1922] 



PFEIFFER MONOGRAPH OF THE ISOETACEAE 117 



Lac de Guery, 23-27 August, 1861, Motelay misit," Herb. 

 Eaton (Mo. Bot. Gard. Herb.). 



12. I. tenuissana Boreau, Bull. Soc. Ind. d'Angers, 269. 

 1850; Grenier & Godron, Fl. Fr. 3: 650. 1855-56; Milde, Fil. 

 Eur. 285. 1867; Motel. & Vendr. Actes Soc. Linn. Bord. 36: 351. 

 1883; Baker, Fern Allies, 131, 1887, and Jour. Bot. 18: 107. 

 1880; Bot. Centralbl. 57: 246. 1894. 

 /. Viollaei F. Hy, Jour, de Bot. 8: 96. 1894. 

 Calamaria tenuissima Kuntze, Rev. Gen. PI. 2 : 828. 1891-93. 

 Corm 3-lobed; leaves 7-12, 7-12.5 cm. long, 3-angled, erect, 

 slender, gradually tapering from base to apex; stomata fairly 

 common ; peripheral strands not evident ; ligule small, triangular ; 

 sporangia globose, 2-3 mm. long, with velum complete or nearly 

 so; megaspores creamy in color when dry, brown when wet, 

 400-480 n in diameter, with few large warts (4 or 5) on upper 

 faces, more on basal (about 13-15) ; commissural ridges promi- 

 nent ; microspores 25-33 M long, with numerous long, blunt spines. 

 Distribution: Province of Riz-Chauvron, Haute- Vienne, 

 France. 



Specimens examined : 



Central France: Haute- Vienne, without date, Boreau (Gray 

 Herb.); Riz-Chauvron, 25 September, 1856, Schultz (Cha- 

 boisseau} 395 (Mo. Bot. Gard. Herb.); Riz-Chauvron, 

 Haute- Vienne, 5 September, 1865, Schultz (Deloynes} 395b. 

 (U. S. Nat. Herb.) ; Riz-Chauvron, September, 1857, Cha- 

 boisseau (Mo. Bot. Gard. Herb, and Gray Herb.) ; Riz- 

 Chauvron, Haute- Vienne, 7 September, 1859, Chaboisseau 

 (N. Y. Bot. Gard. Herb.) ; Riz-Chauvron, 20-25 September, 

 1860, Chaboisseau 70 (Mo. Bot. Gard. Herb, and Gray 

 Herb.); Riz-Chauvron, 1864, Motelay (Mo. Bot. Gard. 

 Herb.) ; Riz-Chauvron, 8 September, 1865, Chaboisseau 

 (Mo. Bot. Gard. Herb.); Etang du Riz-Chauvron, Septem- 

 ber, 1869, Durieu (Gray Herb.) ; near St. Leomer, Vienne, 

 7 August, 1893, Violleau 427 (Mo. Bot. Gard. Herb.); 

 Etang de La Harpe near Loreux (Loir et Cher), 28 July, 

 1883, Martin 19 (N. Y. Bot. Gard. Herb.); "La Harpe," 

 Loreux (Loir et Cher), 7 August, 1876, Le Grand (N. Y. 

 Bot. Gard. Herb.) ; St. Leomer, Vienne, August, 1893, F. Hy 



