Jepson eFlora
Key to families | Table of families and genera

Key to Myriophyllum

View taxon page for Myriophyllum

(For a list of species in Myriophyllum, use the above link.)

Jepson Manual glossary definitions can be seen by moving your cursor over words underlined with dots.

1. Leaves alternate, or whorled with some scattered single leaves ..... M. hippuroides

1' Leaves whorled (opposite)

2. Plants dioecious; leaves narrow, length 3–4 × width; bracts ± = stem leaves ..... M. aquaticum

2' Plants monoecious; leaves generally wider; bracts < stem leaves.

3. Bracts pinnately dissected; stems green, dark green to ± black-green when dry ..... M. verticillatum

3' Bracts entire or dentate; stems dark green, occasionally red-tinged; generally ± white to pink or dark gray when dry.

4. Leaves dark green when fresh, darker when dry, glaucous; young shoots with >= 1 pair of entire, opposite leaves at base; plants conspicuously rhizomed; flower bracts triangular, 4–10 mm, toothed, glaucous ..... M. quitense

4' Leaves dark green when fresh, generally red-tinged, not glaucous when dry, occasionally waxy from diatoms; young shoots lacking pairs of entire, opposite leaves at base; plants not conspicuously rhizomed; flower bracts lanceolate to ovate or oblanceolate, 1–3 mm, entire to toothed, not glaucous

5. Leaf segments 4–14 pairs; angles, spacing varying throughout leaf ..... M. sibiricum

5' Leaf segments 14–24 pairs; angles, spacing uniform throughout leaf ..... M. spicatum


Citation for the whole project: Jepson Flora Project (eds.) [year] Jepson eFlora, [accessed on month, day, year]
Citation for an individual treatment: [Author of taxon treatment] [year]. [Taxon name] in Jepson Flora Project (eds.) Jepson eFlora, [URL for treatment]. Accessed on [month, day, year].
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