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DIY Agriculture

Amaranth — Biology

Metadata research draftEvidence limits

⚠️ Status: drafted from the literature survey (research/amaranth-seeds/report.md). The points below are paper-existence/coverage notes, not numeric claims. All Unknown until source notes and full-text claims are registered (see docs/methodology/evidence.md).

Taxonomy

Section titled “Taxonomy”
  • Family: Amaranthaceae. Evidence: Known (basic biology).
  • Grain amaranths: Amaranthus hypochondriacus, A. cruentus, A. caudatus (the grain/“huauhtli” group). A. tricolor and A. dubius are mainly leafy/vegetable types; related wild species (e.g. A. retroflexus, A. quitensis) are weeds — do not confuse. Evidence: Known for species identity; wild/weedy separation needs sources.
  • Two chromosome-level genomes exist for the grain types (A. hypochondriacus 2014, A. cruentus 2021) — candidate split for corroboration. DOI candidates: 10.1093/dnares/dsu021 (2014), 10.1111/tpj.15298 (2021).

Growth habit

Section titled “Growth habit”
  • Grain amaranth: annual, herbaceous, single erect stem with a terminal panicle/inflorescence (a compact flower head that matures into a dense seed head). Growth form (erect, monoecious/still a grain pseudocereal, C4 photosynthetic metabolism). Evidence: Known generally; cultivar-specific height/panicle traits source-tagged.
  • Plant height and panicle size vary widely by species and cultivar — value Unknown until specific sources.

Root system

Section titled “Root system”
  • Fibrous; amaranth is noted for relative drought tolerance (C4, efficient water use) — but root depth and exact water relations are Unknown until sources (see irrigation.md).

Lifecycle

Section titled “Lifecycle”
  • Annual. Days to anthesis/flowering and to physiological seed maturity depend on thermal/moisture environment and daylength; ranges Unknown until sources. Phenology papers exist (10.47815/apsr.2021.10033, 10.1515/johr-2016-0025).

Flowering and seed set

Section titled “Flowering and seed set”
  • Flowers in a terminal panicle; grain is produced in very many small utricles. Flowering/anthesis timing and its drivers (photoperiod, temperature) are a research area — Unknown/partial.
  • Seed development: tiny (1–2 mm), lens-shaped, pale cream to light brown in grain types. Seed size is a key human-scale processing property.

Photoperiod

Section titled “Photoperiod”
  • Reported to be quantitative short-day or daylength-sensitive depending on accession, but behavior is inconsistent across sources — treat as Conflicting / Unknown until resolved with cultivar separately (as done for chia). This is a flagged nuance; record genotype-by-genotype.

Seed traits relevant to human-scale use

Section titled “Seed traits relevant to human-scale use”
  • Tiny seed (larger than amaranth’s close analog is still small) — relevant to sowing, threshing, cleaning.
  • Seed is a true grain pseudocereal: high-quality protein (lysine-rich), starch — contrast with chia’s oily seed. End-use: whole, popped, or flour. See processing.md.

Open questions → open-questions.md

Section titled “Open questions → open-questions.md”
  • Photoperiod × cultivar behavior at home-garden latitudes; panicle uniformity (shattering at maturity); exact seed size/1,000-seed weight for grain types.