Scientific Name:
Ceratophyllum demersum L., Sp. Pl. 992 (1753)
Vernacular Name(s):
Common coontail; Hornwort; Lakeweed

Delicate submerged or floating aquatic herb; stems 30–150 cm long. Lvs whorled, dark green, stiff, 1–2× forked, 10–30 mm long; segments filiform to linear, denticulate, bristle-tipped. Nut black, 4–5 mm long; face smooth; basal spines 2, reflexed; terminal spine (style) 4–6 mm long.

[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]

Biosecurity New Zealand 2012: Regional Pest Management Strategies Database.
Biosecurity New Zealand 4 Aug 2011: Unwanted Organisms Register.
Biosecurity New Zealand 2008: National Plant Pest Accord. MAF Biosecurity New Zealand, Wellington.
Howell, C. 2008: Consolidated list of environmental weeds in New Zealand. DOC Research & Development Series 292: 42.
Linnaeus, C. 1753: Species Plantarum. Impensis Laurentii Salvii, Stockholm.
Ministry for Primary Industries 23 Feb 2017: Unwanted Organisms Register. Version 02.01.02.