 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.

Group. Listed under the family Iridaceae in the archetype table, and Kew describes it as “tuberous geophyte”. A group is taken only where Kew's description of the species agrees with the table's listing. The table gives no figure and no prose; the cold floor is the habitat's alone.

Climate across the habitat

Habitat months, southern hemisphere

Habitat climate of Ixia dubia through the yearWarmest month February, mean daily high 25 °C; coldest month July, mean nightly low 8.9 °C; 927 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, southern hemisphere.0°10°20°30°40°34.9° 99th-percentile day, NASA POWER4.4° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0100200300400mm rainDLI 16–52RH 59–61%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 95 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 °C24 / 20–3125 / 20–3123 / 19–2921 / 18–2518 / 16–2116 / 15–1715 / 14–1716 / 14–1817 / 15–2019 / 16–2321 / 17–2623 / 19–29
Night °C17 / 15–1817 / 16–1816 / 14–1714 / 12–1612 / 9–1510 / 6–139 / 5–139 / 6–1310 / 7–1312 / 9–1414 / 12–1616 / 14–17
Rain mm28 / 19–6625 / 16–5035 / 25–7076 / 57–145117 / 67–256149 / 86–321162 / 92–317128 / 74–26287 / 52–19349 / 36–12739 / 27–9732 / 23–79
DLI52 / 50–5547 / 44–4938 / 35–4027 / 25–2919 / 18–2116 / 15–1717 / 16–1923 / 21–2431 / 30–3241 / 38–4249 / 46–5052 / 50–54
RH %59 / 51–6359 / 51–6460 / 52–6560 / 53–6461 / 55–6360 / 56–6159 / 57–6161 / 58–6261 / 58–6259 / 55–6259 / 53–6259 / 52–63
How this section is made
Each figure is the median across the 95 grid cells holding the 424 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 2475:3969 (-33.775, 18.475). Over 44 years there: absolute minimum 4.4 °C, 1st-percentile night 6.8 °C, 99th-percentile day 34.9 °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 95 distinct grid cells holding 424 of the 424 in-range records; extremes and elevation at the typical cell 2475:3969 (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 -34.00_18.750, lapse-corrected -168 m at 6.5 °C/km. Elevation: ETOPO 2022, 41 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.
NativeCape Provinces · 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 marker-34.097, 18.426 · in the densest population, 534 records (100% of those in range)
Kew's description“tuberous geophyte” · “subtropical” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 536 georeferenced records inside the native range; the climate across the range on the 424 of them placed to within 10 km; the map shows only the 167 openly licensed ones, which alone would put the marker 23 km away. 7 records outside the WCVP native range not used. 112 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 536 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Ixia dubia, photograph 1did not loadIxia dubia, photograph 2did not loadIxia dubia, photograph 3did not loadIxia dubia, photograph 4did not loadIxia dubia, photograph 5did not loadIxia dubia, photograph 6did not load

Photographs: (c) Caroline Voget, some rights reserved (CC BY) (2); (c) Jared Zachary Herman, some rights reserved (CC BY) (3); (c) Tony Rebelo, some rights reserved (CC BY-SA).

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

Lampranthus emarginatus Lampranthus emarginatus Clusterleaf Brightfig Photo: CC BY, Adele SLLeucadendron argenteum Leucadendron argenteum Silver Tree Photo: CC BY, Jeremy GilmoreTulbaghia alliacea Tulbaghia alliacea Trumpet Garlic Photo: CC BY, Simon TamblynPhylica pubescens Phylica pubescens Rhamnaceae Photo: CC BY, Charleen BrunkeErepsia bracteata Erepsia bracteata Bract Spoonfig Photo: CC BY-SA, Paul EmmsAmaryllis belladonna Amaryllis belladonna Jersey lily Photo: CC BY, Jonathan Juan Chancasana Villacorta

Other Ixia 6 in the reference

Ixia maculata Ixia maculata Spotted African cornlily Photo: CC BY, Arnim LittekIxia paniculata Ixia paniculata Tubular corn-lily Photo: CC BY-SA, James Deacon Ixia polystachia Iridaceae Ixia scillaris Ixia scillaris Agretjie Kalossie Photo: CC BY, Ren HoekstraIxia stricta Ixia stricta Summer Kalossie Photo: CC BY-SA, Dave UIxia viridiflora Ixia viridiflora Azure Kalossie Photo: CC BY, linkie

Names & registers

Also known as Gladiolus umbellatus; Ixia bicolorata; Ixia frederickii; Ixia polystachya var. bicolorata. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Iridaceae
Described by
Vent.
Native to
Cape Provinces
Wild records
536 in range · 167 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; 16 records within 1 km of a botanic garden, herbarium or zoo left out (11 at a botanic garden or arboretum, 1 at a herbarium, 4 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 -34.00_18.750, lapse-corrected -168 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 7 datasets via GBIF.org; each carries its own licence.

Cultifolio

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