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Pictured: Medicago sativa — the species. This subspecies isn’t separately illustrated.
Fabaceae family

Alfalfa (subsp. sativa) Medicago sativa subsp. sativa subspecies

Alfalfa (subsp. sativa) is an introduced annual herb, found in Alaska, Canada, and Hawaii.

⚠ Invasive here — plant a native instead USDA + GBIF

Alfalfa (subsp. sativa) is flagged invasive in the U.S. These natives fill a similar niche — same growth habit, bloom season, height, and region — so you keep the look and feed local wildlife instead of spreading a problem.

Common Milkweed
Native ★
Common Milkweed
Asclepias syriaca
●●●●●
Swamp Milkweed
Native ★
Swamp Milkweed
Asclepias incarnata
●●●●●
Butterfly Weed
Native ★
Butterfly Weed
Asclepias tuberosa
●●●●●
New England Aster
Native ★
New England Aster
Symphyotrichum novae-angliae
●●●●●
Matched on growth habit · bloom months · mature height · shared U.S. range (USDA + GBIF) — a starting point, not a prescription.

Growing & care

USDA PLANTS · TRY
Conditions
Sources · Conditions
Cold hardiness (derived) — Hardiness
Hardiness
≥ zone 4 derived from its U.S. range
Size & form
Sources · Size & form
USDA PLANTS — Lifespan
Lifespan
Annual
In the garden
Herb layer — Sits in the herb of a layered food forest or polyculture.Open guide →
derived roles
Species characteristics from USDA PLANTS (public domain) + TRY (CC BY) — general guidance, not a guarantee for your exact site. Deer "browsing" is documented palatability, not a deer-proof claim.

Wildlife & pollinators

How pollinator value is scored →
❧ Caterpillar hosts ~69 caterpillar species

Medicago supports ~69 caterpillar species.

Native butterfly & moth caterpillars are the base of the terrestrial food web — most songbirds rear their young almost entirely on them. As a host for native Lepidoptera this is a strong genus for introduced plants — native genera typically support far more.

Recorded feeding on Medicago in North America, including:

Achyra rantalis · Garden Webworm Moth Achyra similalis · snout moth Actebia fennica · owlet moth Agnorisma badinodis · Pale-Banded Dart Agrotis orthogonia · Pale Western Cutworm Agrotis venerabilis · Venerable Dart
+ 8 more species →
Agrotis vetusta · Old Man Dart Anacamptodes humaria · geometer (inchworm) moth Anagrapha falcifera · Celery Looper Anticarsia gemmatalis · owlet moth Apamea devastator · Glassy Cutworm Aphelia alleniana · Wide-Striped Leafroller Arachnis picta · Painted Tiger Moth Archips argyrospila · Fruit-Tree Leafroller Moth
Keystone count (genus-level) from Warren II 2026 (CC0) · Tallamy host-use records. Named species (a documented Nearctic sample, not exhaustive) from NHM HOSTS (CC0).
Species thumbnails re-hosted from iNaturalist — Creative Commons, credited per image (hover for credit). Click any species to see it on iNaturalist. Not exhaustive; many taxa have no openly-licensed photo yet.
Sources for this entry (11) Open & cited
[01] Scientific name & family — USDA PLANTS (DwCA, Zenodo 17903503)
[02] Growth habit & duration — USDA PLANTS (DwCA, Zenodo 17903503)
[03] Native status & distribution — USDA PLANTS (DwCA, Zenodo 17903503)
[04] Common name — USDA PLANTS (via GBIF)
[05] Invasive / introduced status — US-RIIS v2.0 (USGS)
[06] Ecological value — Warren II 2026 (CC0) · Tallamy host-use counts
[07] Cold hardiness (derived) — Derived from U.S. range × USDA PHZM zones
[09] Caterpillar host count — Warren II 2026 (Dryad, CC0) · Tallamy host-use counts
[10] Caterpillar species — NHM HOSTS (CC0)
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PlantKey’s data is open under CC BY-SA 4.0 — free to reuse and adapt, with attribution and the same licence. Photos keep their own per-image licence + credit (see Sources above).

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