PlantKey Open ecological atlas
Planner
Home / Browse / Astragalus / Thickpod Milkvetch (var. pachypus)
iNaturalist — CC, credited & licensed per image
Pictured: Astragalus pachypus — the species. This variety isn’t separately illustrated.
Fabaceae family

Thickpod Milkvetch (var. pachypus) Astragalus pachypus var. pachypus variety

Native Specialist-bee host

Thickpod Milkvetch (var. pachypus) is a perennial wildflower native to the lower 48 states. A host for pollen-specialist native bees.

More about this plant

Astragalus pachypus is a species of milkvetch known by the common name thickpod milkvetch. It is endemic to California, where it is known from many types of open habitat across the southern half of the state. This is a robust perennial herb forming stands of tough, wiry stems up to 80 centimeters tall. Leaves are up to about 16 centimeters long and are made up of many narrow leaflets. The plant flowers in inflorescences of 4 to 28 cream-colored flowers. The fruit is a sharp-beaked legume pod up to about 3 centimeters long which dries to a leathery, mostly hairless texture. There are two varieties of this species. The rarer, Jaeger's bush milkvetch, is known mostly from western Riverside County. Wikipedia →

Growing & care

USDA PLANTS · TRY
Conditions
Sources · Conditions
Cold hardiness (derived) — Hardiness
Hardiness
≥ zone 11 derived from its U.S. range
Size & form
Sources · Size & form
USDA PLANTS — Lifespan
Lifespan
Perennial
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 ~15 caterpillar species

Astragalus supports ~15 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 moderate genus.

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).
✦ Bees specialist-bee host

Specialist native bees depend on it.

Some native bees are pollen specialists (oligolectic) — they raise young only on pollen from particular plant genera. Astragalus is a recorded specialist-bee host, so losing it can mean losing the bee that relies on it.

Specialist hosts from Smith et al. 2024.
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 (12) 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 — USDA PLANTS (DwCA, Zenodo 17903503) — native status
[06] Description — Wikipedia (CC BY-SA)
[07] Ecological value — Warren II 2026 (CC0) · Tallamy host-use counts · Smith et al. 2024 (CC BY)
[08] Conservation rank — NatureServe Explorer (CC BY)
[09] Cold hardiness (derived) — Derived from U.S. range × USDA PHZM zones
[10] Caterpillar host count — Warren II 2026 (Dryad, CC0) · Tallamy host-use counts
[11] Caterpillar species — NHM HOSTS (CC0)
Spot an error or have a better photo? Every field links to its source, and the whole dataset is open.
Cite this page Open data, please attribute

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).

Citation

Loading…

BibTeX
Loading…