ISOETACE^E. 149 



** Trunk tr Holed ; velum nearly or quite complete. 



19. I. Nuttallii A. Br. Trunk almost globose, slightly 

 grooved ; leaves 20 60, slender, bright-green, 3' 9' long, with 

 only three peripheral bast bundles ; sporangia oblong or oval, 

 entirely covered by the velum ; macrospores variable, 0.25 0.50 

 mm. thick, densely covered with minute but rounded warts, or 

 rarely almost smooth ; microspores papillose, brown, 0.025 

 0.028 mm. long. (/. opaca Nutt., /. Suksdorfii Baker.) Oregon, 

 Washington ; western Idaho (Geyer}, Vancouver Island (Ma- 

 coun) ; California (Brandegee). 



20. i. Orcutti A. A. Eaton. Trunk slightly trilobed, glo- 

 bose ; leaves 6 15, 2' 4' long, 3" 3^" broad, triangular, slightly 

 winged at base, with two weak bast bundles and rarely with 

 lateral ones ; velum entire ; ligula lunate or semicircular ; ma- 

 crospores very small, 0.24 0.32 mm. in diameter fuscous when 

 wet, cinereous or glaucous when dry, polished, the surface finely 

 pitted as with pin points ; microspores dark-brown, 0.0220.035 

 mm. long, spinulose. On mesas at San Diego, California (Or- 

 cutt). 



21. I. minima A. A. Eaton. Trunk trilobed, i|"- 2" wide, 

 i" 1 1" high ; leaves 6 12, f i|' long, slender, with four peri- 

 pheral bast bundles; sporangia unspotted, 2" long; velum f f 

 covering the sporangium ; macrospores globose, 0.290.35 mm. 

 in diameter, covered with short, slender blunt spinules, the 

 equatorial commissure pectinate with polished spinules ; micro- 

 spores papillose or sparingly spinulose, white, 0.026 0.031 mm. 

 long. In damp places, Waverly, Spokane County, Washington 

 (Suksdorf). 



