yam

Supported Dioscorea identification

Record the evidence supporting Dioscorea placement and any narrower identification, preserving unresolved alternatives.

1. Which observed leaf, stem, climbing, floral and storage-organ characters support the identification rather than sweet potato or another locally named yam? boundary
2. Which taxonomic reference supports the accepted name and authority, and which GBIF or NCBI identifiers can be matched to that exact taxon? provenance

Identity at the correct level

Associate each claim with an individual, propagule, accession, cultivar, population or taxon.

1. Does this record describe one growing plant, a planting tuber, a cultivated accession, a population or a taxon? definition
2. What evidence links the plant to its claimed cultivar or accession, and is its local name being mistaken for a formally established identity? provenance

Observed yam architecture

Document the vine, leaves, underground organs and any aerial bulbils using explicit observation methods.

1. What are the observed stem features, leaf arrangement and twining direction, and how was the viewing direction defined? measurement
2. Which underground storage organs or aerial bulbils are actually observed, and what remains unknown because excavation would damage the plant? measurement

Seasonal state with viability evidence

Distinguish expected senescence or dormancy from loss of viability using the plant's history and taxon-specific evidence.

1. What observations and dates establish sprouting, active vine growth, storage-organ development or senescence for this plant? measurement
2. What evidence distinguishes a viable dormant yam from a dead or rotting storage organ before watering, disposal or replanting? action

Observed reproductive capacity

Separate flowering, sexual expression, fruit formation and demonstrated seed viability.

1. Which flowers and sexual expression have actually been observed on this plant, and during which growth cycle? measurement
2. What evidence establishes compatible flowering partners, pollination and viable seed production for this taxon or accession? provenance

Suitable, traceable propagules

Evaluate whether available organs can regenerate and whether their identity and health are sufficiently established.

1. Which propagation method is supported for this identified yam, and does the proposed tuber, tuber portion or bulbil meet its viability requirements? action
2. Which parent plant or accession supplied the material, and what inspection or testing supports its recorded health status? provenance

Condition-based yam care

Use measured conditions and symptom history to choose interventions while preserving diagnostic uncertainty.

1. How do soil moisture, drainage, temperature, light and available climbing support compare with documented requirements for this yam and growth stage? measurement
2. Do vine yellowing, poor growth or storage-organ lesions warrant a cultivation adjustment, isolation or diagnostic sampling, and what evidence supports that choice? action

Place-specific stewardship

Anchor conservation and movement decisions to an identified taxon, a location and dated evidence.

1. What sources establish this taxon's native range, local occurrence status and any IUCN assessment category and year, without treating an unassessed yam as secure? provenance
2. What collection, plant-health or invasive-species constraints apply before this living yam or its bulbils and tubers are collected, moved or planted at the destination? action

Check these first

Recalled without web access and unsourced; every item is a lead to verify.

• With no recorded sense, this entry interprets 'yam' as true yam plants, not sweet potatoes or a single species.
• Verify species authorities, native ranges and database identifiers before creating species-level records; common names and cultivated group boundaries vary.
• Life history, sexual characteristics, toxicity and conservation assessments must be resolved by species; no single IUCN status or assessment year applies to this grouping.

1. Which of these check these first hold for the sense of yam this model covers, and on what evidence? provenance

Kinds and varieties

Recalled without web access and unsourced; every item is a lead to verify.

• White Guinea yam (Dioscorea rotundata)
• Yellow Guinea yam (Dioscorea cayenensis)
• Greater or water yam (Dioscorea alata)
• Lesser yam (Dioscorea esculenta)
• Chinese yam (Dioscorea polystachya)
• Trifoliate yam (Dioscorea dumetorum)

1. Which of these kinds and varieties hold for the sense of yam this model covers, and on what evidence? provenance

Identifiers and schemes

Recalled without web access and unsourced; every item is a lead to verify.

• International Code of Nomenclature for algae, fungi, and plants (ICN) - Dioscorea L.; species identified by binomial names - The genus includes plants beyond cultivated food yams; 'yam' does not identify one species.
• GBIF taxon key - Numeric identifier for a taxon record - Resolve the species before assigning a key.
• NCBI Taxonomy TaxID - Numeric taxonomic identifier - Species-specific identifiers require verification; no single species identifier represents all yams.

1. Which of these identifiers and schemes hold for the sense of yam this model covers, and on what evidence? provenance

Real-world use

Recalled without web access and unsourced; every item is a lead to verify.

• Cultivation as a staple carbohydrate crop.
• Cooking tubers by boiling, steaming, roasting or frying, with preparation requirements depending on species.
• Processing tubers into flour or pounded foods.
• Vegetative propagation using tubers, tuber pieces or, in some species, bulbils.
• Use in harvest festivals, gifts and ceremonial exchanges in some societies.

1. Which of these real-world use hold for the sense of yam this model covers, and on what evidence? provenance

Failure modes and hazards

Recalled without web access and unsourced; every item is a lead to verify.

• Some species and wild forms contain toxic or irritating compounds; edibility and safe preparation cannot be inferred from the common name.
• Misidentification can confuse edible cultivated yams with toxic wild Dioscorea species.
• Viruses can accumulate through repeated vegetative propagation.
• Nematode damage and fungal or bacterial rots can reduce yield and storage quality.
• Some introduced Dioscorea species can become invasive.

1. Which of these failure modes and hazards hold for the sense of yam this model covers, and on what evidence? provenance

Regional variation

Recalled without web access and unsourced; every item is a lead to verify.

• White and yellow Guinea yams are particularly associated with West African cultivation and food traditions.
• Dioscorea alata is widely cultivated across tropical regions, including Asia, the Pacific and the Caribbean.
• In North American food marketing, 'yam' may denote a sweet potato rather than a Dioscorea plant.

1. Which of these regional variation hold for the sense of yam this model covers, and on what evidence? provenance

Neighbouring kinds and how to tell them apart

Recalled without web access and unsourced; every item is a lead to verify.

• Sweet potato - Ipomoea batatas belongs to Convolvulaceae and produces storage roots; true yams belong to Dioscoreaceae and produce tubers.
• Potato - Solanum tuberosum is a solanaceous plant with stem tubers, outside the genus Dioscorea.
• Dioscorea - Dioscorea is a botanical genus; 'yam' is a common-name grouping whose scope varies and often emphasizes cultivated edible species.
• Yam tuber - The tuber is an organ harvested from the plant; this entry describes the plants rather than the harvested food product.

1. Which of these neighbouring kinds and how to tell them apart hold for the sense of yam this model covers, and on what evidence? provenance