Myriophyllum spicatum L.
FamilyHaloragaceae — APG family: Haloragaceae
DescriptionStem 2-3 mm thick at base from elongated, creeping rhizome; leaves pinnate, usually forming whorl, slightly longer than internodes; spike emerging above water; flowers in axis of bracts, shorter or barely longer than flowers; pistillate flowers with small petals, staminate with larger petals; stamens 8.
EcologyShallow water.
Most specimens belong to subsp. exalbéscens (Fern.) Hult. (M. exalbescens Fern.), with fewer (6-11) pairs of leaf segments and short bracts, not exceeding the flowers; but others with more numerous leaf segments and longer bracts also occur. M. spicatum described from Europe, subsp. exalbescens from York River (Gaspé).
Hultén's Flora About

This is a digital representation of Eric Hultén’s ‘Flora of Alaska and Neighboring Territories: A Manual of the Vascular Plants’, which was published by Stanford University Press in 1968. The book was digitized by C. Webb (at UAMN) as part of the Flora of Alaska project, with funding by the US NSF (Grant 1759964 to Ickert-Bond & Webb), and with permission of Stanford University Press. Data and images © 1968 Board of Trustees of the Leland Stanford Jr. Univ. Usage licence: Creative Commons BY-NC-SA 4.0. NB: You may find OCR errors; please refer to the hard-copy if in doubt.