Isoetes lacustris
Walter Hood Fitch - Illustrations of the British Flora (1924) - Permission granted to use under GFDL by Kurt Stueber. Source: www.biolib.de - Permission is granted to copy, distribute and/or modify this image under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".

Isoetes lacustris
Picture modified from Gilg, Ernst; Schumann, Karl - Das Pflanzenreich Hausschatz des Wissens (1900) - Permission granted to use under GFDL by Kurt Stueber. Source: www.biolib.de - Permission is granted to copy, distribute and/or modify this image under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License.

Isoetes lacustris
USDA-NRCS PLANTS Database / Britton, N.L., and A. Brown. 1913. An illustrated flora of the northern United States, Canada and the British Possessions. Vol. 1: 51.

Isoetes lacustris
Picture modified from Thomé, Otto Wilhelm - Lehrbuch der Botanik fur Gymnasien, Realschulen, forst- und landwirthschaftliche Lehranstalten, pharmaceutische Institute etc. sowie zum Selbstunterrichte. 2. Auflage. (1872) - Permission granted to use under GFDL by Kurt Stueber. Source: www.biolib.de - Permission is granted to copy, distribute and/or modify this image under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled GNU Free Documentation License.

Isoetes lacustris
USDA-NRCS PLANTS Database / USDA NRCS. Wetland flora: Field office illustrated guide to plant species. USDA Natural Resources Conservation Service. - Not copyrighted image

Isoetes lacustris
W. Carl Taylor - USDA-NRCS PLANTS Database / USDA NRCS. 1992. Western wetland flora: Field office guide to plant species. West Region, Sacramento. - Not copyrighted image

Isoetes lacustris
Hippolyte Coste - Flore descriptive et illustrée de la France, de la Corse et des contrées limitrophes, 1901-1906 - This image is in public domain because its copyright has expired.

Isoetes lacustris
Otto Wilhelm Thomé: Flora von Deutschland, Österreich und der Schweiz (1885) - Permission granted to use under GFDL by Kurt Stueber. Source: www.biolib.de Permission is granted to copy, distribute and/or modify this image under the terms of the GNU Free Documentation License, Version 1.3 or any later version published by the Free Software Foundation; with no Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts. A copy of the license is included in the section entitled "GNU Free Documentation License".