Z6 



ISOETACEAE 



Stomata present. 



Leaves coarse; stomata numerous. 

 Leaves not coarse; stomata few. 

 Megaspores tuberculate. 

 Megaspores spinose. 

 Amphibious or terrestrial; peripheral strands usually present. 

 Corms 2-lobed; velum incomplete. 

 Corms 3-lobed; velum complete. 

 Leaves more than 8 cm. long. 

 Leaves less than S cm. long. 



3. /. flettii. 



4. I. bolanden. 



5. /. biaunii. 



6. /. howellii. 



7. /. nut t alia. 



8. /. orcuttii. 



1. Isoetes occidentalis Henderson. 

 Western Quillwort. Fig. 7?>. 



Isoetes occidentalis Henderson, Bull. Torrey Club 27: 358. 

 1900. 



Isoetes lacustris var. paupercida Engelm. Trans. St. Louis 

 Acad. Sci. 4: 377. 1882. 



Isoetes paupercula (Engelm.) A. A. Eaton, Proc. U. S. Nat. 

 Mus. 23: 649. 1901. 



Submersed ; corm 2-lobed ; leaves 9-30, rarely 

 60, dark green, rigid, gradually tapering, 5-20 cm. 

 long; peripheral strands and stomata lacking; lig- 

 ule short-triangular; sporangium almost orbicular 

 5-6 mm. long, about one-third covered by velum , 

 megaspores cream-colored, 525-640 \i in diameter, 

 marked with low conspicuous irregular crests, 

 chiefly simple on apical faces, branching to form 

 irregular network on basal face; microspores 

 24-42 ji long, spinulose. 



Mountain lakes, Canadian Zone; Wyoming, Colorado, 

 Idaho, and California. Type locality: "in yi foot of 

 water. Lake Coeur d'Alene, Idaho." 



2. Isoetes piperi A. A. Eaton. 

 Piper's Quillwort. Fig. 74. 



Isoetes piperi A. A. Eaton, Fern Bull. 13: 51. 1905. 

 Isoetes howellii var. piperi Clute, Fern Allies 246. 1905. 



Submersed; corm 2-lobed; leaves 8-26, erect or 

 somewhat spreading, taper-pointed, 3-10 cm., rarely 15 

 cm., long; peripheral strands and stomata lacking; 

 ligule short triangular ; sporangium 4-5 mm. long, one- 

 fifth to two-thirds covered by velum; megaspores white, 

 540-800 n in diameter, marked with points or tubercles 

 and short ridges, sometimes serpentine; microspores 

 29-35 \y„ rarely 42 u long, papillose. 



Lakes in Washington, Transition Zone. Type locality: Green 

 Lake, King County, Washington. 



3. Isoetes flettii (A. A. Eaton) N. E. Pfeiffer. 



Flett's Quillwort. 



Fig. 73. 



Isoetes echinospora var. flettii A. A. Eaton, Fern Bull. 13: 51. 

 1905. 



Submersed; corm 2-loljed; leaves 15-30, coarse, 

 tapering, spreading or recurved, 5-8 cm. long ; periph- 

 eral strands lacking ; stomata numerous : ligule blunt- 

 triangular; sporangium oblong, 4-6 mm. long, covered 

 less than one-half by the velum ; megaspores 480-560 u 

 in diameter, marked with coarse lov/ tubercles and short 

 crests, these usually somewhat distant ; microspores 29- 

 33 yi long, finely spinulose. 



In lakes. Transition Zone; Washington. Type locality: "lake 

 shore in gravel, Spanaway Lake, Pierce County, Washington." 



