Data sources

Each value Trefle shows for Juglans nigra, with what every source says about it. When sources disagree, the strongest source is shown (how sources are ranked). Values imported before sources were recorded one by one are marked Source not recorded.

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Sourced17 Differs from sources2 Source not recorded10 Not on the record8 Sources: TRY Plant Trait Database, Earlier Trefle data

Field	Shown	What the sources say
Core
Author	L.	No source recorded	Source not recorded
Bibliography	Sp. Pl.: 997 (1753)	No source recorded	Source not recorded
Phylum	Tracheophyta	No source recorded	Source not recorded
Rank	species	No source recorded	Source not recorded
Status	accepted	No source recorded	Source not recorded
Year	1753	No source recorded	Source not recorded
Descriptive
Common name	Black walnut	No source recorded	Source not recorded
Observations	SE. Canada to C. & E. U.S.A.	No source recorded	Source not recorded
Morphology
Average height	1550 cm	1550 cm · TRY Plant Trait Database · Measured · 147 observations · 2026-10-09 TRY 7.0 datasets 20, 25, 28, 68, 92, 184, 500, 673, 818, 873, 918, 925	Sourced
Biological type	phanerophyte	phanerophyte · TRY Plant Trait Database · Measured · 327 observations · 2026-10-09 TRY 7.0 datasets 500, 918, 925	Sourced
Flower color	empty	yellow · TRY Plant Trait Database · Measured · 1 observation · 2026-10-09 TRY 7.0 datasets 92	Not on the record
Flower conspicuous	false	No source recorded	Source not recorded
Foliage color	green	green · TRY Plant Trait Database · Measured · 1 observation · 2026-10-09 TRY 7.0 datasets 92	Sourced
Foliage texture	medium	medium · TRY Plant Trait Database · Measured · 1 observation · 2026-10-09 TRY 7.0 datasets 92	Sourced
Fruit color	brown	brown · TRY Plant Trait Database · Measured · 1 observation · 2026-10-09 TRY 7.0 datasets 92	Sourced
Fruit conspicuous	true	true · Earlier Trefle data · Reported · 2026-10-19 value present before provenance tracking (2022 import), no source recorded	Sourced
Growth form	Single Stem	Single Stem · Earlier Trefle data · Reported · 2026-10-19 value present before provenance tracking (2022 import), no source recorded	Sourced
Growth habit	Tree	Tree · Earlier Trefle data · Reported · 2026-10-19 value present before provenance tracking (2022 import), no source recorded	Sourced
Growth rate	Rapid	Rapid · TRY Plant Trait Database · Measured · 1 observation · 2026-10-09 TRY 7.0 datasets 92	Sourced
Maximum height	3400 cm	3400 cm · TRY Plant Trait Database · Measured · 6 observations · 2026-10-09 TRY 7.0 datasets 20, 25, 28, 68, 92, 184, 500, 673, 818, 873, 918, 925	Sourced
Vegetable	false	No source recorded	Source not recorded
Phenology
Duration	perennial	perennial · TRY Plant Trait Database · Measured · 341 observations · 2026-10-09 TRY 7.0 datasets 25, 28, 92, 424, 759, 818, 918, 925	Sourced
Ecology
Atmospheric humidity	4 / 9 · moderately dry air	4 / 9 · moderately dry air · Earlier Trefle data · Reported · 2026-10-19 value present before provenance tracking (2022 import), no source recorded	Sourced
Ground humidity	empty	6 / 12 · moist (meso-hygrophilous) · TRY Plant Trait Database · Measured · 1 observation · 2026-10-09 TRY 7.0 datasets 489	Not on the record
Light	7 / 9 · half-light to light	5 / 9 · half-shade · TRY Plant Trait Database · Measured · 1 observation · 2026-10-09 TRY 7.0 datasets 489	Differs from sources
Nitrogen fixation	None	None · TRY Plant Trait Database · Measured · 14 observations · 2026-10-09 TRY 7.0 datasets 20, 57, 67, 71, 89, 444, 445, 822	Sourced
Ph maximum	pH 8.2	pH 8.2 · Earlier Trefle data · Reported · 2026-10-19 value present before provenance tracking (2022 import), no source recorded	Sourced
Ph minimum	pH 4.6	pH 4.6 · Earlier Trefle data · Reported · 2026-10-19 value present before provenance tracking (2022 import), no source recorded	Sourced
Soil nutriments	6 / 9 · rather rich (meso-eutrophic)	7 / 9 · rich (eutrophic) · TRY Plant Trait Database · Measured · 1 observation · 2026-10-09 TRY 7.0 datasets 489	Differs from sources
Soil salinity	0 / 9 · absent from saline soils	0 / 9 · absent from saline soils · TRY Plant Trait Database · Measured · 1 observation · 2026-10-09 TRY 7.0 datasets 489	Sourced
Cultivation
Minimum root depth	220 cm	220 cm · TRY Plant Trait Database · Measured · 9 observations · 2026-10-09 TRY 7.0 datasets 92, 432, 818	Sourced
Usda legacy
C n ratio	empty	18.3 · TRY Plant Trait Database · Measured · 26 observations · 2026-10-09 TRY 7.0 datasets 79, 424, 981	Not on the record
Other
Human usage type	—	berries_nuts_seeds, fuelwood, lumber, medical, nursery_stock, ornamental, timber, veneer · TRY Plant Trait Database · Reported · 1 observation · 2026-10-09 TRY 7.0 datasets 68, 92	Not on the record
Salt tolerance	—	None · TRY Plant Trait Database · Measured · 1 observation · 2026-10-09 TRY 7.0 datasets 92	Not on the record
Shade tolerance	—	None · TRY Plant Trait Database · Measured · 1 observation · 2026-10-09 TRY 7.0 datasets 92	Not on the record
Soil ph indicator	—	6 · TRY Plant Trait Database · Measured · 1 observation · 2026-10-09 TRY 7.0 datasets 489	Not on the record
Temperature indicator	—	6 · TRY Plant Trait Database · Measured · 1 observation · 2026-10-09 TRY 7.0 datasets 489	Not on the record

Juglans nigra L., 1753 50% complete

Black walnut

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Data sources