Northern Prairie Wildlife Research Center
Aquatic and Wetland Vascular Plants of the Northern Great Plains
Lythrum L. --loosestrife
Erect, perennial herbs, sometimes rather woody at the base; stems usually
with ascending branches above, prominently 4-angled in the upper part. Leaves
usually mostly opposite below and becoming alternate upward, rarely whorled,
sessile, linear-lanceolate to ovate-lanceolate, reduced to bracts in the inflorescence.
Flowers in showy, terminal, bracteate, spikelike inflorescences, 1-several
in the axils of the bracts, regular or somewhat irregular, dimorphic or trimorphic,
the stamens and styles of 2 or 3 different lengths. Calyx tube cylindrical,
green-striate due to the 8-12 strong nerves, the lobes alternating with
slender appendages; petals 6, purple; stamens 6 or 12; ovary 2-celled.
Capsule ovoid, firm, septicidal, enclosed by the calyx tube.
Shinners, L. H. 1953. Synopsis of the United States species of
Lythrum (Lythraceae). Field and Lab. 21:80-89.
||Flowers solitary in the axils of the bracts; calyx
tube glabrous; stamens usually 6.
||Flowers mostly 2-several in the axils of the bracts;
calyx tube pubescent; stamens usually 12, with 6 exserted and 6 included
by the calyx tube.
30. Lythraceae, the Loosestrife Family
2. Lythrum L. -- Loosestrife
- 1. Lythrum alatum Pursh
- 2. Lythrum salicaria L. -- Purple
Return to Family -- Lythraceae - The Loosestrife
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