Barleria obtusa, Bo Plaas, Baviaans, Western District, South Africa

Barleria obtusa Nees

Blue Bushviolet, Bush Violet, South Coast Bush Violet, بارليريا اوبتوزا

Climate known 69 photographs

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

Barleria obtusa, the bush violet, is a species of flowering plant in the family Acanthaceae. It occurs naturally along forest margins in the summer rainfall region of South Africa and in Mozambique. It is widely cultivated as a decorative garden shrub.

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

About the genus · Barleria

Barleria is a genus of plants in the family Acanthaceae. It includes 303 species native to the tropics and subtropics, including the Americas from Mexico to northern South America, sub-Saharan Africa, Egypt and the Arabian Peninsula, the Indian subcontinent, Indochina, southern China and Taiwan, parts of Malesia, and New Guinea.

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

Family

Acanthaceae

Described by

Nees

Native to

Mozambique, KwaZulu-Natal, Free State +1

Wild records

642 in range· 207 open

At a glance

Warmest month

27°C

Jan, mean day; nights 18 °C (CHELSA)

Rain

781mm/yr

8 wet months · peak Jan 128 mm (CHELSA)

Light

23–39DLI

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

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

Rain rule: a summer growing season, May to September in the northern hemisphere (November to March at the habitat, southern). Habitat rain 781 mm a year, wettest January at 128 mm, driest July at 11 mm (habitat calendar, southern hemisphere). Open sky over the habitat: 23 to 39 mol/m²/day. Cold floor 5.5 °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 Barleria obtusa var. cymulosa Hochst.; Barleria uitenagensis Hochst.; Barleria uitenagensis Hochst. ex Nees.

Cultivation

Its year Rain rule: a summer growing season, May to September in the northern hemisphere (November to March 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 (561 mm of 781 mm) falls in November to March, warmer than the year (wet-season mean 22.5 °C against a yearly mean of 19.3 °C). Months are the habitat's, southern hemisphere; shifted six months for a northern-hemisphere collection: May to September.

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 781 mm a year, wettest January at 128 mm, driest July at 11 mm (habitat calendar, southern hemisphere).

This species’ habitat figures, with their source.

781 mm a year at the habitat, 561 mm of it November to March. Wettest month January at 128 mm, driest July at 11 mm. Across the envelope cells the year's total runs 623 mm to 1072 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: 23 to 39 mol/m²/day.

This species’ habitat figures, with their source.

Open sky over the habitat: 23 to 39 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 20, the highest 90th-percentile month 44).

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 5.5 °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 5.5 °C, the absolute minimum 1.1 °C, no frost in 44 years (NASA POWER daily minima). Warmest: the 99th-percentile day is 37.8 °C. Monthly means: coldest night 8.0 °C in July (across the envelope cells 3.3 °C to 14.9 °C), warmest day 26.9 °C in January (median year across the envelope cells, CHELSA). Cold floor: 5.5 °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: 54 to 61% 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 350 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	27 / 25–30	27 / 25–30	26 / 24–29	24 / 22–27	23 / 20–25	21 / 17–23	21 / 18–23	22 / 20–25	24 / 22–27	25 / 22–27	25 / 23–28	26 / 24–29
Night °C	18 / 15–22	18 / 15–22	17 / 14–22	15 / 11–20	11 / 7–18	8 / 4–15	8 / 3–15	10 / 6–16	12 / 9–17	14 / 11–18	16 / 13–19	18 / 15–21
Rain mm	128 / 109–143	114 / 88–142	91 / 75–114	44 / 33–71	18 / 12–47	15 / 7–39	11 / 3–41	20 / 6–48	32 / 15–80	80 / 55–112	110 / 88–132	118 / 93–136
DLI	39 / 36–43	37 / 35–41	33 / 31–36	28 / 27–32	25 / 23–28	23 / 20–25	24 / 21–27	27 / 25–32	32 / 29–39	33 / 31–41	36 / 34–42	39 / 36–44
RH %	61 / 56–66	61 / 56–66	61 / 56–65	60 / 54–64	57 / 51–61	54 / 50–58	54 / 48–58	55 / 47–60	56 / 47–62	59 / 51–64	60 / 54–65	61 / 56–66

Each figure is the median across the 350 grid cells holding the 635 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 2262:4197 (-23.125, 29.875). Over 44 years there: absolute minimum 1.1 °C, 1st-percentile night 5.5 °C, 99th-percentile day 37.8 °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 350 distinct grid cells holding the 635 in-range records; extremes and elevation at the typical cell 2262:4197 (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 -23.00_30.000, lapse-corrected -48 m at 6.5 °C/km. Elevation: ETOPO 2022, 918 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.

NativeMozambique, KwaZulu-Natal, Free State, Northern Provinces· introduced: Western Australia

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

Map marker-29.749, 31.059 · in the densest population, 333 records (52% of those in range)

Evidence usedThe map marker and the climate envelope rest on all 642 georeferenced records inside the native range; the map shows only the 207 openly licensed ones, which alone would put the marker 20 km away. 322 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 642 in-range records; it decides nothing.

Photographs

Photographs: (c) Nicola van Berkel, some rights reserved (CC BY-SA) (7); (c) Dave Richardson, some rights reserved (CC BY).

Photographs: iNaturalist and Wikimedia Commons 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 Barleria obtusa, most cited first, from OpenAlex (CC0). A mention, not a cultivation source: nothing on this page is drawn from them.

Development and expansion of the pollen wall in Barleria obtusa Nees (Acanthaceae)

Alisoun House, K. Balkwill (2019) · South African Journal of Botany

Occurrence Download

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

Occurrence Download

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

Occurrence Download

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

Barleria obtusa Nees