{ "$schema": "https://botanai.app/schema/species-v1.json", "schema_version": 1, "url": "https://botanai.app/plants/centaurea-nigrescens/", "last_modified": "2025-12-15", "id": { "slug": "centaurea-nigrescens", "wfo": "wfo-0000085587", "inat_taxon_id": 160277 }, "name": { "scientific": "Centaurea nigrescens", "authorship": "Willd.", "genus": "Centaurea", "epithet": "nigrescens", "family": "Asteraceae", "rank": "species", "taxonomic_status": "accepted", "accepted_according_to": "World Flora Online Plant List, 2026-06", "is_homonym": false, "published_in": "Sp. Pl., ed. 4, 3: 2288 (1803)", "protologue_url": "https://www.compositae.org/gcd/aphia.php?p=taxdetails&id=1083408", "common": { "preferred": "Black knapweed", "english": [ "Black knapweed", "Tyrol knapweed", "Tyrol thistle", "short-fringed knapweed" ], "source": "wikidata" }, "synonyms": [ { "name": "Centaurea bracteata", "authorship": "Balb. ex Steud." }, { "name": "Centaurea brevipappa", "authorship": "Boiss. & Reut." }, { "name": "Centaurea carniolica", "authorship": "Host" }, { "name": "Centaurea denticulata", "authorship": "Lej." }, { "name": "Centaurea dubia subsp. dubia", "authorship": null }, { "name": "Centaurea dubia subsp. nigrescens", "authorship": "(Willd.) Hayek" }, { "name": "Centaurea dubia subsp. smolinensis", "authorship": "(Hayek) Hayek" }, { "name": "Centaurea dubia subsp. vochinensis", "authorship": "(Bernh. ex Rchb.) Hayek ex Hegi" }, { "name": "Centaurea dubia subsp. vochinensis", "authorship": "(Bernh. ex Rchb.) Hayek" }, { "name": "Centaurea jacea subsp. nigrescens", "authorship": "(Willd.) Čelak." }, { "name": "Centaurea jacea subsp. transalpina", "authorship": "(DC.) R.C.V.Douin" }, { "name": "Centaurea kochii", "authorship": "F.Schultz ex Nyman" }, { "name": "Centaurea neapolitana", "authorship": "Boiss." }, { "name": "Centaurea nigrescens subsp. pinnatipartita", "authorship": "(Fiori) Dostál" }, { "name": "Centaurea nigrescens var. nigrescens", "authorship": null }, { "name": "Centaurea nigrescens var. rotundifolia", "authorship": "Bartl." }, { "name": "Centaurea nigrescens var. vochinensis", "authorship": "W.D.J.Koch" }, { "name": "Centaurea ramosa", "authorship": "(Gugler) Hayek" }, { "name": "Centaurea rotundifolia", "authorship": "(Bartl.) Hayek" }, { "name": "Centaurea schemnitzensis", "authorship": "hort. ex Steud." }, { "name": "Centaurea sciaphila", "authorship": "Vuk." }, { "name": "Centaurea serotina", "authorship": "Boreau" }, { "name": "Centaurea smolinensis", "authorship": "Hayek" }, { "name": "Centaurea spathulata", "authorship": "Ten." }, { "name": "Centaurea subcordata", "authorship": "Freyn & Sint." }, { "name": "Centaurea transalpina", "authorship": "Schleich. ex DC." }, { "name": "Centaurea trapezuntina", "authorship": "Boiss." }, { "name": "Centaurea tubulosa", "authorship": "Chab. ex Nyman" }, { "name": "Centaurea vochinensis", "authorship": "Bernh. ex Rchb." }, { "name": "Centaurea vochinensis f. pinnatifida", "authorship": "Fiori" }, { "name": "Centaurea vochinensis f. vochinensis", "authorship": null }, { "name": "Cyanus nigrescens", "authorship": "J.Presl & C.Presl" }, { "name": "Jacea carniolica", "authorship": "(Host) Holub" }, { "name": "Jacea neapolitana", "authorship": "(Boiss.) Holub" }, { "name": "Jacea nigrescens", "authorship": "(Willd.) Soják" }, { "name": "Jacea nigrescens subsp. nigrescens", "authorship": null }, { "name": "Jacea nigrescens subsp. transalpina", "authorship": "(Schlech. ex De Candolle) Soják" }, { "name": "Jacea smolinensis", "authorship": "(Hayek) Holub" } ], "wikipedia": "https://en.wikipedia.org/wiki/Centaurea_nigrescens" }, "photographs": { "shown": 8, "usable_found": 321, "licences": [ "CC0", "CC-BY", "CC-BY-SA" ], "noncommercial_excluded": true, "items": [ { "photo_id": 203040780, "license": "CC0", "license_name": "CC0 1.0", "license_url": "https://creativecommons.org/publicdomain/zero/1.0/", "derivatives_restricted": false, "creator": "mefisher", "creator_url": "https://www.inaturalist.org/people/mefisher", "source_url": "https://www.inaturalist.org/observations/bfc41fe5-20b2-43ba-a56d-f5041cd231f2", "observed_on": "2022-06-03", "lat": 38.605, "lon": -77.273, "original": { "width": 1024, "height": 768 }, "widths": [ 400, 800 ], "urls": { "avif": { "400": 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"attribution": "mefisher, CC0 1.0, via iNaturalist" } ] }, "native_range": { "scheme": "TDWG World Geographical Scheme for Recording Plant Distributions, level 3", "source": "Kew, World Checklist of Vascular Plants (WCVP v16)", "license": "CC BY 3.0", "excludes": [ "introduced", "extinct", "location_doubtful" ], "codes": [ "AUT", "BUL", "FRA", "GER", "HUN", "ITA", "YUG", "POL", "ROM", "SWI" ], "regions": [ { "code": "AUT", "name": "Austria", "continent": "EUROPE", "region": "Middle Europe" }, { "code": "BUL", "name": "Bulgaria", "continent": "EUROPE", "region": "Southeastern Europe" }, { "code": "FRA", "name": "France", "continent": "EUROPE", "region": "Southwestern Europe" }, { "code": "GER", "name": "Germany", "continent": "EUROPE", "region": "Middle Europe" }, { "code": "HUN", "name": "Hungary", "continent": "EUROPE", "region": "Middle Europe" }, { "code": "ITA", "name": "Italy", "continent": "EUROPE", "region": "Southeastern Europe" }, { "code": "YUG", "name": "NW. Balkan Pen.", "continent": "EUROPE", "region": "Southeastern Europe" }, { "code": "POL", "name": "Poland", "continent": "EUROPE", "region": "Middle Europe" }, { "code": "ROM", "name": "Romania", "continent": "EUROPE", "region": "Southeastern Europe" }, { "code": "SWI", "name": "Switzerland", "continent": "EUROPE", "region": "Middle Europe" } ] }, "phenology": { "n": 397, "n_annotated": 407, "sufficient": true, "by_month": [ 0, 0, 0, 0, 12, 23, 79, 121, 84, 53, 23, 2 ], "annotated_by_month": [ 0, 1, 1, 0, 13, 26, 81, 121, 85, 54, 23, 2 ], "share": [ null, null, null, null, 0.9231, 0.8846, 0.9753, 1, 0.9882, 0.9815, 1, null ], "ci": [ null, null, null, null, [ 0.6669, 0.9863 ], [ 0.7102, 0.96 ], [ 0.9144, 0.9932 ], [ 0.9692, 1 ], [ 0.9363, 0.9979 ], [ 0.9023, 0.9967 ], [ 0.8569, 1 ], null ], "peak_month": 8, "peak_basis": "share", "min_month_n": 5, "doi": "10.15468/dl.cgje2x", "source": "GBIF SQL download of iNaturalist Research-grade Observations", "quality_grade": "research (guaranteed upstream by iNaturalist at export)", "fields": { "by_month": "observations found IN FLOWER, by month (Jan..Dec)", "annotated_by_month": "observations in which a human recorded the reproductive state at all, by month. This is the denominator, and it includes the records that said \"no flowers or fruits\".", "share": "by_month / annotated_by_month. null where too few plants were examined to state a proportion.", "ci": "95% Wilson score interval on share.", "peak_month": "the month with the highest SHARE, not the highest count." } }, "traits": { "lifeform": "perennial", "climate": "temperate" }, "climate_envelope": { "mean_annual_temp_c": { "p5": 5.6, "median": 12, "p95": 14.4 }, "temp_seasonality": { "p5": 645.8, "median": 741.3, "p95": 923.6 }, "max_temp_warmest_month_c": { "p5": 19.7, "median": 26.7, "p95": 30.8 }, "min_temp_coldest_month_c": { "p5": -10.7, "median": -3.3, "p95": 0.2 }, "annual_precip_mm": { "p5": 714.9, "median": 1089.9, "p95": 1772.2 }, "precip_seasonality": { "p5": 10.2, "median": 27.2, "p95": 39.5 }, "precip_driest_quarter_mm": { "p5": 111.7, "median": 181.6, "p95": 283 }, "n": 