10 6 A SYNOPSIS OF THE SPECIES OF ISOETES. 



23. LFLAcciDA,Slmttlew; A. Br. in Flora, 1846 178.— Rootstock 

 2-lobed. Habit of L echinospora, but leaves much longer, 10-do, 

 1-2 ft long, *-f diam. at the middle, diaphanous, light green, 

 tapering to the point, furnished with accessory bast-bundles and 

 copious" stornata, the edge decurrent from the base short and 

 narrow. Sporange small, pale, oblong, f-f »• lo *S \ vei1 com ' 

 plete. Macrospores small, covered with papillae, which are con- 

 fluent into ridges. Microspores slightly papillose, ^ ■■■• 



Hab. Florida, in deep water. First gathered by Kugel. I. 

 Chapmanni, Engelm., has stouter leaves, about 1£ ft- long, larger 

 macrospores, with less prominent tubercles and ridges, microspores 

 smooth or slightly papillose. 



24. I. setacea, Boso Diet. Hist, Nat. ; A. Br. in Verhand. 

 Branden, 1862, 80.— Kootstock 3-lobed, rarely 2-lobed. Leaves 

 10-80, often a foot long, £ lin. diam. at middle, palp green, 

 opaque, moderately firm in texture, tapering to the point, furnished 

 with copious accessory bast- bundles and stornata, the base suddenly 

 dilated, its Recurrent edge reaching up the lamina about 2 m. 

 Sporange pale, globose ; veil none; tongue as long as the sporange. 

 Macrospores large, pure white, closely finely tubercled all over. 

 Microspores cristate. 



Hab. South of France, in ponds nearly dry in summer. 



25. I. adspeksa, A. Br. Expl. Scient. Alg., tab. 37, fig. 3.— Boot- 

 stock 3-lobed. Habit of I. setacea. Leaves 12-20, 3-9 in. long, 

 £-£ in diam. at the middle, opaque, pale green, moderately firm m 

 texture, furnished with stornata and accessory bast-bundles, the 

 edge decurrent from the base short and narrow. Sporange small, 

 spotted, globose ; veil very narrow ; tongue twice as long as broad. 

 Macrospores with strong ribs and a few large tubercles. Micro- 

 spores prickly or crested. 



Hab. Algeria and South France, in ponds dried up in summer. 



26. I. malinverniana, Cesati & De Not., Ind. Bern. Hort. Bot. 



Genuen., 1858, 3.— Kootstock 3-lobed, reaching an inch in diam. 

 Habit of the large varieties of laaistris, but leaves much more 

 elongated, 20-50 or more, a foot or more long, f-1 lin. diam. at 

 the middle, diaphanous, bright green, tapering gradually to the 

 point, furnished with stornata and accessory bast-bundles, the 

 membranous edge decurrent from the base about 3 in. Sporange 

 large, pale, oblong; veil none; lip as long as the short tongue. 

 Macrospores large, white, muricated all over. Microspores 

 smooth. 



Hab. Aqueducts in Piedmont, Moris ! De Notaris! 



27. I. velata, A. Br. Expl. Sc. Alg., tab. 37, fig. Xi'^ 

 dedpiens and longusima, Bory & Durieu in Flora, 1846, 719. 

 Rootstock deeply 3-lobed. Habit of /. setacea. Leaves 20- o0 9 



I 



the 



moderately firm in texture, pale green, opaque, tapering to tw 

 point, furnished with copious stornata and accessory bast-bunqies 

 a distinct membranous border decurrent from the dilated base to 

 2-3 in. Sporange middle-sized, subglobose ; veil nearly or qui 



