Bloomipedia
Rattail (Stachytarpheta cayennensis)
Photo: nmoorhatch via iNaturalist · CC BY 4.0 · resized

Flower profile

Rattail

Stachytarpheta cayennensis

Rattail is a flowering plant. In Hawaii it's most often seen in bloom in January–December.

0states
1,597HI sightings*
2,130U.S. sightings*

*iNaturalist research-grade observations, as of October 17, 2026.

On our lists for: Hawaii

Quick look

Stachytarpheta cayennensis is a species of flowering plant in the verbena family known by many English language common names, including blue snakeweed, Cayenne snakeweed, dark-blue snakeweed, bluetop, nettle-leaf porterweed, rattail, rough-leaf false vervain, blue rat's tail, Brazilian tea, Cayenne vervain, false verbena, joee, nettleleaf velvetberry, and Cayenne porterweed.

  • It belongs to the Verbenaceae family. iNaturalist
  • USDA PLANTS describes it as a shrub with a perennial life cycle. USDA PLANTS
  • In Hawaii, most iNaturalist sightings of it in flower come in January–December. iNaturalist
  • iNaturalist has 1,597 research-grade sightings of it in Hawaii, ranking #22 among the 105 flowers on our Hawaii list. iNaturalist

Rattail gift ideas

Handmade rattail gifts from independent makers.

When does it bloom?

In Hawaii, most flowering sightings come in January–December.

Flowering records by month in Hawaii (iNaturalist research-grade observations marked “Flowering”) (50 records)

Conservation status

Federal (U.S. ESA)
Not listed No U.S. Endangered Species Act listing in the USFWS ECOS database. USFWS ECOS
NatureServe global
GNR Not yet ranked worldwide. NatureServe
Hawaii
Not listed Not on Hawaii threatened and endangered plants (HAR 13-107; the state list follows the federal list), DLNR Division of Forestry and Wildlife. NatureServe has no Hawaii rank for it. HAR 13-107
Rare elsewhere
No other U.S. state ranks it S1, S2, SH or SX.

Checked October 17, 2026. Rankings and lists can change, so follow the links for the latest.

Can you eat it?

For peopleNot well documented

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.

For petsNot well documented

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 has no state-by-state distribution for this name, so we can't map it yet.

More Hawaii flowers

Sources