{"schema":"https://ver.cy/schemas/card/1.0.0","id":"vr.tr.corylus-avellana","code":"thing-q124969","url":"https://ver.cy/models/thing/q124969/","name":"Corylus avellana","alternateNames":[],"kind":"thing","status":"published","version":"0.1.0-research.1","language":"en","classifiers":{"family":"Thing Registry","category":"Physical world and living systems","entryKind":"thing","plane":"PHY","domain":["PHY.LIV"],"industry":[],"navPath":"","tags":[],"facets":{}},"whatItIs":"Corylus avellana is a monoecious, wind-pollinated deciduous shrub or small tree in the birch family (Betulaceae), native from Atlantic Europe to the Caucasus and western Asia, that bears edible nuts in a leafy involucre and is the principal European source of cultivated hazelnuts as well as a traditional coppice and hedgerow species.","purpose":"Enable an agent to recognise Corylus avellana, assess a particular plant or stool, and choose evidence-based observation, cultivation, propagation or harvesting actions.","scope":{"in":["Species identification, supporting observations and uncertainty about other Corylus species or cultivated ancestry","Plant, stool and stem boundaries, including coppice regrowth and attached suckers","Local leaf, flower and nut development and reproductive performance","Root-zone conditions, crown vitality and observed damage","Purpose-specific cultivation, coppicing, propagation and harvest readiness"],"out":["Other Corylus species and hybrids requiring their own identification","Whole woodland, hedgerow or orchard management","Detached hazelnut batches, food processing and food-safety certification","Pest and pathogen life cycles and treatment-product models","Timber products and manufactured coppice goods","Land ownership, statutory permissions and conservation designations beyond links constraining an action"],"boundaries":[]},"distinguishingFeatures":["Inspect mature fruit with its husk attached: a short husk exposing the nut supports C. avellana, whereas a long enclosing husk suggests C. maxima; cultivated material may require further evidence. [RHS cobnuts and filberts](https://www.rhs.org.uk/nuts/cobnuts-filberts)","Compare whole-plant habit and fruit husks with C. colurna: the latter typically forms a conical tree with deeply fringed husks; C. avellana typically forms a large shrub or small multi-stemmed tree. Training makes habit alone insufficient. [RHS C. colurna](https://www.rhs.org.uk/plants/4517/corylus-colurna/details) and [RHS C. avellana](https://www.rhs.org.uk/plants/4511/corylus-avellana-f/details)","Use rounded deciduous leaves, early-season yellow male catkins and subsequent nuts together to corroborate hazel identity against superficially similar broadleaved shrubs; this combination alone does not distinguish every Corylus species. [RHS C. avellana](https://www.rhs.org.uk/plants/4511/corylus-avellana-f/details)","Require diagnostic fruit or stronger provenance before accepting a sterile specimen as C. avellana rather than C. maxima; missing bracts can leave identification uncertain. [Kew specimen record](https://records.data.kew.org/occurrences/024201d7-3580-4fd0-9c0d-8c19864a52ea)"],"structure":{"bundles":[{"id":"hazel-identity","name":"Hazel identity","description":"Establish whether the observed plant belongs to this registry entry.","layers":[{"id":"diagnostic-organs","name":"Diagnostic organs","description":"Combine fruit, foliage and seasonal observations.","findings":[{"id":"species-evidence","name":"Species evidence","description":"Record the organs supporting identification and the alternatives they exclude.","questions":[{"text":"What do mature husk enclosure, husk lobing and nut dimensions indicate about C. avellana versus C. maxima or C. colurna?","id":"species-evidence-q01","kind":"definition"},{"text":"Which diagnostic organs were observed on this plant, when, and in which photographs or specimens?","id":"species-evidence-q02","kind":"provenance"},{"text":"What missing or conflicting character requires identification to remain provisional?","id":"species-evidence-q03","kind":"boundary"}]}]},{"id":"cultivated-identity","name":"Cultivated identity","description":"Separate botanical determination from cultivar labels and propagation history.","findings":[{"id":"cultivar-attribution","name":"Cultivar