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Gladiolus watsonioides; photograph (c) Jared Lincenberg, some rights reserved (CC BY) CC BY(c) Jared Lincenberg, some rights reserved (CC BY) · observed growing wild · 2023-09-04

Gladiolus watsonioides Baker

Mackinders Gladiolus; Rift Gladiolus

Iridaceae · Kenya, Tanzania · listed by its genus as a bulb, tuber or caudex

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Gladiolus watsonioides, photograph (c) Jared Lincenberg, some rights reserved (CC BY)Gladiolus watsonioides, photograph (c) Jared Lincenberg, some rights reserved (CC BY)Gladiolus watsonioides, photograph (c) Jared Lincenberg, some rights reserved (CC BY)Gladiolus watsonioides, photograph (c) Jared Lincenberg, some rights reserved (CC BY)Gladiolus watsonioides, photograph (c) Jared Lincenberg, some rights reserved (CC BY)Gladiolus watsonioides, photograph (c) Jared Lincenberg, some rights reserved (CC BY) 26 photographs ›
Habitat figures
Coldest month, mean nightly low
3.4°C
Jul at the habitat, not a floor; extremes not used (the weather cell's ground is too far off) CHELSA
Warmest month, mean daily high
17°C
Feb at the habitat CHELSA
Rain a year (median across the range)
2,589mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
30–41DLI
Lowest to highest month (DLI) CHELSA
The year in the habitat's months, not shifted
  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 sharp rainy season, March to May and October to December (the habitat's months, not shifted), in a year of even temperature. rain rule, CHELSA
Not shifted: the shift rule does not apply to this habitat. The chart is in the habitat's months.

Summary

Gladiolus watsonioides is a medium to high (½–1 m), herbaceous geophyte with sword-shaped leaves, flattened in the plain of the stem, and spikes of red funnel-shaped flowers, that is assigned to the iris family. In the wild, the species is restricted to the highlands of central Kenya and northern Tanzania, including on Kilimanjaro, Mount Kenya and the Aberdare Range. It is sometimes called Mackinder's gladiolus.

Quoted from Wikipedia, "Gladiolus watsonioides", CC BY-SA 4.0.

About the genus · Gladiolus

Gladiolus is a genus of perennial cormous flowering plants in the iris family (Iridaceae).

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

Cultivation

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

Seasons

The rain rule reads a sharp season: 70% of the median year's rain (1,741 mm of 2,332 mm) falls in March to May and October to December. The temperature curve is flat, 3.8 °C between the warmest and coldest month, so the growing-season rule does not infer a growing season from it. Months are the habitat's, southern hemisphere. The habitat lies within 10° of the equator, where the shift rule does not apply, so they are not shifted for a collection elsewhere.

Rain

2,332 mm in the median year at the habitat, 1,741 mm of it March to May and October to December. Wettest month April at 521 mm, driest month September at 77 mm. Across the grid cells of the range the year's total runs 1,581 mm to 3,034 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 2,589 mm, is the year's rain at the top of the page; the 2,332 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: 30 to 41 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 27, the highest 90th-percentile month 43).

Warmth and air
Temperature

Monthly means: the coldest month's mean nightly low 3.4 °C in July (across the grid cells of the range -1.4 °C to 5.7 °C), the warmest month's mean daily high 16.6 °C in February (median year across the grid cells of the range, CHELSA). Cold floor: none read. The nearest figure is 3.4 °C, the coldest month's mean nightly low, July, 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 whose ground is too far above or below the typical spot to correct for, and are not used.

Humidity

Relative humidity at the habitat: 58 to 67% 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.

Group. Listed under the genus Gladiolus 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 Gladiolus watsonioides through the yearWarmest month February, mean daily high 17 °C; coldest month July, mean nightly low 3.4 °C; 2,332 mm of rain in the median year (the twelve monthly medians added). Medians across the range, from CHELSA. Habitat months, southern hemisphere.-5°0°5°10°15°20°frost°C · day and nightcold quarter0200400600800mm rainDLI 30–41RH 58–67%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 25 habitat cells, CHELSA cold quarter: the three months around the coldest month's mean nightly low DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C15 / 10–1717 / 11–1816 / 11–1815 / 10–1614 / 8–1613 / 7–1412 / 6–1412 / 7–1414 / 8–1614 / 9–1614 / 9–1615 / 9–16
Night °C5 / 1–85 / 2–96 / 2–97 / 3–96 / 2–85 / 0–73 / -1–64 / -1–64 / -1–65 / 0–75 / 1–85 / 1–9
Rain mm127 / 78–14194 / 71–107220 / 130–267521 / 273–786384 / 203–630115 / 64–16197 / 52–12281 / 49–14677 / 45–115155 / 103–434270 / 168–398191 / 103–219
DLI39 / 36–4041 / 39–4340 / 37–4134 / 31–3633 / 27–3731 / 27–3530 / 27–3332 / 30–3638 / 37–4139 / 37–3934 / 33–3736 / 33–37
RH %61 / 57–6558 / 55–6261 / 56–6566 / 60–7367 / 61–7465 / 58–7066 / 59–7066 / 59–6962 / 57–6664 / 59–6866 / 62–6964 / 60–67

