no rights reserved · observed growing wild · 2006-03-11

Romulea clusiana (Lange) Nyman

Iridaceae

Climate known 32 photographs Bulb, tuber or caudex

Every figure on this page is derived from public data by a stated rule and says its source; nothing here is written by a person or a model, except the Wikipedia passage, which is quoted and marked as such. How it is made.

About the genus · Romulea

Romulea is a genus of flowering plants in the family Iridaceae, first described as a genus in 1772. It is found in Europe, the Mediterranean, the Arabian Peninsula, and Africa.

Text from Wikipedia, “Romulea”, CC BY-SA 4.0, quoted as written.

Family

Iridaceae

Described by

(Lange) Nyman

Native to

Portugal, Spain, Algeria +1

Wild records

300 in range· 32 open

At a glance

Warmest month

23°C

Aug, mean day; nights 17 °C (CHELSA)

Rain

1462mm/yr

12 wet months · peak Dec 211 mm (CHELSA)

Light

10–44DLI

mol/m²/day, winter to summer, open sky (CHELSA shortwave)

In short condensed by rule from the cultivation cards · not written by a person

Grouped as a bulb, tuber or caudex by the genus Romulea, which is reliably one kind of plant (archetype table). Rain rule: a winter growing season, October to April in the northern hemisphere (October to April at the habitat, northern). Habitat rain 1462 mm a year, wettest December at 211 mm, driest July at 36 mm (habitat calendar, northern hemisphere). Open sky over the habitat: 10 to 44 mol/m²/day. Cold floor 1.2 °C (1st-percentile habitat night, NASA POWER).

Each sentence is one card's own one-line form, written by the same rule as the card (Its year, Rain, Light, Temperature); the note cannot say what a card does not. Months are given for the northern hemisphere (set your site in Settings to change this), and the habitat's own alongside. The cards · the figures.

Also known as Bulbocodium clusianum (Lange) Kuntze; Ixia bulbocodium var. major Schousb.; Romulea bulbocodium subsp. clusiana (Lange) Cout.; Romulea bulbocodium var. clusiana (Lange) Batt.; Romulea bulbocodium var. major (Schousb.) Maire & Weiller and 8 more.

Cultivation

Grouped as a bulb, tuber or caudex by the genus Romulea, which is reliably one kind of plant (archetype table). The table holds no figure for this group, which spans too much for one minimum; the cold floor is the habitat's alone, and no prose comes from the table.

Its year Rain rule: a winter growing season, October to April in the northern hemisphere (October to April at the habitat, northern).

This species’ habitat figures, and what two fixed rules read from them.

The rain rule reads a winter growing season: 70% of the year's rain (1133 mm of 1462 mm) falls in October to April, cooler than the year (wet-season mean 12.6 °C against a yearly mean of 14.8 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: April to October.

Read from the median year of CHELSA monthly rainfall and mean temperature across the envelope cells: 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 gives a season to reverse. A reading of the curves, not an observation of the plant.

Rain Habitat rain 1462 mm a year, wettest December at 211 mm, driest July at 36 mm (habitat calendar, northern hemisphere).

This species’ habitat figures, with their source.

1462 mm a year at the habitat, 1133 mm of it October to April. Wettest month December at 211 mm, driest July at 36 mm. Across the envelope cells the year's total runs 664 mm to 1882 mm (10th to 90th percentile of each cell's own year) (median year across the envelope cells, CHELSA; habitat calendar, northern hemisphere).

CHELSA monthly precipitation, median year across the envelope cells. The rain that falls where the species is recorded; nothing about how the plant takes water.

Light Open sky over the habitat: 10 to 44 mol/m²/day.

This species’ habitat figures, with their source.

Open sky over the habitat: 10 to 44 mol/m²/day across the year (daily light integral, median year across the envelope cells, CHELSA; the lowest 10th-percentile month across the cells is 9, the highest 90th-percentile month 50).

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.

Warmth and air Cold floor 1.2 °C (1st-percentile habitat night, NASA POWER).

This species’ habitat figures, with their source.

Temperature

Coldest: the 1st-percentile night over 44 years at the typical cell is 1.2 °C, the absolute minimum -1.7 °C, about 1 frost night a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 33.0 °C. Monthly means: coldest night 8.1 °C in January (across the envelope cells 2.7 °C to 10.5 °C), warmest day 22.7 °C in August (median year across the envelope cells, CHELSA). Cold floor: 1.2 °C, which is the 1st-percentile night over 44 years at the typical cell (NASA POWER).