attribution","description":"Retain traceable identity claims without treating a commercial name as proof.","questions":[{"text":"Which supplier, accession or mother-plant record supports the cultivar and species attribution?","id":"cultivar-attribution-q01","kind":"provenance"},{"text":"Does unusual foliage, branch form or fruit morphology fit a documented cultivar, or require review of the identification?","id":"cultivar-attribution-q02","kind":"boundary"}]}]}]},{"id":"stool-and-regrowth","name":"Stool and regrowth","description":"Represent the persistent plant and its changing stems.","layers":[{"id":"plant-boundary","name":"Plant boundary","description":"Distinguish connected stems, detached offspring and graft components.","findings":[{"id":"stool-membership","name":"Stool membership","description":"Record what evidence joins stems into one observed plant.","questions":[{"text":"Which stems share an observed basal stool, and which nearby shoots have unverified connections?","id":"stool-membership-q01","kind":"boundary"},{"text":"For a grafted specimen, which observed shoots arise above or below the graft union?","id":"stool-membership-q02","kind":"measurement"}]}]},{"id":"coppice-response","name":"Coppice response","description":"Track stem cohorts and recovery after cutting.","findings":[{"id":"regrowth-capacity","name":"Regrowth capacity","description":"Assess the stool through dated cutting history and observed recovery.","questions":[{"text":"When was the stool last cut, and what records distinguish stool history from current stem age?","id":"regrowth-capacity-q01","kind":"provenance"},{"text":"How many live replacement shoots developed, and how have their length and basal diameter changed?","id":"regrowth-capacity-q02","kind":"measurement"},{"text":"Does observed recovery support another cut for the stated objective, or favour retaining stems and reassessing?","id":"regrowth-capacity-q03","kind":"action"}]}]}]},{"id":"flowering-and-nut-set","name":"Flowering and nut set","description":"Connect separate flowering observations to nut development.","layers":[{"id":"flowering-overlap","name":"Flowering overlap","description":"Record local reproductive timing without imposing a universal calendar.","findings":[{"id":"pollen-opportunity","name":"Pollen opportunity","description":"Evaluate whether suitable pollen could reach receptive flowers.","questions":[{"text":"On which dates were pollen shedding and female receptivity observed or assessed separately?","id":"pollen-opportunity-q01","kind":"measurement"},{"text":"Which nearby hazels have documented compatibility and overlapping pollen release?","id":"pollen-opportunity-q02","kind":"provenance"},{"text":"What additional observation is needed before attributing poor nut set to inadequate pollination?","id":"pollen-opportunity-q03","kind":"action"}]}]},{"id":"nut-development","name":"Nut development","description":"Separate fruit formation, kernel fill, damage and disappearance.","findings":[{"id":"crop-outcome","name":"Crop outcome","description":"Use dated samples to explain the difference between visible nuts and harvestable output.","questions":[{"text":"What proportions of a defined sample are developing, filled, empty or visibly damaged?","id":"crop-outcome-q01","kind":"measurement"},{"text":"What observations distinguish failure to develop from premature drop or animal removal?","id":"crop-outcome-q02","kind":"measurement"},{"text":"Which locally validated maturity indicators support harvest for the intended use?","id":"crop-outcome-q03","kind":"action"}]}]}]},{"id":"site-and-vitality","name":"Site and vitality","description":"Assess hazel performance against its immediate growing conditions.","layers":[{"id":"growing-conditions","name":"Growing conditions","description":"Relate root-zone and canopy exposure to the plant's objective.","findings":[{"id":"site-fit","name":"Site fit","description":"Record measured conditions and locally relevant performance evidence.","questions":[{"text":"What root-zone moisture, drainage, pH and crown light measurements accompany the current growth assessment?","id":"site-fit-q01","kind":"measurement"},{"text":"Did frost or dry conditions coincide with this plant's recorded flowering or nut-development