A SYNOPSIS OF THE SPECIES OF ISOETES. 107 



complete; lip very short ; tongue lanceolate. Macrospores middle- 

 sized, minutely tubereled between the ribs, more prominently 

 tubercled on the lower half. Microspores spinulose. 



Hab. Mediterranean region, from Spain to Asia Minor. 



28. I. Peralderiana, Durieu & Letourn. in Kralik PL Alg. Exsic, 

 157.— Eootstock 3-lobed. Leaves 12-20, £-1 ft. long, *- lin. diam. 

 at the middle, opaque, pale green, moderately firm in texture, 

 furnished with copious stomata and accessory bast-bundles, the 

 membranous border towards the base less distinct than in velata. 

 Sporange pale, globose, -^ in. long ; veil nearly or quite complete ; 

 lip truncate ; tongue lanceolate. Macrospores middle-sized, 

 minutely tubercled, Microspores densely spinulose. 



Hab. Algeria, Kralik, 157 ! Very near velata. 



29. I. dubia, Gennari Comment., ii., 104. — Eootstock 3-lobed. 

 Leaves about a dozen, very slender, 6-8 in. long, |— | lin. diam. at 

 the middle, opaque, pale green, with stomata and a few obscure 

 accessory bast-bundles, the border decurrent from the base short 

 and narrow. Sporange small, pale, globose ; veil complete ; lip 

 truncate ; tongue short, broad ovate. Macrospores like those of 

 velata. Microspores dimorphous, some crested, some spinulose. 



Hab, Island of Magdalena, off Sardinia, Gennari! Very near 



velata. 



30. I. tegulensis, Gennari Comment., ii., 10G. — Eootstock 

 3-lobed. Leaves 10-20, very slender, ^-1 ft. long, J-f lin. diam. 

 at the middle, opaque, pale green, furnished with stomata and a 

 few weak accessory bast-bundles, the border decurrent from the 

 base short and narrow. Sporange small, pale, globose ; veil 

 nearly or quite complete ; tongue and lip both short. Macrospores 

 middle-sized, minutely tubercled. Microspore dimorphous, some 

 spinulose, some crested. 



Hab. Sardinia. Very near velata. The Spanish /. butiea, 

 Willk. & Lange Prodr. Fl. Hisp., i., 15, is either the same or a 

 close ally. 



31. I. Boryana, Durieu in Bull. Bot. Soc. France, viii. (1861), 

 164. — Eootstock 3-lobed. Habit stouter than in velata. Leaves 

 10-30 or more, 4-8 in. long, £ lin. diam. at the middle, pale 

 green, opaque, tapering gradually to the point, furnished with 

 abundant stomata and accessory bast-bundles, with a broad 

 Membranous border shortly decurrent from the dilated base. 

 Sporange oblong or subglobose, pale ; veil complete ; tongue and 

 up both short. Macrospores middle-sized, with minute tubercles 

 between the ribs and larger ones over the lower half. Microspores 

 dimorphous, some crested, some spinulose. 



Hab. Marshes of the Landes, Gay ! Durieu! 



82. 1. tenuissima, Boreau in Bull. Angers, 1850, 259. — Eoot- 

 stock small, usually 3-lobed, rarely 4-lobed. Leaves 12-20, very 

 slender, 3-4 in. long, J-4 lin. diam. at the middle, opaque, pale 

 g^en, tapeiing gradually to the point, furnished with stomata and 

 usually a few weak accessory bast-bundles, with a short broad 



