Mamlia. MAUSILIACE.E. iJOl 



s|)(ires (0.15 to 0.23 of a lino wide) bo.sct witli miimto i)oiiits and wiinklos ; niicro- 

 sporos (.013 to .015 oi" a line long) more or less i)apillose or spinulosc, deep brown. — 

 Anier. Naturalist, viii. 214. 



Poiiils and shallow lakes on the Sierra Nevada at 5,000 to 10,000 feet altitude, in several 

 places {Bolandcr) ; also near Yellowstone Lake, I'arrij. 



2. I. pygmaea, Engelm. 1. c. Deeply submerged, having few (5 to 10) short 

 (I to 1 Lnch long) stout raj)idly tapering dark-green leaves, with very short often 

 even square epidcrniis-cells, without stoniata or ba.st-bun(lk'S : sporocarp circular with 

 a very narrow velum ; macrospores (0.18 to 0.25 of a line wide) marked with smaller 

 and jnor(3 regular, nirely coidhient, rather shar[) points; micro.s[)ores (.012 to .014 of 

 a line long) brown, very minutely jiaijillose or almost smooth. 



In laige patches in mud covering gravel, deeply submerged in running water, on the Mono 

 trail, eastern declivity of the Sierra Nevada, at 7,000 feet altitude, Bolandcr, 1866. Closely 

 allied to the last species, distinguished by its stout short leaves without stoniata, the markings 

 of the larger macrospores, etc. ; in many respects near /. lacuslris. 



I. Ni:irAr.i-ii, Al. Miaiin, a terrestrial species, with triangular leaves 3 to 7 inches long, having 

 numerous stoniata, the oblong sporocarp entindy covered by the velum, and the macrospores 

 minutely verrucose, occurs in Oregon and is to be sought for in Northern California. 



Order CXXIV. MARSILIACE.2E. 



Perennial plants rooted in nmd, having a sleniler creeping rhizome and either 



filiform or 4-parted long-petioled leaves ; the somewhat crustaceous several-celled 



conceptacles borne on peduncles M'hich rise from the rhizome near the leaf-stalks 



or are more or less consolidated with the latter, and contain both macrospores and 



microspores. 



The order consists of two genera of similar habit. In Iwth the leaves or leaf-stalks are circinate 

 in vernation. The macrospores have a minute teiniinal papilla, which produces a small prothal- 

 lus bearing a few archegonia, fertilized by antherozoids formed within the microspores, 



1. MARSILIA, Linn. 



Concei)taclos or sporocarps ovoid or Itoan-shapetl, composed of two vertical valves 



having several transverse compartments or sort in each valve ; tlio .sori composed of 



both macros[)orangia and microsporangia. The sporocarps are provided with a ring, 



which is the outer part of the vertical dissepiment, and which at the ojiening of the 



valves swells up and becomes a mucilaginous filament, tearing the sori from their 



places within the valves. — Plants with peltately quadrifoliolate leaves on slender 



petioles; the sporocarps peduncled and rising either from the petiole or from the 



rhizome at the base of the petiole. 



About 50 species are known, of which 5 or 6 occiu- in the United States. The plants commonly 

 grow in mud under shallow water and have floating leaves, but are sometimes teirestrial. In 

 many species the sjwrocarp has two short teeth near its insertion on the peduncle. 



1. M. vestita, Hook. <^ Grev. Leaflets broadly cuneate, usually hairy, entire, 

 2 to 7 lines long and broad.; jjctioles 1 to 4 inches long : peduncles free from the 

 petiole ; sporocarps solitary, short-peduncled, about 2 lines long, very hairy when 

 young ; upper tooth longest, acute, straight or curved ; lower tooth obtuse, the sinus 

 between tliem rounded. — Ic. Fil. t. 159 ; Engelm. Ainer. Journ. Sci. 2 ser. iii. 55 ; 

 Al. Ihaun, in ^lonatsb. Acad. IJerlin, 1803, 423. J/, villosa, Urackenridge, Ferns 

 of U. S. Kxpl. Exp. 340, as to the American plant. 



Collected in California by Di: I'icWn'uf/, and in upland soil at Mrownsville, Yuba County, 

 yt. Wood; Oregon to Texas, ^f. luucrmutla, Al. Ibaun, is a form of this Hpecien willi longl-r 

 l>eduncles and less hairy spoiocarps. 