stages?","id":"site-fit-q02","kind":"measurement"},{"text":"Which site adjustment is supported for this hazel's stated objective and observed limitation?","id":"site-fit-q03","kind":"action"}]}]},{"id":"damage-and-decline","name":"Damage and decline","description":"Separate symptoms from confirmed causes.","findings":[{"id":"condition-assessment","name":"Condition assessment","description":"Locate and track abnormal buds, foliage, stems and nuts before selecting a response.","questions":[{"text":"How extensive are enlarged buds, leaf coatings, shoot dieback, bark injury or nut holes, and how have they changed?","id":"condition-assessment-q01","kind":"measurement"},{"text":"What diagnostic evidence supports a pest, pathogen or environmental cause rather than a symptom-only label?","id":"condition-assessment-q02","kind":"provenance"},{"text":"Should the agent monitor, obtain a diagnostic sample or refer to a locally applicable treatment model?","id":"condition-assessment-q03","kind":"action"}]}]}]},{"id":"propagation-and-use","name":"Propagation and use","description":"Connect management objectives to interventions and their outcomes.","layers":[{"id":"propagation-choice","name":"Propagation choice","description":"Maintain traceability when producing another plant.","findings":[{"id":"offspring-identity","name":"Offspring identity","description":"Choose propagation according to whether seedling variation or preservation of an attributed cultivar is intended.","questions":[{"text":"Must the new plant preserve a documented cultivar, or is a seedling of recorded parentage acceptable?","id":"offspring-identity-q01","kind":"definition"},{"text":"What mother-plant and shoot-origin evidence supports the identity of the selected propagation material?","id":"offspring-identity-q02","kind":"provenance"},{"text":"What observed rooting and establishment criteria must be met before separating or transplanting vegetative material?","id":"offspring-identity-q03","kind":"action"}]}]},{"id":"intervention-choice","name":"Intervention choice","description":"Select actions using the plant's purpose, condition and linked constraints.","findings":[{"id":"management-decision","name":"Management decision","description":"Make the intended benefit and follow-up assessment explicit before altering the hazel.","questions":[{"text":"Is this plant being managed primarily for nuts, coppice stems, ornament, habitat or a documented combination?","id":"management-decision-q01","kind":"definition"},{"text":"What observed habitat use and linked permissions constrain pruning, coppicing or nut collection at this location?","id":"management-decision-q02","kind":"boundary"},{"text":"Which intervention is supported now, and what subsequent regrowth, flowering or crop observation will determine whether it succeeded?","id":"management-decision-q03","kind":"action"}]}]}]},{"id":"evidence-and-external-alignment","name":"Evidence and external alignment","description":"What the world already says about this thing, gathered so the model can be checked against it.","layers":[{"id":"reported-evidence","name":"Reported evidence","description":"Findings from the breadth pass, kept separate from the structural claims.","findings":[{"id":"evidence-kinds","name":"Kinds and varieties","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these kinds and varieties hold for the sense of Corylus avellana this model covers, and on what evidence?","id":"evidence-kinds-q01","kind":"provenance"}]},{"id":"evidence-identifiers","name":"Identifiers and schemes","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these identifiers and schemes hold for the sense of Corylus avellana this model covers, and on what evidence?","id":"evidence-identifiers-q01","kind":"provenance"}]},{"id":"evidence-standards-and-regulation","name":"Standards and regulation","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these standards and regulation hold for the sense of Corylus avellana this model covers, and on what evidence?","id":"evidence-standards-and-regulation-q01","kind":"provenance"}]},{"id":"evidence-real-world-use","name":"Real-world use","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these real-world use hold for the sense of Corylus avellana this model covers, and on what