Malacothamnus marrubioides (Durand & Hilg.) Greene
Horehound bush-mallow; Pink-flowered bushmallow
152 photographs › At a glance
- Jan, shaded
- Feb, shaded
- Mar, shaded
- Apr
- May
- Jun, under 5 mm of rain
- Jul, under 5 mm of rain
- Aug, under 5 mm of rain
- Sep
- Oct
- Nov
- Dec, shaded
Summary
Malacothamnus marrubioides is a species of flowering plant in the mallow family known by the common name Santa Clarita bushmallow. It is currently only known from Los Angeles and Ventura counties in California, though its purported type locality suggests it may have occurred further north under or near what is now Millerton Lake.
Quoted from Wikipedia, "Malacothamnus marrubioides", CC BY-SA 4.0.
Cultivation
Seasons
The rain rule reads a winter growing season: 70% of the median year's rain (294 mm of 400 mm) falls in December to March, cooler than the year (wet-season mean 9.9 °C against a yearly mean of 16.0 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: June to September.
Rain
400 mm in the median year at the habitat, 294 mm of it December to March. Wettest month February at 94 mm, driest months (3 at 2 mm); 3 months under 5 mm. Across the grid cells of the range the year's total runs 374 mm to 436 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 405 mm, is the year's rain at the top of the page; the 400 mm here is the median year's, the twelve monthly medians added, which the rain rule reads. Habitat calendar, northern hemisphere; median year across the grid cells of the range, CHELSA.
Light
Open sky over the habitat: 19 to 54 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 16, the highest 90th-percentile month 55).
Warmth and air
Coldest: the 1st-percentile night over 44 years at a typical spot in the range is -2.4 °C, the absolute minimum -6.9 °C, 799 frost nights in 44 years, 18.2 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 41.2 °C. Monthly means: the coldest month's mean nightly low 3.7 °C in December (across the grid cells of the range 2.4 °C to 4.8 °C), the warmest month's mean daily high 32.2 °C in August (median year across the grid cells of the range, CHELSA). Cold floor: -2.4 °C, which is the 1st-percentile night over 44 years at a typical spot in the range (NASA POWER).
Relative humidity at the habitat: 49 to 55% 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 -27 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.
Climate across the habitat
Habitat months, northern hemisphere
Mean daily high from 15 °C in Jan and Dec to 32 °C in Jul and Aug; mean nightly low from 4 °C in Jan and Dec to 18 °C in Aug. The cold quarter, Nov to Jan, is the three months around the coldest month's mean nightly low, centred on the 2 months in a row that tie for it. 400 mm of rain in the median year (the twelve monthly medians added), the wettest month Feb. The bands show the 10th to 90th percentile across 43 habitat cells. Over 44 years at a typical spot in the range (NASA POWER) the absolute minimum was -6.9 °C and the 99th-percentile day 41.2 °C; neither is dated to a month. Beneath: daily light integral and relative humidity through the year, each on its own scale.
Figures by month
| Figure | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Day °C | 15 / 13–17 | 16 / 14–18 | 19 / 17–20 | 22 / 21–23 | 26 / 24–26 | 29 / 28–30 | 32 / 31–33 | 32 / 31–33 | 30 / 29–31 | 25 / 24–26 | 19 / 18–21 | 15 / 13–17 |
| Night °C | 4 / 3–5 | 5 / 3–6 | 6 / 4–7 | 8 / 6–9 | 11 / 10–12 | 14 / 13–15 | 17 / 17–18 | 18 / 17–18 | 16 / 15–17 | 11 / 10–13 | 7 / 6–8 | 4 / 2–5 |
| Rain mm | 80 / 75–89 | 94 / 86–103 | 61 / 56–67 | 27 / 25–30 | 8 / 7–9 | 2 / 2–3 | 2 / 1–2 | 2 / 2–3 | 6 / 5–7 | 20 / 18–22 | 39 / 35–43 | 59 / 55–65 |
| DLI | 20 / 18–21 | 26 / 24–26 | 36 / 34–36 | 45 / 43–45 | 51 / 50–51 | 54 / 53–55 | 52 / 52–53 | 48 / 47–49 | 40 / 39–41 | 31 / 29–32 | 23 / 21–24 | 19 / 16–19 |
| RH % | 54 / 51–55 | 55 / 53–56 | 55 / 54–56 | 53 / 51–54 | 52 / 49–55 | 51 / 47–53 | 50 / 46–52 | 49 / 46–51 | 50 / 47–52 | 50 / 48–52 | 51 / 48–52 | 52 / 50–53 |
How this section is made
Natural habitat
How this section is made
Photographs
Photographs: (c) Adam J. Searcy, some rights reserved (CC BY) (6).
Related
Similar habitat climate The 6 nearest by mean daily high, mean nightly low and rain, month by month. How.
Lepidospartum squamatum California broomsage Photo: CC BY, Richard Bachen
Malacothamnus davidsonii Davidson's bushmallow Photo: CC0, author not stated
Emmenanthe penduliflora Whispering-bells Photo: CC BY, Matt Berger
Nicotiana quadrivalvis Indian tobacco Photo: CC BY-SA, Brian Finzel
Allium crispum Crinkled onion Photo: CC BY-SA, paulexcoffOther Malacothamnus 19 in the reference
Malacothamnus abbottii Abbot's bushmallow Photo: CC BY, Trevor Van Loon
Malacothamnus aboriginum Indian Valley bush-mallow Photo: CC BY, Trevor Harding Malacothamnus arcuatus Malvaceae Malacothamnus astrotentaculatus Malvaceae 
Malacothamnus clementinus San Clemente Island bush-mallow Photo: CC BY, Melanie J. Davis Malacothamnus davidsonii Davidson's bushmallow Photo: CC0, author not stated
Malacothamnus densiflorus Yellow-stem bush-mallow Photo: CC BY, Ian McFaul Malacothamnus discombobulatus Malvaceae Malacothamnus eastwoodiae Malvaceae 
Malacothamnus enigmaticus Enigmatic bush-mallow Photo: CC0, author not stated
Malacothamnus fasciculatus Mendocino bush-mallow Photo: CC BY, Sarah Dillion
Malacothamnus fremontii Fremon's bushmallow Photo: CC0, author not stated all 20 ›Names & registers
Also known as Malvastrum gabrielense; Malvastrum marrubioides; Malveopsis marrubiodes; Malveopsis marrubioides; Sphaeralcea densiflora var. gabrielensis and 1 more. (GBIF Backbone)
The record
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 answeredasked 2026-10-22gbif.synonyms answeredasked 2026-10-22gbif.vernacular answeredasked 2026-10-22names fetched 2026-10-22wcvp.distribution answeredas of 2026-06-04gbif.occurrences answeredas of 2026-10-21GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21; 2 records within 1 km of a botanic garden, herbarium or zoo left out (1 at a botanic garden or arboretum, 1 at a zoo; Wikidata's list)climate answeredasked 2026-10-22climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell 34.50_-118.125, lapse-corrected -27 m at 6.5 °C/kmwikidata answeredasked 2026-10-22wikipedia answeredasked 2026-10-22inat.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 2026-10-22inat.photos.cultivated not askedgbif.media answeredasked 2026-10-22openalex not askednot yet asked for this reference; a later fill takes the papers from OpenAlex's snapshotEvery 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 13 datasets via GBIF.org; each carries its own licence.