Myriophyllum pinnatum (Walt.) B.S.P.

British Columbia: [locality and coordinates withheld; status in British Columbia: S1 (Critically Imperiled, Red List; BCCDC)],
Full sun, occasional emergent aquatic in 2--5 cm water in shallow pools in extensive marsh, fresh-water intertidal, with Juncus pelocarpus, J. bulbosus, Eleocharis parvula, Lilaeopsis, Limosella, Crassula aquatica, Callitriche heterophylla, Myriophyllum aquaticum, M. hippuroides, M. ussuriense. Anthers 0.6--0.7 mm, 4 stamens/flower, 11--15 leaflets on submerged leaves.

Peter F. Zika 28482, Sep 20, 2016
With Frank Lomer
WTU, Accession: 414458, Barcode: WTU-V-030229