evidence?","id":"evidence-real-world-use-q01","kind":"provenance"}]},{"id":"evidence-measurements","name":"Typical measurements","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these typical measurements hold for the sense of Corylus avellana this model covers, and on what evidence?","id":"evidence-measurements-q01","kind":"provenance"}]},{"id":"evidence-failure-modes-and-hazards","name":"Failure modes and hazards","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these failure modes and hazards hold for the sense of Corylus avellana this model covers, and on what evidence?","id":"evidence-failure-modes-and-hazards-q01","kind":"provenance"}]},{"id":"evidence-regional-variation","name":"Regional variation","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these regional variation hold for the sense of Corylus avellana this model covers, and on what evidence?","id":"evidence-regional-variation-q01","kind":"provenance"}]},{"id":"evidence-neighbours","name":"Neighbouring kinds and how to tell them apart","description":"Reported by the breadth pass; each item needs checking against its source before it becomes normative.","questions":[{"text":"Which of these neighbouring kinds and how to tell them apart hold for the sense of Corylus avellana this model covers, and on what evidence?","id":"evidence-neighbours-q01","kind":"provenance"}]}]}]}]},"agentConduct":{"may":["Identify hazel and describe its growth, nuts and uses, citing botanical sources.","Advise on coppicing and care for the landowner who asks."],"mustNot":["Serve or recommend hazelnuts to someone without checking for nut allergy.","Cut or coppice hazel on land the agent is not authorized to work.","Plant or move hazel plants in breach of plant health rules."],"requiresHuman":["Felling or coppicing hedgerows and woodland that may be protected."]},"ethics":{"considerations":["Hazelnut allergy can cause severe reactions, so food uses need clear labelling.","Hazel coppices and hedges are habitat for wildlife such as dormice and birds."],"affectedParties":["People with nut allergies","Woodland wildlife","Growers and landowners"]},"owners":{"steward":"The landowner where it grows; orchards are run by their growers.","roles":[],"masterSystems":["Plant name databases"]},"relations":[{"target":"Q11992872","type":"parent","note":"registry parent class"}],"interaction":{"identity":{"applicability":"required","items":["Vercy registry: vr.tr.corylus-avellana","Wikidata: Q124969 (https://www.wikidata.org/wiki/Q124969)"]},"properties":{"applicability":"required","items":["Identification confidence: supported; provisional; conflicting; unresolved, with evidence","Cultivar and propagation origin: Named cultivar, mother plant, seed source and rootstock where documented; unknown permitted","Husk-to-nut relationship: Husk and nut length in mm, ratio, enclosure and lobe description at recorded maturity","Stool and stem architecture: Live stem count, basal diameters in cm, crown height and spread in m","Coppice history: Uncut; cut with date; resprouting; failed regrowth; unknown","Male and female flowering stages: Catkins: immature, shedding, spent; female flowers: not observed, visible, receptivity assessed, spent; dated separately","Potential pollen donor: Donor plant or cultivar, distance in m, flowering overlap and compatibility evidence","Nut development and kernel fill: Dated sample count; developing, filled, empty and damaged proportions in %","Root-zone and light exposure: Soil pH, moisture with method and depth, waterlogging duration in days, light exposure with method","Crown and bud condition: Dated observations of dieback, leaf symptoms, enlarged buds, browsing and stem injury, with extent"]},"recognition":{"applicability":"required","items":["A multi-stemmed shrub with rounded, toothed, softly hairy leaves.","Yellow catkins in late winter and nuts in leafy husks in autumn."]},"capabilities":{"applicability":"required","items":["Identify or provisionally identify a plant using attached diagnostic organs and provenance.","Monitor flowering, nut development and regrowth through repeated observations.","Evaluate planting conditions and potential pollen donors for a stated cultivation objective.","Plan pruning or coppicing from stool condition, past response and habitat constraints.","Select and document seed or vegetative propagation material according to identity requirements.","Assess attached nuts for harvest readiness and transfer harvested material to a separate batch record."]