Myrospermum sousanum A.Delgado & M.C.Johnst.
Arroyo Sweetwood
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
Myrospermum sousanum, the arroyo sweetwood, is a species of flowering plant in the family Fabaceae. It is native to northeastern Mexico. A shrub or small tree, it is typically found in shrublands and inland wetlands at elevations from 460 to 1,300 m. Known from only four stations, it has been assessed as Endangered.
Text from Wikipedia, “Myrospermum sousanum”, CC BY-SA 4.0, quoted as written. Kept separate from everything derived here.
About the genus · Myrospermum
Myrospermum is a genus of flowering plants in the legume family, Fabaceae. It includes two species of trees and shrubs native to the tropical Americas, ranging from northeastern Mexico through Central America to Colombia and Venezuela. Typical habitats include seasonally-dry tropical to subtropical woodland and bushland, often on rocky hillsides and along rivers and streams.Myrospermum frutescens Jacq. – central Mexico to Colombia and Venezuela Myrospermum sousanum A.Delgado & M.C.Johnst. – northeastern Mexico
Text from Wikipedia, “Myrospermum”, CC BY-SA 4.0, quoted as written.
At a glance
Cultivation
Its year Rain rule: a summer growing season, May to October in the northern hemisphere (May to October at the habitat, northern).
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 (443 mm of 605 mm) falls in May to October, warmer than the year (wet-season mean 25.8 °C against a yearly mean of 21.0 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: November to April.
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 605 mm a year, wettest September at 129 mm, driest December at 19 mm (habitat calendar, northern hemisphere).
This species’ habitat figures, with their source.
605 mm a year at the habitat, 443 mm of it May to October. Wettest month September at 129 mm, driest December at 19 mm. Across the envelope cells the year's total runs 550 mm to 772 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: 20 to 43 mol/m²/day.
This species’ habitat figures, with their source.
Open sky over the habitat: 20 to 43 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 18, 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 -0.4 °C (1st-percentile habitat night, NASA POWER).
This species’ habitat figures, with their source.
Coldest: the 1st-percentile night over 44 years at the typical cell is -0.4 °C, the absolute minimum -8.7 °C, about 4 frost nights a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 40.8 °C. Monthly means: coldest night 7.3 °C in January (across the envelope cells 6.5 °C to 7.8 °C), warmest day 33.5 °C in July (median year across the envelope cells, CHELSA). Cold floor: -0.4 °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.
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
Figures by month
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Day °C | 20 / 18–21 | 22 / 20–23 | 26 / 23–27 | 30 / 27–31 | 31 / 30–33 | 33 / 32–33 | 34 / 32–34 | 33 / 32–35 | 30 / 29–31 | 27 / 26–27 | 23 / 22–24 | 20 / 18–21 |
| Night °C | 7 / 7–8 | 9 / 8–10 | 12 / 11–13 | 16 / 15–16 | 20 / 19–20 | 22 / 21–23 | 22 / 21–23 | 22 / 21–24 | 20 / 19–21 | 16 / 15–17 | 12 / 11–12 | 8 / 7–9 |
| Rain mm | 33 / 29–47 | 23 / 20–45 | 25 / 22–52 | 42 / 34–58 | 63 / 52–85 | 59 / 55–92 | 63 / 56–65 | 75 / 53–81 | 129 / 86–138 | 54 / 45–87 | 20 / 17–54 | 19 / 16–48 |
| DLI | 21 / 20–21 | 26 / 24–27 | 34 / 30–34 | 38 / 36–39 | 41 / 38–41 | 43 / 41–43 | 43 / 43–43 | 41 / 40–41 | 33 / 32–33 | 28 / 27–28 | 23 / 21–23 | 20 / 18–20 |
| RH % | 56 / 56–57 | 55 / 54–57 | 54 / 52–56 | 55 / 53–56 | 59 / 57–60 | 59 / 57–60 | 57 / 56–58 | 56 / 55–57 | 61 / 57–62 | 59 / 57–60 | 57 / 56–58 | 56 / 55–57 |
Each figure is the median across the 4 grid cells holding the 4 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 1269:1589 (26.525, -100.525). Over 44 years there: absolute minimum -8.7 °C, 1st-percentile night -0.4 °C, 99th-percentile day 40.8 °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 4 distinct grid cells holding the 4 in-range records; extremes and elevation at the typical cell 1269:1589 (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 26.50_-100.625, lapse-corrected +23 m at 6.5 °C/km. Elevation: ETOPO 2022, 693 m (cell mean).
Natural habitat
Papers naming this species
Works whose title or abstract names Myrospermum sousanum, most cited first, from OpenAlex (CC0). A mention, not a cultivation source: nothing on this page is drawn from them.
Related
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.
Hesperaloe funifera New Mexico False Yucca
Coryphantha nickelsiae Nickels' Cactus
Bauhinia lunarioides Anacacho orchid Yucca coahuilensis Coahuila soapwort
Echinocereus enneacanthus PitayaHistory & 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 answeredgbif.occurrences answeredGBIF occurrence download https://doi.org/10.15468/dl.3h4zamclimate answeredwikidata 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: skippedinat.taxon not askedinat.photos.wild nothing to reportcarried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)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 did not answerapi.gbif.org not asked: offline re-derivationopenalex answeredcarried from build of 2026-09-19; this build: skippedEvery upstream is recorded as having answered, reported nothing, or refused. Only “nothing to report” is ever shown as an absence. Records came from 8 datasets via GBIF.org; each carries its own licence.