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Xylosma congesta; photograph Agnes Trekker, CC0, via Wikimedia Commons CC0Agnes Trekker, CC0, via Wikimedia Commons

Xylosma congesta (Lour.) Merr.

Salicaceae · China South-Central, China North-Central +6

English names not checked: Wikidata's common names were not read for this page.

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Xylosma congesta, photograph Agnes Trekker, CC0, via Wikimedia CommonsXylosma congesta, photograph Agnes Trekker, CC0, via Wikimedia CommonsXylosma congesta, photograph Agnes Trekker, CC0, via Wikimedia CommonsXylosma congesta, photograph Agnes Trekker, CC0, via Wikimedia CommonsXylosma congesta, photograph Agnes Trekker, CC0, via Wikimedia CommonsXylosma congesta, photograph Agnes Trekker, CC0, via Wikimedia Commons 12 photographs ›
Habitat figures
Cold floor (1 night in 100)
1.0°C
Record low -3.7 °C in 44 years, at a typical spot in the range NASA POWER
Warmest month, mean daily high
28°C
Jul and Aug at the habitat CHELSA
Rain a year (median across the range)
2,029mm
12 months of 25 mm or more in the median year CHELSA
Open-sky light
16–35DLI
Lowest to highest month (DLI) CHELSA
The year in your months, northern hemisphere
  1. Jan
  2. Feb
  3. Mar
  4. Apr
  5. May
  6. Jun
  7. Jul
  8. Aug
  9. Sep
  10. Oct
  11. Nov
  12. Dec
Wet summers: the rain comes April to September, read as a summer growing season. rain rule, CHELSA
Northern hemisphere unless you set your site. The chart is in the habitat's months.

Summary

Xylosma congesta, commonly known as shiny xylosma, is a species of flowering plant in the family Salicaceae, native to East Asia. Originally described in 1790 as Croton congestus, the species was later reassigned to Xylosma in 1919. The plant is widely grown ornamentally for its dense growth habit and shiny foliage, but its introduction to the United States as a result has led to its emergence as a potential invasive species. Other common names include dense logwood and zuo mu (Chinese: 柞木).

Quoted from Wikipedia, "Xylosma congesta", CC BY-SA 4.0.

Cultivation

Seasons

The rain rule reads a summer growing season: 70% of the median year's rain (1,435 mm of 2,000 mm) falls in April to September, warmer than the year (wet-season mean 22.6 °C against a yearly mean of 17.1 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: October to March.

Rain

2,000 mm in the median year at the habitat, 1,435 mm of it April to September. Wettest month July at 299 mm, driest month December at 58 mm. Across the grid cells of the range the year's total runs 1,385 mm to 3,194 mm, the 10th to 90th percentile of each cell's own year. The median of the cells' own yearly totals, 2,029 mm, is the year's rain at the top of the page; the 2,000 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: 16 to 35 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 14, the highest 90th-percentile month 38).

Warmth and air
Temperature

Coldest: the 1st-percentile night over 44 years at a typical spot in the range is 1.0 °C, the absolute minimum -3.7 °C, 54 frost nights in 44 years, 1.2 a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 32.7 °C. Monthly means: the coldest month's mean nightly low 4.5 °C in January (across the grid cells of the range 0.6 °C to 9.7 °C), the warmest month's mean daily high 28.3 °C in August (median year across the grid cells of the range, CHELSA). Cold floor: 1.0 °C, which is the 1st-percentile night over 44 years at a typical spot in the range (NASA POWER).

Humidity

Relative humidity at the habitat: 57 to 68% 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 -81 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