},"hazards":{"applicability":"required","items":["The nuts are a common cause of food allergy.","Pests and diseases can spread in orchards."]},"interfaces":{"applicability":"required","items":["International Code of Nomenclature for algae, fungi, and plants, International Association for Plant Taxonomy."]},"context":{"applicability":"required","items":["This species occurs in woodland understoreys, woodland margins, scrub and hedgerows, where it provides food and cover for wildlife.","It is cultivated for edible hazelnuts and managed as coppice for poles, stakes and woven fencing.","Individual plants are also encountered in gardens and habitat restoration projects, where their growth, flowering and nut production may be monitored."]}},"sources":[{"title":"Species Plantarum, vol. 2 - Carl Linnaeus, Laurentius Salvius, 1753","url":"","note":"Original Linnaean publication of Corylus avellana and the starting point for the accepted botanical name."},{"title":"New Flora of the British Isles, 4th ed. - Clive A. Stace, C & M Floristics, 2019","url":"","note":"British morphological diagnosis, distinction from Corylus maxima, and status as native coppice and hedgerow shrub."},{"title":"UNECE Standard DDP-03 concerning the marketing and commercial quality control of Inshell Hazelnuts - United Nations Economic Commission for Europe","url":"https://unece.org/trade/wp7/DDP-Standards","note":"Commercial identity of inshell hazelnuts, sizing, moisture and quality tolerances used in international trade."},{"title":"Regulation (EU) No 1169/2011 on the provision of food information to consumers - European Union","url":"https://eur-lex.europa.eu/eli/reg/2011/1169/oj","note":"Hazelnut as a named allergen that must be declared when used as an ingredient in foods sold in the EU."},{"title":"Hazelnuts (Corylus) in Genetic Resources of Temperate Fruit and Nut Crops - S. A. Mehlenbacher, Acta Horticulturae / ISHS, 1991","url":"","note":"Cultivar geography, orchard biology, and the practical importance of eastern filbert blight in C. avellana breeding."},{"title":"Wikidata item Q124969: Corylus avellana","url":"https://www.wikidata.org/wiki/Q124969","note":"identity and sense of the item"},{"title":"Wikipedia: Corylus avellana","url":"https://en.wikipedia.org/wiki/Corylus_avellana","note":"general description of the item"}],"openQuestions":["Which regional identification keys and taxonomic treatments best resolve C. avellana, C. maxima and cultivated material with intermediate characters?","What evidence is sufficient to establish clone boundaries where adjacent hazel stools may be connected but excavation or genetic testing is unavailable?","Which cultivar-specific compatibility records and local flowering observations can reliably support pollen-donor selection?","Which locally validated moisture, frost and heat thresholds distinguish impaired nut production from threats to plant survival?","Which regional diagnostic protocols and observed recovery data should govern intervention in declining or repeatedly coppiced stools?"],"resources":{"spec":"/models/things/publications/thing-q124969/spec.json"},"provenance":{"origin":"thing registry research (pass 2)","builtFrom":["models/things/publications/thing-q124969/spec.json"],"providers":["Codex","Grok"],"researchStatus":"unreviewed","generatedAt":"2026-09-07T14:37:56Z","builder":"tools/build_cards.py@1.0.0"},"completeness":{"sections":{"classifiers":"filled","whatItIs":"filled","purpose":"filled","distinguishingFeatures":"filled","structure":"filled","agentConduct":"filled","ethics":"filled","owners":"filled","relations":"filled","interaction.identity":"filled","interaction.properties":"filled","interaction.recognition":"filled","interaction.capabilities":"filled","interaction.hazards":"filled","interaction.interfaces":"filled","interaction.context":"filled","sources":"filled"},"notes":{"_gate":"Published through the thing publication gate 1.0 on 2026-10-07T10:10:25+00:00: completeness 1.00; sense: Wikidata description; 3 live sources; review by codex: pass"},"score":1.0}}