The daily extremes were not used: the correction for elevation, +1187 m, is beyond the 1,000 m either way that a lapse rate is applied over, so the weather cell's ground is other terrain than the typical spot's. So no cold floor is read for this species, and the coldest month's mean nightly low is not taken as one. What that cell gave, so corrected, over 44 years: absolute minimum -4.0 °C, 1st-percentile night -0.3 °C.

How this section is made
Each figure is the median across the 25 grid cells holding the 75 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 1807:4333 (-0.375, 36.675). 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 25 distinct grid cells holding 75 of the 75 in-range records; extremes and elevation at the typical cell 1807:4333 (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 -0.50_36.875, lapse-corrected +1187 m at 6.5 °C/km. Elevation: ETOPO 2022, 3303 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.
NativeKenya, Tanzania · 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-0.15, 37.3 · in the densest population, 71 records (61% of those in range)
Kew's description“tuberous geophyte” · “temperate” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 116 georeferenced records inside the native range; the climate across the range on the 75 of them placed to within 10 km; the map shows only the 48 openly licensed ones, which alone would put the marker 5 km away. 41 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 116 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Gladiolus watsonioides, photograph 1did not loadGladiolus watsonioides, photograph 2did not loadGladiolus watsonioides, photograph 3did not loadGladiolus watsonioides, photograph 4did not loadGladiolus watsonioides, photograph 5did not loadGladiolus watsonioides, photograph 6did not load

Photographs: (c) Jared Lincenberg, some rights reserved (CC BY) (6).

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

Kniphofia thomsonii Kniphofia thomsonii Alpine Poker Photo: CC BY, Adrien JaillouxLobelia gregoriana Lobelia gregoriana Campanulaceae Photo: CC0, author not statedRomulea congoensis Romulea congoensis Iridaceae Photo: CC BY-SA, Susan BrownEscallonia myrtilloides Escallonia myrtilloides Escalloniaceae Photo: CC BY, Yuri SofronovCyrtochilum pardinum Cyrtochilum pardinum Leopard-flowered Orchid Photo: CC0, author not statedHypericum laricifolium Hypericum laricifolium Hypericaceae Photo: CC BY, Denis Zabin

Other Gladiolus 53 in the reference

Gladiolus alatus Gladiolus alatus Iridaceae Photo: CC BY, Cricket RaspetGladiolus anatolicus Gladiolus anatolicus Anatolian Gladiolus Photo: CC0, author not statedGladiolus angustus Gladiolus angustus Painted-lady Photo: CC BY, Justin PonderGladiolus atroviolaceus Gladiolus atroviolaceus Steppe Gladiolus Photo: CC BY, avocat Gladiolus aureus Golden Glad Gladiolus brevifolius Gladiolus brevifolius March pypie Photo: CC BY, Andrew GillespieGladiolus × byzantinus Gladiolus × byzantinus Iridaceae Photo: CC0, Robert H. WardellGladiolus candidus Gladiolus candidus Iridaceae Photo: CC BY-SA, Susan BrownGladiolus cardinalis Gladiolus cardinalis New Year-lily Photo: CC BY-SA, Tony RebeloGladiolus carinatus Gladiolus carinatus Blue Afrikaner Photo: CC BY, Charleen BrunkeGladiolus carmineus Gladiolus carmineus Hermanus gladiolus Photo: CC BY-SA, magriet bGladiolus carneus Gladiolus carneus Broadleaf painted-lady Photo: CC BY-SA, Barbara le Roux all 54 ›

Names & registers

Also known as Antholyza gracilis; Antholyza speciosa; Antholyza watsonioides; Gladiolus aberdaricus; Gladiolus garnieri and 4 more. (GBIF Backbone)

GBIFPOWOIPNIWFOWikidataWikipediaiNaturalist

The record

Family
Iridaceae
Described by
Baker
Native to
Kenya, Tanzania
Wild records
116 in range · 48 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
Habitat climate climate answeredasked 2026-10-22
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell -0.50_36.875, lapse-corrected +1187 m at 6.5 °C/km; read, and set aside: the correction for elevation, +1187 m, is beyond the 1,000 m either way that a lapse rate is applied over, so the weather cell's ground is other terrain than the typical spot's, so no cold floor is shown
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 12 datasets via GBIF.org; each carries its own licence.

Cultifolio

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