Habitat climate of Xylosma congesta through the yearWarmest months July and August, mean daily high 28 °C; coldest month January, mean nightly low 4.5 °C; 2,000 mm of rain in the median year (the twelve monthly medians added). Medians across the range, from CHELSA; the extremes at the edge from NASA POWER. Habitat months, northern hemisphere.-10°0°10°20°30°40°frost32.7° 99th-percentile day, NASA POWER-3.7° lowest night in 44 years, NASA POWER°C · day and nightcold quarter0100200300400500mm rainDLI 16–35RH 57–68%JanFebMarAprMayJunJulAugSepOctNovDec
day night rain medians and 10th–90th percentile across 89 habitat cells, CHELSA cold quarter: the three months around the coldest month's mean nightly low extremes over 44 years at a typical spot in the range, from NASA POWER, marked at the edge, in no month DLI, mol/m²/dayRH %each on its own scale
Figures by month
JanFebMarAprMayJunJulAugSepOctNovDec
Day °C9 / 7–1510 / 8–1514 / 11–1818 / 15–2222 / 19–2625 / 22–2828 / 26–3228 / 26–3126 / 24–2822 / 19–2417 / 14–2012 / 10–16
Night °C5 / 1–105 / 2–108 / 5–1212 / 10–1616 / 14–1920 / 18–2324 / 20–2625 / 20–2622 / 18–2417 / 14–2012 / 8–167 / 3–12
Rain mm74 / 41–11292 / 61–167151 / 96–210157 / 107–238199 / 128–328287 / 197–484299 / 152–432268 / 159–433225 / 140–47699 / 70–26591 / 61–17258 / 38–112
DLI16 / 14–1920 / 18–2326 / 21–2932 / 26–3534 / 29–3632 / 28–3435 / 32–3833 / 31–3628 / 27–2924 / 22–2518 / 17–2016 / 14–18
RH %58 / 55–6458 / 55–6559 / 57–6561 / 59–6763 / 61–6967 / 64–7168 / 64–7367 / 64–7064 / 61–6860 / 58–6658 / 56–6557 / 55–63
How this section is made
Each figure is the median across the 89 grid cells on land that hold in-range records (107 records in those cells; 1 more cell holds records but no land by the elevation layer, so those records sit at sea and the cell is left out), with the 10th–90th percentile span across those cells after the slash where it differs. A dash is a month one or more of those cells has no figure for in the grid (a variable CHELSA does not carry there), so no median is taken rather than one over fewer cells. Extremes and elevation were read at a typical spot in the range, cell 1139:6238 (33.025, 131.925). Over 44 years there: absolute minimum -3.7 °C, 1st-percentile night 1.0 °C, 99th-percentile day 32.7 °C. Normals: CHELSA V2.1 1981–2010 climatology, 0.05° cells (each the mean of ~36 1 km pixels). Across the range: median and 10th–90th percentile of each month across the 89 distinct grid cells holding 107 of the 108 in-range records (1 further cell with records at sea, by the elevation layer, left out); extremes and elevation at the typical cell 1139:6238 (its coldest month's mean nightly low nearest the median across cells); its position is the cell centre. Extremes: NASA POWER (MERRA-2) daily 1981–2024, cell 33.00_131.875, lapse-corrected -81 m at 6.5 °C/km. Elevation: ETOPO 2022, 54 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 the cells of the in-range records placed well enough to read one, not at the marker.
Openly licensed records inside the range, framed on where they fall.

This species has no GBIF key of its own. Its records are GBIF's under the keys of the names Kew's World Checklist holds as this plant: 3059908 (Croton congestus Lour., 1 record), 3059909 (Kurkas congestum (Lour.) Raf., 0 records), 7110846 (Xylosma congesta (Lour.) Merr., 439 records). No name was matched to GBIF; the keys are read from Kew's synonymy. How.

NativeChina South-Central, China North-Central, China Southeast, Tibet, Japan, Korea, Nansei-shoto, Taiwan · introduced: Florida · regions are the level-3 units of the World Geographical Scheme for Recording Plant Distributions, as Kew's World Checklist records ranges, some under historical names such as Yugoslavia or Czechoslovakia (how).
Map marker31.83, 130.32 · in the densest population, 129 records (55% of those in range)
Kew's description“shrub or tree” · “temperate” · quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Evidence usedThe map marker rests on all 234 georeferenced records inside the native range; the climate across the range on the 107 of them in the land cells it reads, of 108 placed to within 10 km; the map shows only the 120 openly licensed ones, which alone would put the marker 34 km away. 64 records outside the WCVP native range not used. 126 in-range records are placed to worse than 10 km, or with no stated accuracy (admitted only as a person's observation to three decimals), and stay on the map but off the climate.
Other GBIF keysRecords also from GBIF's key 3059908 (Croton congestus Lour.): Kew's file holds it as Croton congestus Lour. (synonym under Xylosma congesta (Lour.) Merr.); 1 record, from GBIF's download.Records also from GBIF's key 3059909 (Kurkas congestum (Lour.) Raf.): Kew's file holds it as Kurkas congestum (Lour.) Raf. (synonym under Xylosma congesta (Lour.) Merr.); 0 records, from GBIF's search API on the day of the build.Records also from GBIF's key 7110846 (Xylosma congesta (Lour.) Merr.): Kew's file holds it as Xylosma congesta (Lour.) Merr. (accepted); 439 records, from GBIF's download.
How this section is made
The map marker: the openly licensed record nearest the middle of the densest 1° population inside the densest 4° block of the 234 in-range records; it decides nothing. Records outside the native range, living specimens and records marked introduced are not used; which records count.

Photographs

Xylosma congesta, photograph 1did not loadXylosma congesta, photograph 2did not loadXylosma congesta, photograph 3did not loadXylosma congesta, photograph 4did not loadXylosma congesta, photograph 5did not loadXylosma congesta, photograph 6did not load

Photographs: Agnes Trekker, CC0, via Wikimedia Commons (6).