1792, "units": { "mean_annual_temp_c": "degrees Celsius", "min_temp_coldest_month_c": "degrees Celsius (mean daily MINIMUM of the coldest month)", "max_temp_warmest_month_c": "degrees Celsius (mean daily MAXIMUM of the warmest month)", "annual_precip_mm": "millimetres per year", "precip_driest_quarter_mm": "millimetres in the driest quarter" }, "source": "CHELSA V2.1 climatologies 1981-2010, 30 arcsec", "citation": "Karger, D.N. et al. (2017) Climatologies at high resolution for the earth's land surface areas. Scientific Data 4, 170122.", "occurrences": "iNaturalist Research-grade Observations", "occurrences_doi": "10.15468/dl.cgje2x", "method": "Climate sampled at every georeferenced research-grade observation of the species. Reported as the 5th to 95th percentile across 1792 of them. Species with fewer than 30 georeferenced observations get no envelope.", "is_hardiness_zone": false, "hardiness_zone_note": "min_temp_coldest_month_c is NOT a USDA hardiness zone. A USDA zone is the average annual EXTREME minimum temperature; this is the mean daily minimum of the coldest month, which is typically about 16 C warmer. Do not present one as the other." }, "identification": { "on_device_model": { "model": "Google AIY plants V1 (TFLite, 2,102 classes)", "identifies_this_species": false }, "in_accuracy_benchmark": false, "benchmark_url": "https://botanai.app/accuracy/", "confused_with": [] }, "sources": [ { "name": "World Flora Online Plant List", "note": "accepted name, authority, classification", "license": "CC0", "url": "https://www.worldfloraonline.org/", "retrieved": "2026-07-12" }, { "name": "iNaturalist", "note": "photographs and flowering annotations, CC0 / CC BY / CC BY-SA only", "license": "per photograph", "url": "https://www.inaturalist.org/", "retrieved": "2026-06-27" }, { "name": "Wikidata", "note": "common name (P1843), joined on the World Flora Online identifier (P7715)", "license": "CC0", "url": "https://www.wikidata.org/", "retrieved": "2026-07-13" }, { "name": "Kew, World Checklist of Vascular Plants (WCVP v16)", "note": "native distribution by TDWG level-3 botanical country, and life form", "license": "CC BY 3.0", "url": "https://doi.org/10.15468/6h8ucr", "retrieved": "2026-06-04" } ], "gaps": [ { "field": "care", "status": "not_published", "reason": "Not published anywhere on this site. Every care claim we could make cheaply would be an unsourced enum, which is what the previous version of this site did and why it was deleted." }, { "field": "toxicity", "status": "not_published", "reason": "Not published. The widely copied list is a copyrighted compilation restricted to noncommercial use, and we will not scrape it. A sourced toxicity dataset is being built from primary literature and is not ready." }, { "field": "botanical_review", "status": "not_sourced", "reason": "No page on this site has been reviewed by a named botanist. The determination label says so, on every page." }, { "field": "hardiness_zone", "status": "not_published", "reason": "Not published for any species. A USDA hardiness zone is the average annual EXTREME minimum temperature, and we hold the mean daily minimum of the coldest month, which is a different quantity and typically about 16 C warmer. Presenting one as the other would place a plant several zones too warm, so we do not publish a zone at all." } ], "license": { "data": "CC BY 4.0", "attribution": "BotanAI, https://botanai.app/plants/centaurea-nigrescens/", "note": "This document is licensed CC BY 4.0. The PHOTOGRAPHS it links are licensed individually and separately: each carries its own license and license_url, and those terms govern. Underlying taxonomy is CC0 (World Flora Online); native range is CC BY 3.0 (Kew)." } }