What
Egeria is recorded by a competent New Zealand authority as an introduced, invasive or managed threat subject.
The Hit List
Verified public Target identity
freshwater · flora / algae
Egeria
Egeria densa
Also known as Large-flowered oxygen weed
Visual markers
- Submerged leafy stems with leaves arranged in conspicuous whorls, usually four to six leaves at a node.
- The broad whorled leaves separate egeria from lagarosiphon's alternate, downward-curving leaves.
Why
The source identifies ecological, biosecurity or habitat risks that make this subject relevant to NZ Ex Games intelligence.
Where
Distribution and current presence are place-specific and must be established from current authoritative or verified evidence.
Identification notes
- Lagarosiphon: Lagarosiphon has alternate spiral leaves with distinctly downward-curving tips. Compare dossier.
- Hornwort: Hornwort leaves are narrow, forked and bristly rather than broad and undivided. Compare dossier.
Keep in mind: Leaf arrangement needs to be visible; general weed-bed appearance is not sufficient for confirmation.
Established knowledge
For consequential field decisions, consider the knowledge state and cited sources for each claim, and consult authoritative guidance where appropriate. Information and reliance terms
50% reference coverage — not scientific certainty or ecological progress
- Identification
- NZ status
- Ecological impact
- Sources
Open knowledge
These are parts of the public picture that could become clearer with better evidence.
- Distribution
- Visual clues
- Confusion species
- Regional intelligence
Sources & credits
- NIWA — Freshwater invasive species of New Zealand 2020authoritative · Canonical identity, New Zealand status and threat context
- Field guide to aquatic plants of New ZealandNIWA · Aquatic plant identification and comparison
Field observations
Field observations connect sightings and signs with a place, time and source. They can support evidence after review. This dossier does not accept public submissions.
No field observations are published for this Target.
Commentary
Local experience, corrections and context help explain the public record. Commentary is not verified knowledge. This dossier does not accept public comments.
No commentary is published for this Target.
Questions and Missions
What can the sources tell us, and what still needs evidence? Explore dossier discoveries and research questions to understand this Target. Research leads identify knowledge gaps; they are not field assignments.
Explore Missions and Hunt mode for Egeria- Where is egeria currently established or emerging in New Zealand?Research question · evidence needed
- What evidence distinguishes current ecological impact from presence alone for egeria?Research question · evidence needed
Shout Out
Shout Out
Share this record so others can explore the same question, place or ecological work. The link keeps its context and sources together.
Egeria — The Hit List — NZ Ex Games
Canonical link
/hit-list/weed-egeria