Class
Family
Genus
Classification
Nomenclature
Scientific Name:
Myriophyllum robustum Hook.f., Handb. New Zealand Fl. 67 (1867)
Vernacular Name(s):
Stout water milfoil
Description
Stout perennial herb; stems to 30 cm tall, prostrate to erect. Lvs all whorled, slightly dimorphic. Submerged lvs often decaying early, in whorls of 5–7. Aerial lvs yellow-green to subglaucous, crowded towards tips of stems, spreading, in whorls of (4)–5–7, oblong, (15)–20–35 × (4)–6–10 mm, becoming smaller near water surface, pectinate, with 26–32 filiform to linear pinnae. Fertile aerial lvs similar to other lvs. Fls ☿. Bracteoles ovate to orbicular, 0.7–0.8 × 0.7–0.8 mm. Sepals 4, ovate to deltoid, 0.6–0.8 × 0.5–0.6 mm; petals 4, weakly hooded, 2.5–3.4 × 1.1–1.2 mm. Frs globular to slightly obturbinate, 1.5–2 (excluding sepals) × 2–2.5 mm, with a few small tubercles on keel of mericarps.
[From: Webb et al. (1988) Flora of New Zealand. Volume 4.]
Biostatus
Indigenous (Endemic)
Phenology
Flowering: Oct.–Mar.; Fruiting: Oct.–Mar.
Bibliography
de Lange, P.J.; Norton, D.A.; Courtney, S.P.; Heenan, P.B.; Barkla, J.W.; Cameron, E.K.; Hitchmough, R.; Townsend, A.J. 2009: Threatened and uncommon plants of New Zealand (2008 revision). New Zealand Journal of Botany 47: 61–96. [Declining]
de Lange, P.J.; Norton, D.A.; Heenan, P.B.; Courtney, S.P.; Molloy, B.P.J.; Ogle, C.C.; Rance, B.D. 2004: Threatened and uncommon plants of New Zealand. New Zealand Journal of Botany 42(1): 45–76.
de Lange, P.J.; Rolfe, J.R.; Barkla J.W.; Courtney, S.P.; Champion, P.D.; Perrie, L.R.; Beadel, S.N.; Ford, K.A.; Breitwieser, I.; Schönberger, I.; Hindmarsh-Walls, R.; Heenan, P.B.; Ladley, K. 2018: Conservation status of New Zealand indigenous vascular plants, 2017. New Zealand Threat Classification Series. No. 22. [Declining]
de Lange, P.J.; Rolfe, J.R.; Champion, P.D.; Courtney, S.P.; Heenan, P.B.; Barkla, J.W.; Cameron, E.K.; Norton, D.A.; Hitchmough, R.A. 2013: Conservation status of New Zealand indigenous vascular plants, 2012. New Zealand Threat Classification Series 3. Department of Conservation, Wellington. [Declining]
Hooker, J.D. 1867: Handbook of the New Zealand Flora: a systematic description of the native plants of New Zealand and the Chatham, Kermadec's, Lord Auckland's, Campbell's, and Macquarrie's Islands. Part II. Reeve, London.
Orchard, A.E. 1979: Myriophyllum (Haloragaceae) in Australasia. 1. New Zealand: a revision of the genus and a synopsis of the family. Brunonia 2: 247–287.
