Species
+

Buxus microphylla Siebold & Zucc.

Box tree, Common box tree, Japanese Box, Littleleaf box, Japanese box, Littleleaf boxwood

Climate known 15 photographs Temperate garden plant
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

Buxus microphylla, the Japanese box or littleleaf box, is a species of flowering plant in the box family found in Japan and Taiwan. It is a dwarf evergreen shrub or small tree growing to 1 m (3.3 ft) tall and wide.

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

About the genus · Buxus

Buxus is a genus of about seventy species in the family Buxaceae. Common names include box and boxwood.

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

Family
Buxaceae
Described by
Siebold & Zucc.
Native to
Japan
Wild records
245 in range· 206 open

At a glance

Warmest month
28°C
Aug, mean day; nights 22 °C (CHELSA)
Rain
2118mm/yr
12 wet months · peak Jul 278 mm (CHELSA)
Light
15–35DLI
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 temperate garden plant by the genus Buxus, which is reliably one kind of plant (archetype table). Rain rule: a summer growing season, March and May to October in the northern hemisphere (March and May to October at the habitat, northern). Habitat rain 2118 mm a year, wettest July at 278 mm, driest December at 78 mm (habitat calendar, northern hemisphere). Open sky over the habitat: 15 to 35 mol/m²/day. Cold floor -4.6 °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 Buxus fortunei Carrière; Buxus japonica Mull.Arg. ex Miq.; Buxus japonica Müll.Arg.; Buxus japonica var. microphylla (Siebold & Zucc.) Müll.Arg.; Buxus japonica var. microphylla (Siebold & Zucc.) Müll.Arg. ex Miq. and 17 more.

Cultivation

Grouped as a temperate garden plant by the genus Buxus, 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, March and May to October in the northern hemisphere (March and 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 (1549 mm of 2118 mm) falls in March and May to October, warmer than the year (wet-season mean 19.0 °C against a yearly mean of 14.0 °C). Months are the habitat's, northern hemisphere; shifted six months for a southern-hemisphere collection: November to April and 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 2118 mm a year, wettest July at 278 mm, driest December at 78 mm (habitat calendar, northern hemisphere).

This species’ habitat figures, with their source.

2118 mm a year at the habitat, 1549 mm of it March and May to October. Wettest month July at 278 mm, driest December at 78 mm. Across the envelope cells the year's total runs 1438 mm to 3541 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: 15 to 35 mol/m²/day.

This species’ habitat figures, with their source.

Open sky over the habitat: 15 to 35 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 12, the highest 90th-percentile month 36).

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 -4.6 °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 -4.6 °C, the absolute minimum -10.1 °C, about 70 frost nights a year (NASA POWER daily minima). Warmest: the 99th-percentile day is 35.9 °C. Monthly means: coldest night -1.5 °C in January (across the envelope cells -7.2 °C to 5.3 °C), warmest day 27.6 °C in August (median year across the envelope cells, CHELSA). Cold floor: -4.6 °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 67% 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 6 °C in Jan to 28 °C in Aug; mean night from -2 °C in Jan to 22 °C in Aug. The cold quarter, Dec to Feb, is the three months around the coldest night. 2118 mm of rain a year, most in Jul. The bands show the 10th to 90th percentile across 188 habitat cells. Over 44 years at the typical cell the absolute minimum was -10.1 °C and the 99th-percentile day 35.9 °C; neither is dated to a month. Beneath: daily light integral and relative humidity through the year, each on its own scale.-20°-10°10°20°30°40°frost35.9° 99th-percentile day (undated)-10.1° lowest night in 44 yrs (undated)°C · day and nightcold quarter0100200300400500mm rainDLI 15–35RH 59–67 %JanFebMarAprMayJunJulAugSepOctNovDec
day night rain 10th–90th percentile across 188 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 °C6 / 0–107 / 1–1010 / 5–1316 / 11–1820 / 16–2223 / 19–2526 / 23–2828 / 24–3024 / 21–2619 / 15–2114 / 9–178 / 3–12
Night °C-2 / -7–5-1 / -7–52 / -3–87 / 2–1212 / 8–1617 / 13–2021 / 17–2422 / 18–2518 / 14–2212 / 8–176 / 1–131 / -5–8
Rain mm91 / 48–304113 / 55–224166 / 102–274157 / 117–275189 / 134–325245 / 167–450278 / 176–434216 / 139–370262 / 189–431193 / 107–351130 / 73–29878 / 47–303
DLI17 / 14–1921 / 19–2427 / 25–2933 / 31–3435 / 32–3632 / 28–3532 / 29–3533 / 30–3626 / 23–2822 / 19–2417 / 14–1915 / 12–17
RH %59 / 54–6559 / 54–6459 / 56–6259 / 57–6161 / 59–6465 / 62–6967 / 64–7166 / 63–6965 / 62–6861 / 59–6560 / 57–6360 / 55–64

