PlantKey Open ecological atlas
Planner
Home / Browse / Justicia / Looseflower Water-willow
iNaturalist — CC, credited & licensed per image
Acanthaceae family

Looseflower Water-willow Justicia ovata

Native

Looseflower Water-willow is a perennial wildflower native to the lower 48 states. It blooms Apr – Aug.

Growing & care

USDA PLANTS · TRY
Conditions
Sources · Conditions
Cold hardiness (derived) — Hardiness
Hardiness
≥ zone 8 derived from its U.S. range
Size & form
Sources · Size & form
USDA PLANTS — Lifespan
McKenzie et al. 2025 — community-science image analysis (MIT) — Flower colour
Lifespan
Perennial
Flower colour
White AI AI image-analysis of community-science photos (~87% expert agreement) — not a botanical record
In the garden
Herb layer — Sits in the herb of a layered food forest or polyculture.Open guide →
Rain garden / bioswale — Rated OBL on the wetland list — tolerates wet feet, so it suits the soggy zone of a rain garden or bioswale that catches and filters runoff.Open guide →
derived roles
AI = read by an AI vision model · DERIVED = a computed estimate, not a direct measurement. The “How we know this” section below details each.
The garden year bloom → fruit → fall colour
J
F
M
A
M
J
J
A
S
O
N
D
Bloom
Bloom (the flower's colour)
Bloom · Apr – Aug — 77 obs · Herbarium specimens — Park et al. 2023 (CC BY 4.0)
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 ~5 caterpillar species

Justicia supports ~5 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 modest genus.

Recorded feeding on Justicia in North America, including:

Anthanassa frisia · Cuban Crescent ✦ Anthanassa texana · Texan Crescent ✦ Anartia jatrophae · White Peacock Argyrogramma verruca · Golden Looper Cobubatha dividua · owlet moth Dymasia dymas · brush-footed butterfly
+ 2 more species →
Ozarba aeria · owlet moth Siproeta stelenes · Malachite
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). ✦ = recorded on this exact species.
Wildlife & visitors 1 nectaring

Open records of who else uses Looseflower Water-willow — a generalist food-web signal, kept separate from the keystone Ecological Value.

1 adult butterfly & moth species is recorded nectaring at its flowers:

Tripudia flavofasciata
Interaction records (observations, not exhaustive) from GloBI → (CC0). Counts are distinct species; names are the most-recorded. Common names from Wikidata (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.
Frequently grows with

Across 61 U.S. vegetation-survey plots that recorded Looseflower Water-willow, these catalog species turned up most often in the same plot — a real field co-occurrence signal, not a planting prescription.

Eastern Poison Ivy · 89% Red Maple · 85% Sweetgum · 80% Smallspike False Nettle · 77% Trumpet Creeper · 75% Muscadine · 74% Green Ash · 70% Laurel Oak · 62%
"%" = share of this plant's plots that also held the species. From sPlotOpen → (Sabatini et al. 2021, CC BY 4.0) — open vegetation plots: wild community composition, not garden design.
How we know this (1) Methods & honest limits
Flower colour Derived

McKenzie et al. assigned each species a flower colour with a GPT-4V vision model over iNaturalist photos. We use the confident tier plus a separately-labelled lower-confidence top-up (mostly inconspicuous green/brown flowers), and render it as a small tint — never as an asserted fact, and kept out of the written synopsis.

Honest limits: AI image inference (~87% expert agreement on the confident tier); a decorative, confidence-tiered indicator, not a measured trait.

McKenzie, P., Berardi, A.E., Hopkins, R. (2025). flower_color_phenology (MIT).
Derived values are computed from open data by a published method — labelled, cited, and never shown as a direct observation. Full methodology →
Sources for this entry (16) 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] Wetland indicator — USACE National Wetland Plant List (2022)
[08] Ecological value — Warren II 2026 (CC0) · Tallamy host-use counts
[10] Conservation rank — NatureServe Explorer (CC BY)
[11] Cold hardiness (derived) — Derived from U.S. range × USDA PHZM zones
[12] Wildlife & visitors — GloBI — Global Biotic Interactions (CC0)
[14] Caterpillar host count — Warren II 2026 (Dryad, CC0) · Tallamy host-use counts
[15] 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…