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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.

Reference:

Shinners, L. H.  1953.  Synopsis of the United States species of 
     Lythrum (Lythraceae).  Field and Lab. 21:80-89.

Lead Characteristic Go To
1 Flowers solitary in the axils of the bracts; calyx tube glabrous; stamens usually 6. L. alatum
1 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. L. salicaria


30. Lythraceae, the Loosestrife Family
2. Lythrum L. -- Loosestrife
1. Lythrum alatum Pursh
2. Lythrum salicaria L. -- Purple loosestrife


Return to Family -- Lythraceae - The Loosestrife Family
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