Each figure is the median across the 188 grid cells holding the 241 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 1084:6391 (35.775, 139.575). Over 44 years there: absolute minimum -10.1 °C, 1st-percentile night -4.6 °C, 99th-percentile day 35.9 °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 188 distinct grid cells holding the 241 in-range records; extremes and elevation at the typical cell 1084:6391 (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 36.00_139.375, lapse-corrected -224 m at 6.5 °C/km. Elevation: ETOPO 2022, 40 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.
NativeJapan
Kew's description“shrub” · “temperate”· quoted from WCVP, RBG Kew (CC BY 4.0); not derived here
Map marker35.8, 139.1 · in the densest population, 157 records (64% of those in range)
Evidence usedThe map marker and the climate envelope rest on all 245 georeferenced records inside the native range; the map shows only the 206 openly licensed ones, which alone would put the marker 1 km away. 241 records outside the range (gardens, roadsides, misidentifications) ignored. 4 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 2° block of the 245 in-range records; it decides nothing.

Photographs

Buxus microphyllaBuxus microphyllaBuxus microphyllaBuxus microphyllaBuxus microphyllaBuxus microphyllaBuxus microphyllaBuxus microphylla

Photographs: (c) Marco Mussita, some rights reserved (CC BY) (4); unknown, CC BY, via GBIF (4).

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

Cyclovirobuxine D Attenuates Doxorubicin-Induced Cardiomyopathy by Suppression of Oxidative Damage and Mitochondrial Biogenesis Impairment
Qian Guo, Jiabin Guo, Rong Yang, Hui Peng (2015) · Oxidative Medicine and Cellular Longevity
Cyclovirobuxine D Induced-Mitophagy through the p65/BNIP3/LC3 Axis Potentiates Its Apoptosis-Inducing Effects in Lung Cancer Cells
Cheng Zeng, Tingting Zou, Junyan Qu, Chen Xu (2021) · International Journal of Molecular Sciences
Cyclovirobuxine inhibits the progression of clear cell renal cell carcinoma by suppressing the IGFBP3-AKT/STAT3/MAPK-Snail signalling pathway
Yadong Liu, Huiyan Lv, Xingyi Li, Jiannan Liu (2021) · International Journal of Biological Sciences
Water Use and Crop Coefficients of Woody Ornamentals in Containers
Ursula K. Schuch, David W. Burger (1997) · Journal of the American Society for Horticultural Science
Distribution of Guaiacyl and Syringyl Lignins in Normal and Compression Wood of Buxus Microphylla Var. Insularis Nakai
Nobuo Yoshizawa, Naomi Watanabe, Sbinso Yokota, Tosbinaga Idei (1993) · IAWA Journal - KU Leuven/IAWA Journal
Cyclovirobuxine D inhibits colorectal cancer tumorigenesis via the CTHRC1‑AKT/ERK‑Snail signaling pathway
Fengqi Jiang, Yaodong Chen, Shuo Ren, Zizhuo Li (2020) · International Journal of Oncology
Cytotoxic Triterpenoid Alkaloids from Buxus microphylla
Yu‐Xin Yan, Xiao-Dong Hu, Jianchao Chen, Yun Sun (2009) · Journal of Natural Products
Growth Response, Mineral Nutrition, and Water Utilization of Container-grown Woody Ornamentals Grown in Biochar-amended Pine Bark
Nastaran Basiri Jahromi, Forbes Walker, Amy Fulcher, James E. Altland (2018) · HortScience

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 Buxus 1 in the reference

History & registers

Where this page came from built 2026-09-20 · dossier v2 · node
gbif.species answeredcarried from build of 2026-09-20 (offline re-derivation; the backbone was not asked)
gbif.synonyms answeredcarried from build of 2026-09-20 (offline re-derivation; the backbone was not asked)
gbif.vernacular answeredcarried from build of 2026-09-20 (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 2026-09-20 (rederive); that build: carried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
wikipedia answeredcarried from build of 2026-09-20; this build: skipped
inat.taxon not askedcarried from build of 2026-09-20 (rederive)
inat.photos.wild answeredcarried from build of 2026-09-20; this build: skipped
inat.photos.cultivated nothing to reportcarried from build of 2026-09-20 (rederive); that build: carried from build of 2026-09-19 (rederive); that build: carried from build of 2026-09-19 (rederive)
commons nothing to reportcarried from build of 2026-09-20 (rederive); that build: carried 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 2026-09-20; 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 98 datasets via GBIF.org; each carries its own licence.