CRYPTOGAMIA. 
736. HYMENOPHYLLUM. Sorus marginalis, recepta- 
culo cylindraceo insertus. Indusium bivalve, sorum 
includens. 
V. HYDROPTERIDES. 
737 . ISOETES. Capsula membranacea, non dehiscens, 
frondis basi immersa, 1-locularis. Semina angulata, 
receptaculis pluribus filiformibus inserta. 
73 8. SALVINIA. Indusia imbricata, connata, capsulam 
unilocularem mentientia. Semina receptaculo cen- 
trali inserta. 
f3g. AZOLLA. Capsula unilocularis, radicalis, globosa, 
polysperma. 
I. GONOPTERIDES , 
713. EQUISETUM. Gen.pl. 1614, 
1. E. caulibus sterilibus simpliciter lamosis, ramis scabrius- arvense . 
culis tetragonis, fructificationibus simplicibus, vaginis 
cylindraceis inciso-dentatis, dentibus acutis. Willd. 
enum. 10 65. IVilld. sp.pl. 5. p. 1. 
Icon. Sckkuhr filic. t. 1 67. 
In low and sandy fields : Pensylvania and Virginia, 1/ . 
April, May. v. v. 
2. E. caulibus sterilibus fructificantibusque duplicato-ramo- sylvaticum a 
sis, ramis scabriusculis deflexis tetragonis, ramulis 
subtriquetris. IVilld. enum. 1005. IVilld. sp. pl. 5. 
p. 3. 
Icon. Schkuhr jilic. t. 166. FI. dan. 1182. 
In low shady woods : New York to Virginia. 2/ . April 
— June. v. v. 
3. E. caulibus subramosis, ramis subquaternis tetragonis uliginosum . 
glabris, spica cylindracea terminali. — IVilld. sp. pl. 5. 
p. 4. 
In swamps : New York to Virginia. 2/ . May. v. v. 
Resembles E. limosum. 
4. E. caulibus simpliciter ramosis glabris sulcatis, ramis palustre. 
pentagonis apice spiciferis. IVilld. enum. 1005. 
IVilld. sp.pl. 5. p. 5. 
