:^ 



Fig. 6: 1, Equisetum laevigatum: 1, basal and upper sections of fertile stem (x 1) 

 and somewhat enlarged sheath. 2, Equisetum hyemale var. affine: 2, several sections 

 of fertile stem (x 1) and somewhat enlarged sheath. 3, Equisetum kansanum: 3, upper 

 section of fertile stem, x 1. 4-7. Sclagim-Ua apoda: 4, fertile plant, x 1; 5, fertile spike, 

 X 5; 6, sporophyll, x 10; 7, foliage leaf, x 10. (In part from Correll in Lundell's Flora 

 of Texas, Vol. 1, PI. 2.). 



