QG A SYNOPSIS Oh THE SPECIES OF ISOETES. 



Veil nearly or quite complete. 



27. 7. velata. 28. 7. Perralderiana. 29. 7. dubia. 30. 7. tcyulensis. 



31. 7. Boryana. 32. 7. tenuissmia. 33. 7. olymjrica. 



Species of Tropical Africa. 



34. 7. Welwitschii. 35. 7. nigritiana. 36. 7. Schiveinfurthii. 



37. 7. (cquinoctialis. 



Species of Japan and Tropical Asia. 

 38. 7. japonica. 39. 7. coromandelina. 40. 7. brachyylossa. 



Species of Australia. 41. 7. tripus. 



Species of Tropical America. 

 42. 7. amazonica. 43. 7. cabana. 44. 7. Gardneriana. 



Group 4. Terrestres. 

 45. I. Duriari, 46. I. Hystri.r. 



Group 1. Aquatics. — Species inhabiting lakes and ponds 

 where they are permanently submerged. Leaves without 

 stomata, accessory bast-bundles, or persistent bases. 



1. I. triquetra, A. Br. in Verb. Branden, 1862, 36. — I. andina, 

 Spruce MSS. — Rootstock very thick (nearly 1 in. diam.), 2-lobed. 

 Leaves 60-100, stiffly erect, firm in texture, dull green, 2-3 in. 

 long, one-sixth in. broad at the middle, with a channelled tri- 

 quetrous tip, and a distinct crisped border reaching from the base 

 half way up, without either stomata or accessory bast-bundles. 

 Sporangia oblong, truncate at the apex, \ in. long, copiously dotted ; 

 veil none. Macrospores obscurely tubercled between the ridges, 

 more distinctly tubercled on the lower half. Microspores smooth, 

 brown or white. 



Hab. Andes of Quito, Spruce! Peru, Lechler. 



2. I. Gunnh, A. Br. in Berl. Monatber., 1868, 535.— Rootstock 

 3-lobed. Leaves 50 or more, stiffly erect, opaque, dark green, 

 2-3 in. long, T ' T in. broad at the middle, nan-owed suddenly at the 

 tip, with a short brown uncrisped border running up from the 

 base, without stomata or accessory bast-bundles. Sporange small, 

 orbicular; veil none. Macrospores large, smooth, chalk-white. 

 Microspores smooth. 



Hab. Tasmania, forming large masses in the mountain-lakes, 

 alt. 3500-4000 feet, Gunn, 1563 ! 



3. I. elatior, F. M. ; A. Br. in Linnsea, xxv. (1852), 722; Berl. 

 Monat., 1868, 536.—/. tmmauica, F. M. ; Durieu in Bull. Bot. Fr. 

 1864, 101, ex parte.— -Rootstock 3-lobed. Habit of I. lacustris. 

 Leaves 30-50, flaccid, dark green, diaphanous, reaching a foot in * 

 length, £ 1m. broad at the middle, the lanceolate base running up 

 the edge as a distinct membranous uncrisped border for 3-4 in., 

 without stomata or accessory bast-bundles. Sporange small, 

 brown orbicular, unspotted; veil none. Macrospores small, 

 white hnely granular. Microspores smooth. 



Hab. Tasmania, in lakes, Archer ! 



