Species
+

Oxalis triangularis A.St.-Hil.

Wood sorrel, azedinha, false shamrock, purple shamrock

Climate known 48 photographs Bulb, tuber or caudex
Add one to my plants Sow seed

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.

Summary

Oxalis triangularis, commonly called false shamrock, is a species of perennial plant in the family Oxalidaceae. It is native to several countries in southern South America. This woodsorrel is typically grown as a houseplant but can be grown outside in USDA climate zones 8a–11, preferably in light shade.

Text from Wikipedia, “Oxalis triangularis”, CC BY-SA 4.0, quoted as written. Kept separate from everything derived here.

About the genus · Oxalis

Oxalis is a large genus of flowering plants in the wood-sorrel family, Oxalidaceae, comprising over 550 species. The genus occurs throughout most of the world, except for the polar areas; species diversity is particularly rich in tropical Brazil, Mexico, and South Africa.

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

Family
Oxalidaceae
Described by
A.St.-Hil.
Native to
Bolivia, Peru, Brazil West-Central +7
Wild records
465 in range· 283 open

At a glance

Warmest month
28°C
Jan, mean day; nights 20 °C (CHELSA)
Rain
1435mm/yr
12 wet months · peak Jan 200 mm (CHELSA)
Light
21–38DLI
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 Oxalis, which is reliably one kind of plant (archetype table). Rain rule: a summer growing season, April to October in the northern hemisphere (October to April at the habitat, southern). Habitat rain 1435 mm a year, wettest January at 200 mm, driest August at 45 mm (habitat calendar, southern hemisphere). Open sky over the habitat: 21 to 38 mol/m²/day. Cold floor 2.7 °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 Oxalis triangularis var. lepida Progel.

Cultivation

Grouped as a bulb, tuber or caudex by the genus Oxalis, 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 summer growing season, April to October in the northern hemisphere (October to April at the habitat, southern).

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

The rain rule reads a summer growing season: 70% of the year's rain (1095 mm of 1435 mm) falls in October to April, warmer than the year (wet-season mean 23.1 °C against a yearly mean of 20.9 °C). Months are the habitat's, southern hemisphere; shifted six months for a northern-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 1435 mm a year, wettest January at 200 mm, driest August at 45 mm (habitat calendar, southern hemisphere).

This species’ habitat figures, with their source.

1435 mm a year at the habitat, 1095 mm of it October to April. Wettest month January at 200 mm, driest August at 45 mm. Across the envelope cells the year's total runs 920 mm to 2028 mm (10th to 90th percentile of each cell's own year) (median year across the envelope cells, CHELSA; habitat calendar, southern 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: 21 to 38 mol/m²/day.

This species’ habitat figures, with their source.

Open sky over the habitat: 21 to 38 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 16, the highest 90th-percentile month 43).

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 2.7 °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 2.7 °C, the absolute minimum -2.3 °C, 28 frost nights in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 36.5 °C. Monthly means: coldest night 12.3 °C in July (across the envelope cells 7.8 °C to 20.1 °C), warmest day 28.2 °C in January (median year across the envelope cells, CHELSA). Cold floor: 2.7 °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, lapse-corrected to its elevation; 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: 59 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

Habitat climate through the yearMean day from 21 °C in Jul to 28 °C in Jan; mean night from 12 °C in Jul to 20 °C in Jan. The cold quarter, Jun to Aug, is the three months around the coldest night. 1435 mm of rain a year, most in Jan. The bands show the 10th to 90th percentile across 360 habitat cells. Over 44 years at the typical cell the absolute minimum was -2.3 °C and the 99th-percentile day 36.5 °C; neither is dated to a month. Beneath: daily light integral and relative humidity through the year, each on its own scale.-10°10°20°30°40°frost36.5° 99th-percentile day (undated)-2.3° lowest night in 44 yrs (undated)°C · day and nightcold quarter050100150200250300mm rainDLI 21–38RH 59–64 %JanFebMarAprMayJunJulAugSepOctNovDec
day night rain 10th–90th percentile across 360 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
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C28 / 25–3128 / 25–3128 / 24–3026 / 21–2923 / 18–2921 / 17–2921 / 16–2924 / 18–3025 / 19–3126 / 21–3127 / 23–3128 / 24–31
Night °C20 / 17–2320 / 17–2320 / 16–2318 / 13–2215 / 11–2213 / 9–2112 / 8–2013 / 9–2115 / 10–2217 / 12–2218 / 15–2319 / 16–23
Rain mm200 / 93–292173 / 101–240157 / 118–253116 / 72–218102 / 30–17461 / 13–14952 / 8–14545 / 7–11180 / 11–164126 / 19–210145 / 22–205178 / 62–249
DLI37 / 32–4237 / 32–4033 / 29–3628 / 23–3323 / 19–3121 / 16–3123 / 17–3228 / 22–3631 / 26–4035 / 31–4238 / 33–4338 / 33–43
RH %64 / 58–6964 / 60–7064 / 60–6964 / 60–6963 / 59–6863 / 57–6761 / 55–6659 / 53–6560 / 54–6661 / 56–6761 / 57–6863 / 58–68

