Isoetes (QUILLWORT) 



A. Classification: 



Division III. Pteridophyta. l 

 Class I. Eusporangiatae. 

 Order. Isoetales. 

 Family. Isoetaceae. 

 Genus. Isoetes. 



Species, (e.g.) lacustris L. 



B. Habitat: 



Some forms grow on the bottom of ponds, others in 

 moist meadows, or on the margins of bodies of water. 



THE SPOROPHYTE 



C. Naked-eye Characters: 



1 . General Features. 



(a) Note the differentiation of the plant into root 

 and shoot, and of the shoot into stem and leaf. 



(b) Make a sketch, natural size, showing the 

 general appearance of the entire plant. 



2. The Stem. 



(a) Without removing any of the leaves or roots, 

 ascertain all you can about the shape, size, 

 branching, and other characters of the stem, 

 and describe. 



(b) With a sharp scalpel, make a cross-section of 

 the stem through the middle, being careful not 

 to remove any of the leaves or roots. 



(c) Describe the outline of the stem as seen in 



1 Se^ "ote, p. 148. 



149 



