Stachytarpheta cayennensis
naturalizedVerbenaceae

Stachytarpheta cayennensis

Rattail

Naturalized (non-native)non-native

Introduced and now reproducing on its own in the wild.

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. Names in other languages include honagasō (Japanese), gervão-urticante (Brazilian Portuguese), piche de gato, rabo de zorro (Spanish), herbe á chenille, herbe bleue, queue de rat (French), ōi, ōwī...

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Seasonality
67 flowering · 0 fruiting annotations · iNaturalist · fetched Jul 2026
JFMAMJJASONDpeak
■ flowering (peak June)■ fruiting (peak January)

This is an inference, not a schedule. The curve reflects when observers annotated flowering and fruiting — which tracks observer effort as well as plant behavior, and pools all elevations and islands into one signal. Hawaiʻi’s microclimates vary enormously; a species may fruit in January at sea level and June at elevation. Use this to know when to look, then look.

Gallery · 8 · iNaturalist
open-licensed photos · click any to view its source
Where documented · 90 ahupuaʻa
documented occurrences · iNaturalist + GBIF · iNaturalist 199 · GBIF 292 records
Waikīkī · OʻahuiNat 16 · GBIF 37 ✓
Hāʻena · KauaʻiiNat 18 · GBIF 28 ✓
Wailua · KauaʻiiNat 21 · GBIF 24 ✓
Kahakuloa · MauiiNat 13 · GBIF 15 ✓
ʻAlaeiki · MauiiNat 9 · GBIF 12 ✓
Waimea · KauaʻiiNat 7 · GBIF 11 ✓
Honopou · MauiiNat 7 · GBIF 11 ✓
Hanalei · KauaʻiiNat 6 · GBIF 11 ✓
Kāneʻohe · OʻahuiNat 5 · GBIF 7 ✓
Pololū · HawaiʻiiNat 4 · GBIF 8 ✓
Kuliʻouʻou · OʻahuiNat 5 · GBIF 6 ✓
Kapaʻa · KauaʻiiNat 5 · GBIF 6 ✓
Honolulu · OʻahuiNat 4 · GBIF 6 ✓
Kailua · OʻahuiNat 5 · GBIF 4 ✓
South Olohena · KauaʻiiNat 2 · GBIF 5 ✓
Honomanü · MauiiNat 2 · GBIF 4 ✓
ʻAiea · OʻahuiNat 4 · GBIF 2 ✓
Waimea · OʻahuiNat 2 · GBIF 4 ✓
Paumalū · OʻahuiNat 4 · GBIF 2 ✓
Hanakāpīʻai · KauaʻiiNat 2 · GBIF 3 ✓
Waimano · OʻahuiNat 2 · GBIF 3 ✓
Kahana · OʻahuiNat 1 · GBIF 4 ✓
Pūpūkea · OʻahuiNat 2 · GBIF 3 ✓
Honokahua · MauiiNat 1 · GBIF 3 ✓
Waiheʻe · MauiiNat 2 · GBIF 2 ✓
Maunalua · OʻahuiNat 2 · GBIF 2 ✓
Hālawa · OʻahuiNat 1 · GBIF 3 ✓
Kalihiwai · KauaʻiiNat 2 · GBIF 2 ✓
Waiākea · HawaiʻiiNat 1 · GBIF 3 ✓
Mānana · OʻahuiNat 2 · GBIF 2 ✓
Hauʻula · OʻahuiNat 2 · GBIF 1 ✓
Waiʻanae · OʻahuiNat 1 · GBIF 2 ✓
Keaʻau · HawaiʻiiNat 1 · GBIF 2 ✓
Kīlauea · KauaʻiiNat 2 · GBIF 1 ✓
Haʻikū · MauiiNat 1 · GBIF 2 ✓
Hālawa, Napapaʻa · HawaiʻiiNat 1 · GBIF 1 ✓
Honolua · MauiiNat 1 · GBIF 1 ✓
ʻAliomanu · KauaʻiiNat 1 · GBIF 1 ✓
Keaʻau · OʻahuiNat 1 · GBIF 1 ✓
Paʻuwela · MauiiNat 1 · GBIF 1 ✓
Hanakoa · KauaʻiiNat 1 · GBIF 1 ✓
Manukā · HawaiʻiiNat 1 · GBIF 1 ✓
Kawaihāpai · OʻahuiNat 1 · GBIF 1 ✓
Keauhou · HawaiʻiiNat 1 · GBIF 1 ✓
Kaunala · OʻahuiNat 1 · GBIF 1 ✓
Makapala, Niuliʻi · HawaiʻiiNat 1 · GBIF 1 ✓
Kamananui · OʻahuiNat 1 · GBIF 1 ✓
Waipiʻoiki · MauiiNat 1 · GBIF 1 ✓
Kalihi · OʻahuiNat 1 · GBIF 1 ✓
Nāwiliwili · KauaʻiiNat 1 · GBIF 1 ✓
Keʻei 2 · HawaiʻiiNat 1 · GBIF 1 ✓