USGS - science for a changing world

Northern Prairie Wildlife Research Center

  Home About NPWRC Our Science Staff Employment Contacts Common Questions About the Site

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.

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
Return to Contents

Accessibility FOIA Privacy Policies and Notices

Take Pride in America logo logo U.S. Department of the Interior | U.S. Geological Survey
Page Contact Information: Webmaster
Page Last Modified: Saturday, 02-Feb-2013 06:38:30 EST
Sioux Falls, SD [sdww54]