NASA POWER daily minima and maxima 1981–2024 at the typical cell, without lapse correction; CHELSA monthly means, median year across the envelope cells, CHELSA. The cold floor is the figure named in its sentence. Not a measured survival limit for any plant in a pot.

Humidity

Relative humidity at the habitat: 61 to 64% across the year (monthly means, median year across the envelope cells, CHELSA). A figure about the air, saying nothing about how the plant takes water.

CHELSA relative humidity, median year across the envelope cells.

The figures the cards read from are in Climate below, and where they came from in Natural habitat.

Climate across the habitat

day night rain 10th–90th percentile across 161 habitat cells cold quarter: the three months around the coldest night extremes over 44 years at the typical cell, marked at the edge: undated DLI, mol/m²/dayRH %each on its own scale

Figures by month

	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Day °C	13 / 10–15	13 / 11–15	15 / 13–17	15 / 14–18	18 / 16–21	21 / 19–24	22 / 20–27	23 / 21–27	21 / 20–25	18 / 17–22	15 / 13–18	13 / 11–16
Night °C	8 / 3–11	8 / 3–11	9 / 5–12	10 / 6–13	12 / 10–15	15 / 13–18	16 / 15–20	17 / 15–21	16 / 14–20	14 / 10–17	11 / 6–14	9 / 4–12
Rain mm	169 / 85–230	131 / 68–174	118 / 53–163	128 / 57–157	105 / 30–140	55 / 8–69	36 / 2–47	42 / 4–54	91 / 25–114	183 / 75–246	193 / 108–242	211 / 126–288
DLI	11 / 10–18	17 / 16–23	26 / 24–33	34 / 31–40	39 / 36–45	44 / 41–50	44 / 40–50	39 / 36–45	30 / 28–36	19 / 18–26	12 / 11–19	10 / 9–15
RH %	62 / 60–65	62 / 59–64	61 / 58–63	62 / 58–64	63 / 57–65	62 / 56–66	63 / 54–67	63 / 56–67	63 / 58–66	64 / 60–66	63 / 61–66	63 / 60–65

Each figure is the median across the 161 grid cells holding the 293 in-range records, with the 10th–90th percentile span across those cells after the slash where it differs. Extremes and elevation were read at the typical cell 949:3421 (42.525, -8.925). Over 44 years there: absolute minimum -1.7 °C, 1st-percentile night 1.2 °C, 99th-percentile day 33.0 °C. Normals: CHELSA V2.1 1981–2010 climatology, 0.05° cells (each the mean of ~36 1 km pixels). Envelope: median and 10th–90th percentile of each month across the 161 distinct grid cells holding the 293 in-range records; extremes and elevation at the typical cell 949:3421 (its coldest month's mean night nearest the median across cells); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell 42.50_-8.750, no lapse correction (no cell elevation on file).

Natural habitat

Native range as published by WCVP; the marker is where the records are densest and decides nothing: the climate was read across every in-range record's cell, not at the marker.

Openly licensed records inside the range, framed on where they fall.

NativePortugal, Spain, Algeria, Morocco

Kew's description“tuberous geophyte” · “subtropical”· quoted from WCVP, RBG Kew (CC BY 4.0); not derived here

Map marker42.5, -8.82 · in the densest population, 203 records (68% of those in range)

Evidence usedThe map marker and the climate envelope rest on all 300 georeferenced records inside the native range; the map shows only the 32 openly licensed ones, which alone would put the marker 9 km away. 3 records outside the range (gardens, roadsides, misidentifications) ignored. 7 in-range records are placed to worse than 10 km and stay on the map but off the climate.

The map markerthe map marker: the openly licensed record nearest the middle of the densest 1° population of the 300 in-range records; it decides nothing.

Photographs

Photographs: no rights reserved · CC0 (4); (c) Diego González Dopico, some rights reserved (CC BY); (c) Gregory Wada, some rights reserved (CC BY); (c) franciscodocampo, some rights reserved (CC BY); (c) Óscar Sampedro, some rights reserved (CC BY).

Photographs: iNaturalist did not answer when this page was built; what is shown came from the sources that did.

Papers naming this species

Works whose title or abstract names Romulea clusiana, most cited first, from OpenAlex (CC0). A mention, not a cultivation source: nothing on this page is drawn from them.

Cytotaxonomy of Spanish plants. II. Monocotyledons

Áskell Löve, Ebbe Kjellqvist (1973) · LA Referencia (Red Federada de Repositorios Institucionales de Publicaciones Científicas)

Occurrence Download

GBIF.org User (2026) · Global Biodiversity Information Facility

Romulea clusiana (Lange) Nyman