Flower profile
Hartweg's climbing milkweed
Funastrum heterophyllum
Hartweg's climbing milkweed is a wildflower that USDA PLANTS lists as native in the lower 48 states. In Arizona it's most often seen in bloom in March–October.
*iNaturalist research-grade observations, as of October 17, 2026.
On our lists for: Arizona
Quick look
Funastrum cynanchoides, also known as fringed twinevine, twining milkweed or climbing milkweed, is a perennial plant in the family Apocynaceae that grows twining through other plants in the Mojave Desert and Sonoran Desert. It has milky sap and smells pungent. It is similar to Funastrum hirtellum.
- It belongs to the Apocynaceae family. iNaturalist
- USDA PLANTS describes it as an herb (forb) / a vine with a perennial life cycle. USDA PLANTS
- USDA PLANTS lists it as native in the lower 48 states and records it in 6 states. USDA PLANTS
- NatureServe lists it as native to Arizona. NatureServe
- In Arizona, most iNaturalist sightings of it in flower come in March–October. iNaturalist
- iNaturalist has 1,849 research-grade sightings of it in Arizona, ranking #51 among the 109 flowers on our Arizona list. iNaturalist
Hartweg's climbing milkweed gift ideas
Handmade hartweg's climbing milkweed gifts from independent makers.
🌱 Sample spot. Handmade gift picks from independent shops will appear here once our shop partnership is approved. These cards are placeholders, not real products.
-
Placeholder
Hartweg's climbing milkweed art print
-
Placeholder
Hartweg's climbing milkweed greeting card
-
Placeholder
Hartweg's climbing milkweed mug
-
Placeholder
Hartweg's climbing milkweed earrings
-
Placeholder
Hartweg's climbing milkweed embroidery pattern
-
Placeholder
Hartweg's climbing milkweed sticker
When does it bloom?
In Arizona, most flowering sightings come in March–October.
Conservation status
- Federal (U.S. ESA)
- Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. USFWS ECOS
- NatureServe global
- T5 See NatureServe for what T5 means. NatureServe
- Arizona
- Not listed Not on Arizona Native Plant Law protected plants (Ariz. Admin. Code R3-3 Art. 11, App. A, eff. Feb. 2, 2025). NatureServe: SNR, not yet ranked in Arizona. AAC R3-3 App. A
- Rare elsewhere
- Other states where NatureServe ranks it rare or missing: NV (S2), UT (S2). (S1 critically imperiled, S2 imperiled, SH possibly extirpated, SX presumed extirpated.)
Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.
Can you eat it?
None of the sources we checked (NC State Extension (no page for this plant), USDA PLANTS) say whether it's edible or poisonous for people.
It isn't on the ASPCA plant list.
🌿 Never eat a wild plant unless you're certain of its ID; this isn't medical advice. Worried about a person? Call Poison Control at 1-800-222-1222. Worried about a pet? Call your vet.
Where does it grow?
USDA PLANTS records hartweg's climbing milkweed in 6 states.
recorded by USDA PLANTS on our state lists not recorded
See the full list of states
Arizona, California, Nevada, New Mexico, Texas, Utah.
Arizona counties with USDA records: Cochise, Coconino, Gila, Graham, La Paz, Maricopa, Mohave, Navajo, Pima, Pinal, Santa Cruz, Yavapai, Yuma.
More Arizona flowers
Sources
- USDA, NRCS. PLANTS Database, profile FUCYH.
- iNaturalist, Funastrum heterophyllum: taxonomy, research-grade observation counts and “Flowering” annotations, retrieved October 17, 2026.
- Wikipedia, Funastrum cynanchoides (lead quoted under CC BY-SA 4.0).
- Arizona: Arizona Native Plant Law protected plants (Ariz. Admin. Code R3-3 Art. 11, App. A, eff. Feb. 2, 2025).
- Arizona: Arizona prohibited noxious weeds (Ariz. Admin. Code R3-4-245).
- USFWS, ECOS species database (ESA listing check), October 17, 2026.
- NatureServe Explorer, Funastrum heterophyllum (global and state ranks).
- Edibility and toxicity: no source found (marked "not well documented").
- Photo: Isaac Ethington via iNaturalist · CC BY 4.0 · resized.