Each figure is the median across the 360 grid cells holding the 454 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 2320:2520 (-26.025, -53.975). Over 44 years there: absolute minimum -2.3 °C, 1st-percentile night 2.7 °C, 99th-percentile day 36.5 °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 360 distinct grid cells holding the 454 in-range records; extremes and elevation at the typical cell 2320:2520 (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 -26.00_-53.750, lapse-corrected -105 m at 6.5 °C/km. Elevation: ETOPO 2022, 388 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 every in-range record's cell, not at the marker.
Openly licensed records inside the range, framed on where they fall.
NativeBolivia, Peru, Brazil West-Central, Brazil Northeast, Brazil Southeast, Brazil North, Brazil South, Argentina Northeast, Argentina Northwest, Paraguay· introduced: Arkansas, Florida, Louisiana
Kew's description“tuberous geophyte” · “seasonally dry tropical”· quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Map marker-25.67, -54.449 · in the densest population, 203 records (44% of those in range)
Evidence usedThe map marker and the climate envelope rest on all 465 georeferenced records inside the native range; the map shows only the 283 openly licensed ones, which alone would put the marker 22 km away. 1169 records outside the range (gardens, roadsides, misidentifications) ignored. 11 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 inside the densest 4° block of the 465 in-range records; it decides nothing.

Photographs

Oxalis triangularisOxalis triangularisOxalis triangularisOxalis triangularisOxalis triangularisOxalis triangularisOxalis triangularisOxalis triangularis

Photographs: (c) Patrícia Mees, some rights reserved (CC BY) (2); (c) Jagdish Supekar, some rights reserved (CC BY) (6).

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 Oxalis triangularis, most cited first, from OpenAlex (CC0). A mention, not a cultivation source: nothing on this page is drawn from them.

Anthocyanins from Oxalis triangularis as potential food colorants
E. Alexandra Pazmiño-Durán, M. Mónica Giusti, Ronald E. Wrolstad, Maria Beatriz Abreu Glória (2001) · Food Chemistry
Melanogenesis Inhibitory Effect of Fatty Acid Alkyl Esters Isolated from Oxalis triangularis
Sungran Huh, Young Soo Kim, Eunsun Jung, Jihee Lim (2010) · Biological and Pharmaceutical Bulletin
Antioxidant and ammonia-sensitive films based on starch, κ-carrageenan and Oxalis triangularis extract as visual indicator of beef meat spoilage
Changxing Jiang, Tingting Liu, Siyu Wang, Yufei Zou (2023) · International Journal of Biological Macromolecules
Impact of Leaf Traits on Temporal Dynamics of Transpired Oxygen Isotope Signatures and Its Impact on Atmospheric Vapor
Maren Dubbert, Angelika Kübert, Christiane Werner (2017) · Frontiers in Plant Science
Acylated anthocyanins from leaves of Oxalis triangularis
Torgils Fossen, Saleh Rayyan, Maya H. Holmberg, Ha ̊vard S. Nateland (2005) · Phytochemistry
Flavone C-Glycosides from Leaves of Oxalis triangularis
Saleh Rayyan, Torgils Fossen, Øyvind M. Andersen (2005) · Journal of Agricultural and Food Chemistry
Covalent anthocyanin–flavone dimer from leaves of Oxalis triangularis
Torgils Fossen, Saleh Rayyan, Maya H. Holmberg, Manfred Nimtz (2006) · Phytochemistry
Transcription and Metabolism Pathways of Anthocyanin in Purple Shamrock (Oxalis triangularis A.St.-Hil.)
Baobing Luo, Liujun Chen, Guoping Chen, Yunshu Wang (2022) · Metabolites
Triangular Regulation of Cucurbit[8]uril 1:1 Complexes
Sébastien Combes, Khoa Truong Tran, Mehmet Menaf Ayhan, Hakim Karoui (2019) · Journal of the American Chemical Society

Similar habitat climate the 6 species whose habitat climate is nearest this one's: mean day and night, month by month, and rain on a log scale, in calendar order, so a habitat with the same seasons six months out is far, not near. Nothing else counts: not range, not family.

Other Oxalis 7 in the reference

History & registers

Where this page came from built 2026-09-20 · dossier v2 · node
gbif.species answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
gbif.synonyms answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
gbif.vernacular answeredcarried from build of 2026-09-19 (offline re-derivation; the backbone was not asked)
wcvp.distribution answered
gbif.occurrences answeredGBIF occurrence download https://doi.org/10.15468/dl.3h4zam
climate answered
wikidata answeredcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
wikipedia answeredcarried from build of 2026-09-19; this build: skipped
inat.taxon not asked
inat.photos.wild answeredcarried from build of 2026-09-19; this build: skipped
inat.photos.cultivated nothing to reportcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
commons nothing to reportcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
gbif.media answered
openalex answeredcarried from build of 2026-09-19; this build: skipped

Every upstream is recorded as having answered, reported nothing, or refused. Only “nothing to report” is ever shown as an absence. Records came from 102 datasets via GBIF.org; each carries its own licence.