Similar habitat climate The 6 nearest by mean daily high, mean nightly low and rain, month by month. How.

Podocarpus macrophyllus Podocarpus macrophyllus Buddhist pine Photo: CC BY, Jenny SaitoFarfugium japonicum Farfugium japonicum Leopard plant Photo: CC BY, WATANABE Hitoshi 渡辺仁Distylium racemosum Distylium racemosum Evergreen witch hazel Photo: CC0, Mason BrockMachilus thunbergii Machilus thunbergii Thunberg’s bay-tree Photo: CC BY, 胡正恆(Jackson Hu)Elaeagnus pungens Elaeagnus pungens Spiny oleaster Photo: CC0, author not statedElaeagnus × reflexa Elaeagnus × reflexa Elaeagnaceae Photo: CC0, author not stated

Other Xylosma 6 in the reference

Xylosma flexuosa Xylosma flexuosa Brushholly Photo: CC BY, Carlos Domínguez-Rodríguez Xylosma hawaiensis Salicaceae Xylosma ovata Xylosma ovata Salicaceae Photo: CC BY-SA, Greg TasneyXylosma spiculifera Xylosma spiculifera Salicaceae Photo: CC BY, Eric SchmidtXylosma tweediana Xylosma tweediana Salicaceae Photo: CC BY, Gastón RepettoXylosma venosa Xylosma venosa Salicaceae Photo: CC0, author not stated

Names & registers

Also known as Myroxylon japonicum; Apactis japonica; Xylosma racemosa var. glaucescens; Xylosma racemosa var. pubescens; Xylosma congesta var. pubescens and 16 more. (WCVP, RBG Kew)

IPNIPOWOWikidataWFOWikipedia

The record

Family
Salicaceae
Described by
(Lour.) Merr.
Native to
China South-Central, China North-Central, China Southeast +5
Wild records
234 in range · 120 open

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
Kew's names (WCVP) kew.names answeredas of 2026-06-04Kew's entry Xylosma congesta (Lour.) Merr. (plant_name_id 2923415), read from Kew's names file
GBIF species record gbif.species not askedGBIF's backbone holds no one accepted species of this name, and a name it holds only as another species' synonym is not taken for this one, so GBIF's records were not asked
GBIF synonyms gbif.synonyms not askedGBIF's backbone holds no one accepted species of this name, and a name it holds only as another species' synonym is not taken for this one, so GBIF's records were not asked
GBIF common names gbif.vernacular not askedGBIF's backbone holds no one accepted species of this name, and a name it holds only as another species' synonym is not taken for this one, so GBIF's records were not asked
WCVP native range wcvp.distribution answeredas of 2026-06-04
GBIF occurrence records gbif.occurrences answeredasked 2026-10-22this species has no GBIF key of its own; its records are read under GBIF's keys for the names Kew's file holds as this plant, never by a name matched; GBIF occurrence download https://doi.org/10.15468/dl.hbdw64, of 2026-10-21; 1 record of GBIF's key 3059908, Croton congestus Lour. (Kew's file holds it as Croton congestus Lour. (synonym under Xylosma congesta (Lour.) Merr.)): the GBIF download; 0 records of GBIF's key 3059909, Kurkas congestum (Lour.) Raf. (Kew's file holds it as Kurkas congestum (Lour.) Raf. (synonym under Xylosma congesta (Lour.) Merr.)): GBIF occurrence search API; 439 records of GBIF's key 7110846, Xylosma congesta (Lour.) Merr. (Kew's file holds it as Xylosma congesta (Lour.) Merr. (accepted)): the GBIF download; 35 records within 1 km of a botanic garden, herbarium or zoo left out (18 at a botanic garden or arboretum, 9 at a herbarium, 8 at a zoo; Wikidata's list)
Habitat climate climate answeredasked 2026-10-22
Daily extremes (NASA POWER) climate.extremes answeredasked 2026-10-22NASA POWER (MERRA-2) daily 1981–2024, cell 33.00_131.875, lapse-corrected -81 m at 6.5 °C/km
Wikidata wikidata answeredasked 2026-10-22found by Kew's IPNI identifier 366060-1, POWO 366060-1
Wikipedia wikipedia answeredasked 2026-10-22
iNaturalist photographs, wild inat.photos.wild not asked
iNaturalist photographs, cultivated inat.photos.cultivated not asked
GBIF media gbif.media not askedGBIF's backbone holds no one accepted species of this name, and a name it holds only as another species' synonym is not taken for this one, so GBIF's records were not asked
Wikimedia Commons commons answeredasked 2026-10-22
OpenAlex papers openalex not askednot yet asked for this reference; a later fill takes the papers from OpenAlex's snapshot

Every 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 47 datasets via GBIF.org; each carries its own licence.

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