34 



MARSILEACEAE 



1. Marsilea vestita Hook. & Grev. 

 Hairy Pepperwort. Fig. 69. 



Marsilea vestita Hook. & Grev. Icon. Fil. 2: pi. 159. 



1831. 

 Marsilea iniicroiiata A. Br. Am. Tourn. Sci. II. 3: 55. 



1847. 



Rhizomes wide-creeping, clothed with dense 

 tufts of ferruginous or fulvous silky hairs at 

 the nodes. Leaves few or many, arising from 

 the nodes, mostly 5-20 cm. long, ascending; 

 petioles slender, deciduously hairy; blades 1-3 

 cm. broad; leaflets broadly cuneate, spread- 

 ing or folding together, 5-15 mm. long, nearly 

 as broad, entire or nearly so, deciduously 

 hairy. Peduncles nearly or quite free from the 

 petiole, short; sporocarps solitary, 4-8 mm. 

 long, 3-6 mm. broad, at first densely hairy ; 

 upper tooth rather long, acute, usually curved ; 

 lower tooth short, blunt; sori 9-11 in each 

 valve. 



Edge of ponds, ditches, and rivers, Upper and 

 Lower Sonoran Zones; British Columbia to southern 

 California, east to South Dakota, Kansas, Oklahoma, 

 and Te.xas. Type locality: Columbia River region. 



2. Marsilea oligospora Goodding. 

 Xelson's Pepperwort. Fig'. 70. 



Marsilea oligospora Goodding, Bot. Gaz. 33: 66. 1902. 



Rhizomes long-creeping or not, the internodes often very 

 short, the plants appearing tufted. Leaves numerous, 3-8 cm. 

 long, erect or ascending; petioles slender; blades 1-2 cm. 

 broad; leaflets broadly cuneate, spreading or folding together, 

 5-10 mm. long, 3-11 mm. broad, entire, soft-hairy or glabres- 

 cent. Peduncles 5-15 mm. long, united basally with the base 

 of the petiole; sporocarps solitary, 4-6 mm. long, 3-5 mm. 

 broad, densely covered with appressed hairs, glabrescent ; 

 upper tooth a short rounded tubercle, or obsolete ; lower tooth 

 short, blunt ; sori 5-8 in each valve. 



River banks and bottoms of drying ponds and marshes, chiefly in the 

 Transition Zone; Washington to Montana, south to California (Tulare 

 County), and Wyoming. Type locality: Jackson's Hole, Wyoming. 



2. PILULARIA L. Sp. PI. 1100. 1753. 



Very small, inconspicuous plants of muddy situations, with slender long-creeping rhi 

 zomes, the nodes bearing 1 or several minute filiform leaves. Sporocarps globose, short- 

 pedunculate, axillary, longitudinally 2-4-celled, dehiscing by as many valves at the apex; 

 j^=a^^^^ cells (sori) with parietal cushions bearing megasporangia 



\f below and microsporangia above, the former with solitary 



megaspores, the latter with numerous microspores. [Name 

 Latin, meaning a little ball, alluding to the sporocarps.] 



A widely distributed genus of 6 species, only the following occurring 

 in Xorth America. Type species, Pilularia globulifera L. 



1. Pilularia americana A. P>r. 

 American Pilularia. Fig. 71. 



Monatsb. Kon. Akad. Wiss. Berlin 1863: 



Pilularia ainericana A 

 435. 1863. 



Br. 



Rhizome filiform, wide-creeping; leaves setiform, 2-4 cm. 

 long, solitary or not, the nodes rooting beneath. Sporo- 

 carps about 2 mm. in diameter, attached laterally to a 

 short descending arcuate peduncle, 2-4-celled (usually 3- 

 celled) ; megaspores 10-17 in each cell, not constricted in 

 the middle. 



Clayey depressions and desiccating pools, mainly in the Upper So- 

 noran Zone; Oregon (Crook County) to southern California; also i« 

 Arkansas. Type locality: Fort Smith, Arkansas. 



